can someone explain heavy, light for caliber

[Scibaer]

i read the terms, heavy for caliber or light for caliber, in some threads
 can someone shed some light on this theory for me ?

[mcwoodduck]

Sure.
Lets talk 308 sized Bullets.
They come in molded bullets from 110 to 220.
In a particular caliber like 308 Win or 30-06.
The 110, 125, and 130's are light for caliber with the 150, 165, and 180  being normal for caliber and the 200 and 220 's being heavy.
The same 130's that are light for 308 are about normal for the 270 + 6.5mm
And the 220's that were heavy for 308 are about normal for 338's.
It is a lenght vs Width kind of thing that I may not be describing well.

[Scibaer]

ok, so does that suggest that there is an optimum weight bullet for any given caliber ?
or does that suggest that then someone handloads , a light or heavy for caliber bullet will need more work, when working up a load, for any given caliber ?

[mcwoodduck]

Yes and NO.
Yes there is a bullet shape and weight that will give you best proformance in a particular rifle cartridge.
No, The neat thing is you can talor the projectile to your type of shooting or hunting.
A round is designed with a certain criteria in mind.
Bullet weight, over all ctg length to work in certain actions and the powder available.
Let's look at 30-30.  It was designed to work with heavier bullets.  You can tell by how long the neck is.
The 170 grain bullet will sit to the bottom of the neck and the belled part of the case if for powder, again this goes back to Black Powder ideas where you filled the case and sat the projectile on the black powder to avoid spikes( something I learned the other day on the GBO chat do hickey) in pressure.  Sitting a heavier bullet 220 grains in a 30-30 case will extend beloe the neck and take up case capacity with the same over all CTG length.  but if all you had were 220's the nthey would be perfect at 1800 - 2100 FPS for deer in the thick woods.  now take that same load out to the fields and you will have a gate way arch type trajectory.  You may want to go with a lighter bullet that can make more room for powder in the case like the 150 grain.  If you are looking for even smaller game at longer ranges smaller projectiles may still be needed in the 110 to 125 grain catagory.
Then you get in the the twist of the barrel.  and some rifles are not made to shoot heavier or lighter slugs.  the twist on an M1 carbine that shoots the 110 grain bullet is different than the M1 Garand that is made to shoot 150 grain bullets.  and no mater how you load you may not be able to get light or heavier loads to work out of the rifle you have / want.  in other words you are not going to be able to order a Weatherby Mk V in 300 WBY that is set up to shoot 180 grain slugs (you will be able to work up loads for either side of it with 150 to 220 but you will not be able to make 125 grain bullets work well as a super ground hog lighting killer.

[Scibaer]

ah, ok. now i see where the rifling twist rates come into play.
 ok this is all falling into place now
so that is why they dont talk about being light or heavy for caliber in handguns so much as they do for rifles ?
 its more about stabilization at a given range, and you normally dont shoot 150+ yards with handguns...

[mcwoodduck]

Yep,
With calibers like 45 Colt they do have light and heavy from 180 to 300 grains.
But for the most part the size of the bullet is not going to change drasticly in a given caliber because they are already kind of squatty.  and a disk would be hard to load.
Then you take into account the actoing of most Semi Auto's need a bullet X heavy for the springs to work.

[Scibaer]

well thanks duck
 you made this pretty simple to understand
i think i got it now
 thx, glenn

[mcwoodduck]

Good Cause I think I confussed my self.    
 

[AtlLaw]

I never considered the normal bullet weight for a given caliber as a range.  "Normal" bullet weight means one, singular.  The 165 gr .308 bullet for example.

I've always been one of those people who get all excited studying ballistic charts and and playing "what if" and "How about," which is probably why I never thought of a normal "range" of bullet weights!   

So let me tell you the basis of my "Optimum Bullet Weight" theory.  Two words: Sectional Density (SD).  Back in the day, when cup and core bullets were just about all there were, excepting the partition of course, penetration was the issue.  And I am of the type that desires a hole in and a hole out.  Conventional wisdon of the time equated penetration to sectional density, ergo after a detailed study of popular bullet weights for given calibers, I settled on the rule that my "normal" bullet weight for a given caliber would have a SD of .250 +/- a bit.  i.e.  .308 caliber = 165 gr. bullet weight where SD = .248.

Using this rule I can select a bullet weight for any given caliber and be assured it is perfectly adequate.     Uh,    for Medium game that is...  Remember, we have small, medium, large and dangerous game to consider when we choose a bullet!

So, to pick the actual weight bullet we will use in a given situation we have to combine the normal weight for a caliber based on our rule for it's selection with our desires or rules for specific velocities, the intended game, bullet construction and whatever other factor we may come up with!     OH! And these popular mono metal bullets have just added another level!   

In reality, I select a "normal" bullet weight for a given cartridge rather then caliber.     This variation has evolved as another of my beliefs is that the reason for a bigger (more powder capacity) cartridge is to drive a heavier bullet at the same (given) velocity that a smaller cartridge of the same caliber drives a lighter bullet.  So, for me, the normal weight bullet for the 308 Win is 150 gr., in the 30/06 it is the 165 gr. and in my 300 Win Mag it is 180 gr.   

   Which actually means... um... er... that I consider the normal bullet weight for the .308 caliber to be in the range of 150 grains to 180 grains...         

good explanation there McWoody... 

[Scibaer]

ok, i have read your statements a few times.
i dont disargee with anything you've said specifically
mostly because im just now getting an understanding of this topic

but, wouldnt your 165 grain bullet for the .308 be the optimum weight for that caliber ?
would not the 150 grainers be light for that caliber, and the 180's be the heavies ?

interesting stuff , aint it ? lol

i guess part of  my question was, why point it out ? the light for caliber statement makes certain implications. is there some reason why knowing if the bullet you have selected be light ( too light ? ) or too heavy to be optimum for accuracy or stabilization ? or is it more of the urban legend of reloading, or some over thinking it ?

[AtlLaw]

is there some reason why knowing if the bullet you have selected be light ( too light ? ) or too heavy to be optimum for accuracy or stabilization ?

OH!     You talkin optimal bullet weight for stabilization!     Well, that's something entirely different based on another given...     No, wait, you talkin 'bout optimum bullet weight for accuracy!    

  okay... I'm confused...    Is you shooting hide or paper?  no, that's not the right question either...    Oh I see!  Now you're saying "optimum" bullet weight instead of "normal" (standard, average whatever you want to call it) bullet weight for caliber...   

Never mind...    Talk to McWoody... 

 

[Scibaer]

richard,
 what i wanted to know was, the theory of "light for caliber"  and or "heavy for caliber" statements
when someone makes that statement, when talking about working up a handload, thats makes me think, that certain implications apply.
like getting POI accuracy with less then stable bullets, or some other ballistic parameter.
and since any given caliber or cartridge can and does use a variety of bullet weights,  i was under the impression that some other aspect of handloading was eluding me. i was only asking, but i hear it alot and dont understand why these "parameters" of light or heavy are being discussed.

as a side note, there must be a good reason why there is a "popular" bullet weight for any given cartridge or caliber, right ?
like the 240 grain bullet for the .44 mag or the 158 grain bullet for the .357 mag.. we could call them the "optimum" bullet weight for those calibers.
 that could be , because handloaders have found out that those weight bullets worked best for , lets say hunting.
so by saying 'light for caliber" could be a fancy way of saying 'lighter then optimum" ?
now Duck said that , for example a 220 grain .308 caliber bullet is " heavy for caliber" in a .308 but "optimum" in a .338 cartridge , where a 180 grain bullet would be 'light for caliber' in a .338 cartridge ..

so the implication is, that its talking about bullet weight selection, for working up any given load for any given cartridge , and not really referring to
the other things we have touched on here.

no smileys were harmed in this thread, lol

[Autorim]

Scibaer,

IMHO, bullet weights become "standard" or optimum because that is what the factory loaded when the cartridge was first introduced - same with military rounds.

.357 - 158 grain
.44 mag - 240 grain
.44 spl - 246 grain
.222 - 50 grain
.41 mag - 210 grain
.45ACP - 230 grain
 
and so on, but there are lots of variables. FWIW - in all of my hunting rifles, I tend to load heavier bullets to gain sectional density and BC

.257 - 125 grain
.270 - 150 grain
30-06 - 165 or 180 grain
.338 mag - 225 or 250 grain although that 200 grain Nosler Accubond looks good


More confusion?

Ken

[AtlLaw]

no smileys were harmed in this thread,

I have to use smileys!  So much is lost in the inflectionless dryness of the written word.      What does someone that talks in a monotone do?  PUT YOU TO SLEEP!  THAT'S WHAT!

what i wanted to know was, the theory of "light for caliber"  and or "heavy for caliber" statements

This is getting too serious for my taste, and my fingers hurt!  But,
I don't think there is a "theory" that you can quote in this area.  What you have is an opinion of the speaker based on his definition of what is the median weight for a given caliber.  You can't really say "normal" where there is no norm, eventhough some weights may be more popular then others.  You can't say optimal unless you define the expectations of the bullet.  So, next time someone makes such a statement, ask them why they believe said weight is light or heavy for caliber.  Their opinion is as valid as anyone elses because they have defined the criteria for their definition.

when someone makes that statement, when talking about working up a handload, thats makes me think, that certain implications apply.  like getting POI accuracy with less then stable bullets, or some other ballistic parameter.  and since any given caliber or cartridge can and does use a variety of bullet weights,  i was under the impression that some other aspect of handloading was eluding me. i was only asking, but i hear it alot and dont understand why these "parameters" of light or heavy are being discussed.

See my previous statement.  There is no hard and firm meaning that I am aware of.  Therefore, the meaning would depend on the context of the L or H discussion.
   

there must be a good reason why there is a "popular" bullet weight for any given cartridge or caliber, right ?

Right!  But you are making the mistake of trying to identify one. single universal reason.  As far as I know there ain't one.  I gave you my reasoning behind my choosing the 150 to 180 grain bullets as a range, and the 165 gr. as the median.

we could call them the "optimum" bullet weight for those calibers.

I don't think, as if anybody cares what I think, that we can.  This is my whole point.  You have to define the parameters of your desires and expectations before you can start applying a given bullet's characteristics, of which weight is just one, before you can select one that is, in your opinion, and probably only in your opinion, optimal.  Oh, and when you form that opinion express it here in a no if's and's or but's manner and see what happens!     Sorry, I had to put in the smiley... 

handloaders have found out that those weight bullets worked best for , lets say hunting.

As have target shooters, varmit shooters and all other shooters...

saying 'light for caliber" could be a fancy way of saying 'lighter then optimum" ?

Try telling JJ Hack that the 30 caliber 130 gr. Barnes is lighter then optimum for African plains game.  At least I think it was JJ that did that report, I'm not sure.  Whatever, that wouldn't be an accurate statement either.

Duck said that , for example a 220 grain .308 caliber bullet is " heavy for caliber" in a .308 but "optimum" in a .338 cartridge

Well, no he didn't, what he said was:

And the 220's that were heavy for 308 are about normal for 338's. (emphasis added)

Now I don't know how McWoody was defining normal, but it may have had something to do with what a casual observer would consider a frequently used or highly favored bullet weight in the .338WinMag.  He did not say it was optimal.  In my .338-06 I use a 180 gr. Nosler BT (no longer made) for deer sized animals and a 225 gr. NP if I were to hunt anything larger.

so the implication is, that its talking about bullet weight selection, for working up any given load for any given cartridge , and not really referring to the other things we have touched on here.

I'm not sure what you are saying here... But let me make a very general statement, If I can, based on the foregoing discussion.

The weight of a bullet that is said to be light or heavy for a given caliber is dependent upon what the speaker considers to be the standard weight for said caliber.

And, since SAMMI doesn't give a standard bullet weight for calibers that I know of, you are free to make that determination based on your own criteria!

I see that Ken posted while I was typing.  Thanks Ken, I was thinking about all the different reasons some bullet weights have become associated with certain cartridges and that is a point that had to be made, but I'm tired of typing!   

[necchi]

That's kinda neat,,How do ya get that many Highlighted quotes in one responce? Really I've always wondered how to do that..
Oh!,,,,
 

[Siskiyou]

It has been interesting to say the least!

AtlLaw & mcwoodduck a very good go at a moving target. 

[Scibaer]

richard,
 if i ticked you off, i apologize. you took a good deal of time to try and give me an explaination, of which i asked for.
you were kind enough to make that effort and i appreciate it.

[bobg]

I don't think you can tick off Richard. . He is to thick skinned for that.
                       bobg

[AtlLaw]

Naw Glen, for me, gettin ticked off is kinda like arguing.  I don't do either unless I'm getting paid for it!   

I did find something in the March/April issue of RifleShooter that may, with discussion, clear things up a little.  An article by Patrick Sweeney reviewing the new Stag Arms Model 8.  In it he states:

"...the 1:9 twist of the Model 8 happily shot all weights - from standard 55-grain FMJs to heavyweight bullets - into small clusters.  I've found some 1:9 barrels to be not so happy with 75 - 77-grain bullets, ..."  (emphisis added)

From those statements we can make 2 assumptions. 1 - The author believes that, in this or this type rifle, the 55gr. is "standard."  And, 2 - 75 -77 gr. bullets are "heavyweight" or heavy for caliber.  As assumption number 2 is based on the validity of assumption number 1, who determined that 55gr. was "standard" for the 5.56mm (.223)?

Remember what Ken said?

IMHO, bullet weights become "standard" or optimum because that is what the factory loaded when the cartridge was first introduced - same with military rounds.

The military, when deciding on the specs for the new rifle that would eventually replace the M14,  designated the parameters that the cartridge/bullet combination would have to fall into.  I'm sure their reasoning behind the choice is recorded somewhere.  That combination eventually became the 5.56x45 Nato cartridge which held a 55 gr. bullet.  And the 55gr. bullet remained the standard bullet weight throughout the VietNam era and beyond.

Since the weapon Mr. Sweeney was testing was a military style carbine, it stands to reason he would accept the military definition as what was the "standard" bullet weight.

Now let me muck things up a bit.  Oh, BTW, all this is verifiable should you care to research it.  I've long ago satisfied myself and do not have any cites.

I have 2 rifles chambered for the 5.56x45 Nato cartridge.  Both are AR-15's; an M16A1 clone and an A2.

I shoot nothing but 55gr. FMJ bullets in the A1.  It is my link to the old days.  To me, in that rifle, 75 -77 gr. bullets would be heavy for caliber and anything lighter would be light for caliber.

The A2 is my Hi-power match rifle.  The standard bullet for it is a 77 gr. match bullet that I shoot across the course.  I also may shoot an 80 grain bullet at the 600 yard line.  So, while this range of bullets may be standard for the use, they are still heavy for caliber based on the standard formed by the initial design and my own personal opinion.

Let's muck things up even more!  At some point the military decided the 55 gr. wasn't heavy enough for it's intended purpose.  So they came up with a new standard!  The 62 grain bullet!

Does the 55 gr. bullet immediately go from the standard weight to light for caliber?  No!  Why?  Because the standard bullet weight for any caliber is in the mind of the individual.  It is an opinion we form based on our own criteria and we don't have to, but we can, accept the opinion of others. 

Back when I was young and impressionable I was given an M16 and orderd to sally forth and do battle with the forces of evil.  The bullets that rifle shot were 55 gr.  I put the 55 gr. bullet to it's intended use many times and never had reason to complain about it's performance.  For those reasons and from that time foward, now and forever the 55 gr. bullet will be the "standard" for that caliber to me.

Another person, who served in the military when the 62 gr. bullet was king, may feel the same way about that weight.  To him the 55 gr. would be light for caliber.

With my mindset, although I shoot nothing lighter then 68 gr. bullets in my A2 I consider them and the 77 gr. Black Hills ammo I shoot my standard bullets and also heavy for the caliber.  BTW, I could go on about why long range paper punchers choose heavy for caliber bullets but I won't.

Another person out west who only shoots the 5.56 in the guise of it's civilian counterpart the .223 Rem. at PD's and GS's may consider the 40 gr. Blitz King his standard bullet.  He also may or may not consider it light for caliber based on his own criteria.  And you will not know what that criteria is unless you ask him.

Ya know, speaking of asking, what use do you intend to put all this personal opinion rambling to?

[Scibaer]

well the short answer is, for my own personal education. which in part is seperating the myth and old wives tales from fact or truth.
    i have been reloading for only about 2 years, so i'm new at it. i read, read and read, but i need the experience of others, that have been at it for some time to help me understand things i do yet have a grip on.  other stuff i can figure out, but some terms that get tossed around i dont quite get my head around without some guidance.
    i know that i dont ask my questions the right way at times. and i know that some of the questions i ask may not even really matter, but i want to know.
thats it in a nutshell..
glenn

[AtlLaw]

for my own personal education. ... i read, read and read,

Cool, that I understand completely!   

some terms that get tossed around i dont quite get my head around without some guidance.

Well, just remember Elliott's Three Axioms:
Trust no one;
Believe nothing;
Double check everything.

Try to absorb other people's opinions without trusting in them without question; read, read, read on the subject without believeing everything you read; perform your own 'speriments to check what others have said and written and then come to your own conclusions...

Or, just believe everything I say.   

 

[mcwoodduck]

When I said Normal I ment the bullet the cartridge started out with for mthe designers/ Factory.  Someone took the time to think I want to send a standard jackets bullet down the barrel at X speed to hunt this thing.  In the case of Big game rifles it was to hunt Animals in their class.  when standard big game loads did not works so well for hunters in Africa someone said I want to launch a .375 caliber bullet that (after making it) weighed 300 grains 2600 FPS to kill Cape Buffalo!  the case was then designed to hold X amount of propellant, in this case Cordite.  Someone later came by and said what if I shoot a 350 grain Bullet out of that same gun, will I have better stopping power and can I use it on larger game like Elephant?  And some one else said what if I shoot a 235 grain bullet at thinner skinned smaller animals,  and we have light, Normal, and heavy.  the light bullets are going to go faster, with the Normal being the standard, and the heavy are going to be longer slugs that go slower.  By going heavier or lighter you are trying to press that ctg into other areas.
Let's take Richards .308 Win.  He shoots a 150 or 165 grain bullet for deer sized game Figure 125 to 300 Pound animals.
If Richard's wife would not let him own more than one rifle (Just an example don't get defensive.    ) and friends of Richard call him up and say we are going to go hunt, Javilina Feb 2011.  A Javilina is about a 40 Pound pig like critter and Richard may want to get a 223 that would be perfect for the desert pig but his wifes rule may have him loading 125 grain bullets into his 308 to make it a medium game rifle.  Or that same friend calls him up and says, pack you hip boots we hunt Moose in September.  the Moose are similar to deer but are 500 to 1500 pound animals and the longer slug will penatrate deeper and depending on bullet construction may exit.  Well Michard may look to load 180 to 200 grain bullets for knock down \punch out of his 308, these would be heavy for caliber.  ( I guess that is a strange thing to say.  cause that 180 grain slug is heavy for 308Win but normal for the belted mags but I guess we should say heavy for the cartridge).  Again we are talking the standard Bullet design of a lead core and a copper alloy jacket.  When you get into the all Copper or Copper or Bronze alloys they are a lot longer of a bullet as Richard alluded to and change things.  Since tha copper is a lot lighter than the lead the bullet weighing 150 grains will be a lot longer and take up much more volume than the lead slug.  Where i would normally like 180 grain lead bullets I use the 150 all Copper and think of the 165 grain all copper as heavy for caliber out of my 308Win when I have to use a LEAD free round.

The using lighter bullets tends to get people to Neck down a case to a smaller diameter to use lighter bullets that have better SD than the light for calier bullets they were using, and now that bullet becomes the normal round.  but by no means Optimuim.  optimium is going to be matching the purpose of the bullet to the speed to the twist of the rifling so it will stabalize and get to the intended target, be it a target, game animal, or pest. 

Personally for most game I like to match the bullet construction, the weight, and the case to the game hunted in the conditions where I will be.  For example I like heavy round nose bullets for big game in the woods.  I like the Remington 180 grain Round nose 308's for deer up close as I think the round nose opens up and knocks the deer down while the pointed bullets just kind of zing through at short ranges, but that is what I think having shot deer with both.  Watched my uncles (one is 5 years older and the other 10) shoot deer with 130 grain bullets out of their .270 rifles that turned most of the meat into jelly and from then on did not like the light for caliber bullets, except for Varmints where splatter effect gives you points. 
In the field I like normal weight bullets in a Pointed soft point as I may have to shoot farther and the standard bullets fly better across fields.  If the deer runs a 100 yards he is usually still in the field and easy to find.  I have 2- 308 win Chambered rifles for deer.  One scoped and one open sighted along with 2 dozen + more rifles for other game, varmints or targets.  But I look at the gun closet as a golf bag and if a Sand wedge will work best, if I don't have one I will the next time we play that same course.

[necchi]

for my own personal education. which in part is seperating the myth and old wives tales from fact or truth.
   but i need the experience of others, that have been at it for some time to help me understand things i do yet have a grip on.  other stuff i can figure out,,,,

 ,,,but some terms that get tossed around i dont quite get my head around without some guidance.

Well said Glenn, that's it exactly! This has been/is a great topic. Thank you for putting the  forward.

And great answers from both these Gentlemen, both make agreeable points,,Thanks for the education.

[Dand]

pretty thorough discussion. I think these days there is a much much wider range of bullet weights available than there were prior to about 1990. This adds to the confusion, and the need for speaking of light or heavy for caliber. When I started loading in the 1970's and 80's, most 22 centerfires were loaded with 45 to 55 gr bullets - now look at the bullet offerings from 35?? to 80 or 90g. .243 was usually 85-105 yet now bullets a small as 55 are made. And so on. The 30 cal long had the greatest range from 100 to 220, and even some 250 gr but most people loaded 150-180 I'd say. The 338 has seen a great increase in bullet sizes as well.

I would add this phenomenon includes handgun rounds where the 357 mag now has 110 to 180 gr loads and the 44 mag is now commonly available in 180 to 300 and so with the 45 Colt. 

[Scibaer]

for me, this site is like an online college of guns, bullets and handloading.
i ask questions, because i know i get an education from the answers i get.
and i have lurked here for along time before signing in an say hi.
i have my personal core group of fellas, that i trust what they say, straight way. i know what they tell me , will be honest and as factual as one can be.
but, that core group has and is growing all the time, little by little.
those axiom's have thier place, sure. and the truth is, alot of what is spoken here is opinion, based on something, some times fact and some times, well .. bs.
and its up to the asker of the original question to sort that out, from the asnwers he gets, by the ppl that post them

i have read woodduck and atllaw's answers over a few times. one thing that keeps coming up is, that whoever deveploed the original load, selected a bullet of whatever weight, for some specific reason. its that reason that my focus is changing too
i thought that "light for caliber" carried more meaning then it seems to. its nothing more then a loose term, i think now.
but now, the idea of what wooduck explained in his last post " When I said Normal I ment the bullet the cartridge started out with for mthe designers/ Factory.  Someone took the time to think I want to send a standard jackets bullet down the barrel at X speed to hunt this thing." ... seems to me a more important topic, not that its any less intrinsic  or there is any hard and fast facts there either.
meaning, that someone at the factory just wanted to use x weight bullet and x speed.

[AtlLaw]

meaning, that someone at the factory just wanted to use x weight bullet and x speed.

EXACTLY!  <the clouds disappear, the heavens open up and the light of understanding floods down on our intrepid fellow reloader!> 

Probably the best known example of just what you said is the 87 grain bullet introduced with the 250-3000.  It was the heaviest weight they could use and still get the 3K velocity that was part of the name.  Or at least that's the story that's been around for many a year...    I don't know if it's true or not... makes sense though... I believe it... but it may be an urban legend... your choice.      

Be that as it may, I consider the 87 grain bullet light for that caliber.  I figger most would say that the 100 grain would be the quarter bores normal weight but I think that's light also.  My standard bullet weight for my Bob and 25-06 is the 117 grain because the SD = .253 which to my mind gives me a better chance of getting the penetration I want then does the 100 grain bullet at a SD of .216.

Hi-ebber, and day always be a hi-ebber, one of my rifle projects is a 250 Savage (to use the 250-3000's new name).  In it I plan to use the 100 grain bullet because of the restricted case capacity when compared to the Roberts.  For that same reason I would not hesitate to use the 120 bullet in the 25-06.

You see, even though the 25 caliber 100 gr. SD is way below my norm of .250, it has about the same SD as the 150 gr. .308 bullet at .226 and if you think I'm gonna say the 30 cal. 150 gr. bullet is to light for deer around this group you been smokin something!   

Now this is kinda humerous since the SD of the 100 gr. 243 Win cartridge is .242, a lot more then the 100 gr. 25 caliber which I consider fine for Bambi killing, whilst ever-body knows the 243 Win is marginal for deer!

Let me tell you how I came to that conclusion.  You see, ...  ...  ...  ... um, what were we talking about?

[AtlLaw]

Oh, BTW Scib,  thanks for giving me the oportunity to pontificate!     I do enjoy it so!   

[Scibaer]

well i'm glad i could help you work it out lol 

 when i work up a load, i try and use the heaviest bullet i can get for that caliber, its just makes sense to me to use a heavy bullet that will provide good accuracy and velocity. but im new to reloading, but not hunting or shooting, so i do have some experience of my own that lend me to believe that the heaviest weight bullet for that caliber is what i want to use.
 and when i read "heavy for caliber" i was thinking that there was something 'scientific' about that , and i stumbled on it without knowing why.
its interesting that you mentioned the .243 win.  my wife got me one for a gift, and i was not sure that it was enough gun for taking whitetails.
so , ofcourse i asked on here...and got many answers on both sides of the arguement. but that is where i first read about "light for caliber"

so, alot, well most of it comes down to opinion based on personal experience and the light or heavy for caliber means different things to different folks
, of whom prolly dont know anymore  about it then we have discussed here ..
 

[Siskiyou]

Scibaer
“ok, so does that suggest that there is an optimum weight bullet for any given caliber”

You’re Topic and the responses have brought up some interesting and well thought out responses.  My thoughts immediately turned to the militaries of the world.  Jumping forward from the cap and ball days to the spitzer’s bullet what have they done in bullet selection?  The period just before, during, post WWII era set the tone for today’s none magnum hunting rifles.  Like our society military standards changed in the early 1960’s to the spray and pray concept cartridge, and a different battle field.


It appears the waring nations that use the 8MM Mauser settled on a 198-grain bullet.


The Russian went to a 148-grain bullet in the 7.62.X54R.


The U.S. 30 Govt. 1906 had a 150-grain FMJ loaded to 2700 feet per second.  The later Garand operating system was designed to work at that level.  The 150-Grain FMJ has an estimated SD of .226.  The long range machinegun round had a 172-grain bullet.  A sporting .308, 165-grain bullet has a SD of approximately .248.


The Japanese went to the FMJ 7.7 round because the lighter 6.5 did not provide the penetration they wanted against heavy targets.  They used a 175-grain bullet. It appears the Japanese used the British .303 round as a pattern, enlarging it slightly and making it rimless.  The used a 175-grain bullet.


The British settled on a FMJ 174-grain bullet in their .303 British in its later years.  In the sporting world the Japanese 7.7 and the British 303 take the same .311/312 bullets.


Hornady sells a couple of 174-grain bullets, a 174-grain FMJ with an S.D.255, I have no idea how close this is the military 174-grain FMJ.


I must not leave out the Swede 6.5X55.  When they went to a spitzer’s bullet they settled on a 139 grain bullet.  It is amazing that the S.D. comes in around .287.


I believe the militaries of the world looked for, and researched bullets to achieve the optimum results within a certain criteria.  The ability of the rifleman to deal with the recoil was a motivating factor for the U.S. to select a balanced .30 U.S. round at 2700 feet per second with a 150-grain bullet out of an infantry rifle.  Pre-WWII the British wanted to modernize their infantry round but the War and supply needs locked them into the .303 round.


I liked AtlLaw  setting the SD rail at +/- .248.  


The military never used the .243 as far as I know but I got for the 100 and 105 grain bullets for deer, 80-grains for varmints.  


Over the last fifty some years I have shot a lot of deer with the .270 Winchester.  I currently load a shoot three rifles in .270 Winchester.  As a kid I was impressed with velocity not taking into consideration of the moral of the tortoise and the hare story.  Reflecting back on the U.S. Military when they wanted a long range .30 Caliber machine gun bullet they went to a heavier bullet at the same increasing velocity.  


I killed a bunch of deer with 130-grain bullets but I prefer the 140 and 150-grain bullets because they retain long range velocity and normally exit the deer.  The 130-grain bullets normally fall short of the magic .250 and the 140 and 150-grain exceed .250 SD.


The 160-grain bullet in the 7 Remington Magnum fits the plus .250SD criteria and that is what I normally carry.  A couple of times I have carried 175-grain loads because they are very accurate in my rifle.  Those heavy weight bullets might not be the best with smaller case 7MM rifles.


Do I put the 30-30 Winchester in a different category, because I have a good supply of 150-grain Remington C-L, and Federal ammunition?    The 150-grain bullets designed for the 30-30 have a SD of approximately .226 which is starting to fall towards the short end of the stick.  The 150-grain bullet in the 30-30 has taken a lot of deer.  It has been my experience that the bullets are recovered in the deer.


The argument can be made that if the bullet it recovered from a deer it did its job.  I cannot disagree, but I prefer the 170-grain bullet in the 30-30 because they tend to penetrate deeper, and exit in many cases.


I am stepping over the technology bar in this case but I hoped to take a deer in the past season using the 160-grain Flex-tip bullet in the 30-30.  It falls short of the magic SD.250.


I prefer the 165-grain bullet in the .300 Savage and 30-06.  Having written that again this past season I watch my hunting partner shoot a buck just behind the shoulder using a WW factory150-grain bullet.  Blood and gore spray out the off side for better than three feet.


I am a little on the selfish side. This winter I load a bunch of 30-06 cases for the SIL.  I load twenty with 165-grain bullets, but wanting to maintain my supply of that optimum size for deer, I loaded another forty with 150-grain bullets.


Right now I have a bunch of .303 British cases in the tumbler.  I kind of decided my course of action a few months ago when I ordered two boxes of 174-grain Hornady Roundnose bullets with a SD .255.  This had been my best shooting bullet in my Jungle Carbine up to that time.  Recently I tested a number of different powder charges with the 174-grain bullet, and the 150-grain Sierra and Hornady bullets at the range.


The accuracy of the Hornady 150-grain .303 bullet looks promising.  It has a SD.220 which is less than the 150-grain bullet in the 30-30.  I can see getting on thin ice with this bullet because it offers flatter trajectory and higher retained velocity.


I consider this Jungle Carbine a short range, nasty weather rifle when iron sights rules the day.  Picking up a track of a deer moving from the high country in fresh snow and going after the critter that made the track.  Experience tells me that most shots are rather close under these conditions.  Thicket brush and dog hair thickets of timber reproduction rule the day.


The only game I have taken with the 8MM Mauser was this bear.





If I recall correctly the bullet was 172 or 174 grains which as a SD.233 what is on the low side of the magic .250SD I prefer.  


The hunter with more than one rifle or load suffers a conflict.  There have been those days that I have actually pickup a rifle other than a .270 Winchester to hunt deer.  In the long past my hunting partners had no doubt what I was carrying, but now days they need to check.  All the calibers I have mention will take a deer or a black bear.  

[mcwoodduck]

I often wonder if the diff between the European and English / American loadings are the diff. between the metric and imperial systems.
an even number of grams will come out to an odd number of grains.  Looking at the rifles and ctgs that fought in WW1 all are about even with the other.  Shooting a 264 - 232 diameter bullet at 2,400 to 3,000 fps with 130 to 190 grains and capible of shooting at targets 1700 yards or closer.  not sure if it was the 1891 French Label that set the standard and everyone else mae what they adopted because the French had it first and they were trying ot keep up with the jones'

But someone to talk to is Stimpy on this subject of why this projectile, this case, and this propellant.  He makes all kinds of wild cats.  May be a good insite into why certain ctgs are devoloped.  There is the whole pressure issue as well.