Author Topic: pressurer differences with bullet dia. (Read 1138 times)

zacharoo · « **on:** August 26, 2008, 03:54:31 PM »

What is the pressure difference with a .454 dia. and a .452 dia. bullet with the same powder charge through a .452 dia, bore in a ruger 45 blackhawk. Is it safe to use the same data with both hard cast bullets?
Zacharoo

LaOtto222 · « **Reply #1 on:** August 26, 2008, 04:37:44 PM »

You have not said what your present load is. Are you loafing along at 700 fps or are you pushing the limit with 1000 fps loads? Hard cast bullets are easier to push down the barrel than jacketed bullets - less friction. Is there a pressure difference between two hard cast bullets with .002" diameter difference? Not a whole lot, but some, I suspect. If you are in the 700 - 800 range, I would not worry about it. I do not have pressure testing equipment to be sure. If you developed a load using .452" bullets and are pushing the limit; back off a little and try the larger diameter bullets and see if you get the same velocity using a chronograph, to see if you are pushing the pressure limits of your 45 Long Colt Blackhawk. If you get the same velocity, then do not increase your powder charge. Decrease it if the velocity is higher. Under no circumstances should you get velocities over published standards, i.e. If your load book calls for 7 grains of powder X for 800 fps using the same style bullets, and you are getting 900 fps -you are developing higher pressures. Let your chronograph be your guide. Lyman's reloading book is an excellent source for load data for cast bullets. I have the 48th edition, but the 49th is available now. Good Luck and Good Shooting

zacharoo · « **Reply #2 on:** August 26, 2008, 06:21:21 PM »

I am loading 6.7 grains of bullseye for about 900fps. Out of a ruger 7 1/2 barrel. With .452 and I haven't shot any of the .454 yet. I am asking expert advise first to be safe.
Zacharoo I NEED ADVISE

zacharoo · « **Reply #3 on:** August 26, 2008, 06:24:43 PM »

Going by data don't have an instament to measure speed. Wish I did
Zacharoo

stimpylu32 · « **Reply #4 on:** August 26, 2008, 07:26:33 PM »

In this case it will be more of what weight bullet your using than what dia. bullet , just make sure your data fits with the bullet weight your loading , loading a 250g bullet with 180g data can be very bad no matter the bullet dia.

Both being the same , there is no reason to worry here , you may have a small amount of leading at the forcing cone from the larger bullets though .

stimpy

zacharoo · « **Reply #5 on:** August 27, 2008, 03:05:32 AM »

Bullet eight is 200 grain SWC. Sure ly thank you for the advice. I have only been reloading for that 45 for about a year and don't know much except it is a great bullet. Thanks again The data is from a reloading manual that I know for sure.
Zacharoo

zacharoo · « **Reply #6 on:** August 27, 2008, 03:07:58 AM »

Stimpy. Are you a miner. I worked in the salt mines in Louisiana for 32 years as a mechanic. Saint Barbra watched over me all the time.
Zacharoo

stimpylu32 · « **Reply #7 on:** August 27, 2008, 04:18:08 AM »

zacharoo

Nope , I'm a Sparky - I drag wires around to LIGHT your world .

Do most of my work in Oil and Petro Chem. plants as well as some pipeline pumping station's .

stimpy

zacharoo · « **Reply #8 on:** August 27, 2008, 05:14:30 AM »

Well saw the hardhat and radio and thought you were well good luck and thanks for the info.
Zacharoo

Graybeard · « **Reply #9 on:** August 27, 2008, 08:54:01 AM »

There really is no way to answer your question regarding the pressure. Will there be more with a .454" than a .452"? Yes if of same composition but how much is impossible to know without doing lab testing. If your bullets are jacketed pressures would increase the most then if very hard cast next most with softer cast showing less difference.

In your bore of .452" or there about the .454" shouldn't run pressures up all that much even with hard cast bullets. You might want to be careful about absolute book max loads and for sure not go over book max. Unless you are pushing over book max I'd personally not worry about it.

zacharoo · « **Reply #10 on:** August 27, 2008, 02:05:01 PM »

They are hard lead and I am using 6.7 grains of bullseye. Would that be OKJ!!!
Zacharoo

LaOtto222 · « **Reply #11 on:** August 28, 2008, 01:02:07 AM »

I am not flaming you here. I know you would like answers and I think everyone that has responded are trying the best they can. If you are looking for a "it's OK, it will not make a difference", or "do not do that" you are looking to the wrong people for an answer. For the most part the folks on this forum preach safe hand loading practices. We do not want some one to get hurt. Every gun, every different load (even just a change in bullets) will give you a difference in pressure. No one knows how much difference it will make. If they say they do, they are full of it with out pressure testing equipment. If you do not have pressure testing equipment, the next best thing is a chronograph, with out that, you are "flying by the seat of your pants". You are just plain guessing. No one that is responsible is going to tell you it is is OK. As advised by me and several others here, you are just going to have to try it and decide on your own if it is safe. More than likely it will not make a difference as advised basically by Bill, Richard and by me, but no one is going to come out and tell you it is OK to do, that would irresponsible. I advised cutting back a little on your charge just to be safe and work your way backup, if you think there is a possibility of getting an over pressure situation, and there is a possibility. I think it is a slim possibility, but I or anyone else just do not know for sure. With out something to measure by, you are just plain guessing and that is what any one else could do. When it comes to hand loading there are some things that you have to decide on your own, this is one of those.

Mikey · « **Reply #12 on:** August 28, 2008, 02:21:57 AM »

OK, here's another question in the same vein regarding pressure differences or increases. Let's say you are shooting the same bullet over the same powder charge but need to seat the bullet deeper for one revolver than for another.

Let's say for example you are shooting a`44 mag with a 290 -300 gn cast swc over 19.5 of H110/WW296. Let's say you seat the bullet and crimp on the crimp groove just beneath the front leading band for one revolver but find you need to seat more deeply for another revolver - seat to crimp just over the front leading band. Some powders like the H110/WW296 should not have any room twixt the bottom of the bullet and the powder charge however, what sort of pressure increases might one see when comparing the two loads???

Thanks. Mikey.

zacharoo · « **Reply #13 on:** August 28, 2008, 03:11:24 AM »

Sorry to cause trouble. I was just trying to find out something i was not sure of. I didn't mean to offend or flare any tempers. Thanks!
Zacharoo

stimpylu32 · « **Reply #14 on:** August 28, 2008, 04:05:53 AM »

zacharoo

You are not causing trouble and you have not offended anyone , will you have a pressure increase ? yes ,will it make that much of a difference ? not likely -- Unless your close to or at MAX load .

Guns and Ammo TV did a test were they shot a 45LC down a shot barrel with the choke still in the barrel were it had to swedge the bullet down quite a bit and no adverse affects were seen .

Mikey
Yes you will have a pressure increase by seating the bullet deeper , it will also change the pressure curve but without the proper testing equiptment no one can tell you just how much.

stimpy

LaOtto222 · « **Reply #15 on:** August 28, 2008, 06:42:29 AM »

zacharoo - I am not upset at all. I just want you to understand why no one was answering question directly. I know it can be frustrating. I asked about have a barrel house chamber one of their barrels or buy it and have a local gunsmith do it. There is no good answer for this and all I got was the sound of crickets chirping. I was just looking for their oppions, knowing full well it was up to me to make the decision what to do and I would be responsible - but no response. I understood and did not feel I offended anyone or upset any one. Good Luck and Good Shooting

Mikey - +1 on what Stimpy said.

zacharoo · « **Reply #16 on:** August 28, 2008, 11:40:10 AM »

THANKS GUYS !!!!
Zacharoo

wncchester · « **Reply #17 on:** August 28, 2008, 11:55:05 AM »

" Is it safe to use the same data with both hard cast bullets? "

Yes.

LaOtto222 · « **Reply #18 on:** August 29, 2008, 01:58:16 AM »

wncchester - I have a few hundred dollars saved up for a 204 barrel. I would really like to to have some pressure testing equipment so I would forgo the new barrel for a while if I could get reliable pressure testing equipment. If it is not too expensive, I would wait until I saved up some more. How much did you pay for the equipment that you have? And where did you get it? Did you do your testing in a revolver? Was it a BlackHawk? Or did you use a pressure barrel? If you used a revolver, where you put the strain gauges (or did you bore holes for transducer?), where they on the cylinder or did you place them on the barrel? Did you test on both? I know I have a lot of questions, but I really would like to have some equipment to measure pressure with, it would clear up a lot of questions for me. Just a few more - What was the brinell hardness of the before bullet (.452) and the after bullet (.454)? And finally what was the pressure of the .452 bullet and how much did it go up for the .454 bullet? Did you use the exact same load as Zackaroo (6.7 grains of bullseye) or did you test at maximum pressure levels and what powder did you use? Were the results you got comparable to any of the load data found in any of the load manuals? I mean were the powder levels and fps at maximum pressure comparable? Just one more - I was curious if you tested more than Bullseye and if you did, what were your results? I am really sorry for all the questions, hopefully you will have all of the data not too far away so you can answer them with out spending a lot of time at it. I know it takes considerable time to do all of the testing so I would hope you would take just a few minutes to answer them.

AtlLaw · « **Reply #19 on:** August 29, 2008, 04:05:08 AM »

Quote from: LaOtto222 on August 29, 2008, 01:58:16 AM

I would really like to to have some pressure testing equipment so I would forgo the new barrel for a while if I could get reliable pressure testing equipment. If it is not too expensive, I would wait until I saved up some more. ... <major snippage>

I started reading this and immediately started thinking "who is this yo y ..."

then I glanced over at the author...

What the heck!?

So I read the post you were responding to... $:-\$

You just couldn't let it go could you?

LaOtto222 · « **Reply #20 on:** August 29, 2008, 06:16:10 AM »

AtlLaw - I assumed that he was not irresponsible by just making a guess what may be safe or not. So I figured he must have derived his advice from a reliable source (pressure readings) using the same components/gun that zacharoo used, I just want to be sure how he did his testing. I have had a want for affordable pressure testing equipment, I think I remember you saying that too. I wondered if I could afford to buy the same equipment he was using, maybe he has a source that I could afford, that i was not aware of. You do not think I could have made a bad assumption, do you?

AtlLaw · « **Reply #21 on:** August 29, 2008, 06:20:31 AM »

Quote from: LaOtto222 on August 29, 2008, 06:16:10 AM

You do not think I could have made a bad assumption, do you?

Ooooooooh no!... you're not going to get ME in the middle of this!

Maplicito · « **Reply #22 on:** August 29, 2008, 06:41:07 AM »

Affordable pressure testing equipment? I want in! Oh wait... you're only stirring the pot, aren't you? Well, I still want in

stimpylu32 · « **Reply #23 on:** August 29, 2008, 10:20:54 AM »

Quote from: wncchester on August 28, 2008, 11:55:05 AM

" Is it safe to use the same data with both hard cast bullets? "

Yes.

As much as it pains me , I do tend to agree with this statement . WHY ? because in just about all the data that I can find for cast bullets it does not spec which dia. bullet to use .

In most rounds you will find that the 45 auto will have a bore for a .451 or .452 dia. bullet and the 45LC will be a .453 or a .454 BUT NOT ALWAYS .

That being said , to use a large dia. bullet in a barrel with a small dia. bore will increase pressures , how much is anyones guess with out the proper test inst. but on the other side of the coin , a small dia. bullet in a large dia. bore will drop the pressures .

As most data does not spec bullet dia. , to say that the same data could be used would be a valid statement because the bullet or powders companies would have to have taken that into account .

stimpy

zacharoo · « **Reply #24 on:** August 29, 2008, 11:26:48 AM »

If I knew I would have started this I would have made fishing weights with those bullets!!!!!!!!!!
Zacharoo

stimpylu32 · « **Reply #25 on:** August 29, 2008, 12:01:24 PM »

Quote from: zacharoo on August 29, 2008, 11:26:48 AM

If I knew I would have started this I would have made fishing weights with those bullets!!!!!!!!!!
Zacharoo

Why ? The crossing of info and ideas are what makes this place and this country what they are . We may not always agree on everything but we all can learn from each other and thats what we are here for !

And if your going to melt them , you might as well re-cast them to .452 .

stimpy

LaOtto222 · « **Reply #26 on:** August 29, 2008, 02:06:02 PM »

zacharoo - I agree too. I do not recall anyone saying it was unsafe. It probably will not make much difference, if any, if the bullets are .452 or .454. I said as much above. To me, there are just too many factors involved to say simply yes or no. I do like the way Stimpy answered, he gave reasoning that I could live with. I may have went in a wrong direction in an attempt to draw out how the "yes" came about. I should have been more direct. I really do not want to assassinate anyone's character (every one has an opinion), I just would like to see complete answers. I like to get into "discussions", to me it part of the interchange of ideas.

I have been reloading for many years. I have been lucky enough to never have a gun blow up or even have a part that needed replaced. I know there are people that have been shooting and reloading for a long time and not so long that have had bad experiences. Some times through no fault of their own (bad Karma; bad luck), poor reloading practices, carelessness and some times because they took a chance or three. I do not want any one to have an experience like that if it can be helped.

BTW if anyone knows of a cheap (something I could afford) way of measuring cartridge pressure with out ruining the gun by boring a hole in it and some thing like a tape on or glued on strain gage, that could be used over and over, I would be very interested - I am serious about that.

zacharoo · « **Reply #27 on:** August 30, 2008, 02:54:23 AM »

Thanks stimpy! I ran about 50 an every thing looks ok. mNo pressure signs so far. I will just watch close where I sight them in . They shoot low and nort to much leading at the cone of barrel. No shaving or like that. Primers are tight and no bulge or cratering. Will stay with a low charge and looks OK. I am more worried about the hurricane than shooting. But GOD WILL PROTECT US IF WE HELP OURSELVES >

Mikey · « **Reply #28 on:** August 30, 2008, 12:12:17 PM »

Zacharoo: The load you're talking about, 45 Colt - 6.7 of Unique under a 200 gn slug is no killer for a Ruger Blackhawk and is well within pressure ranges for even heavier bullets.

If you are wondering about the effects of pressure caused by 'large for the bore' slugs you should be able to tell the difference without harming yourself or the revolver. If your loads run at higher pressure due to larger bullet dia. they should hit lower than lower pressure/smaller bullet dia. loads that probably travel slower, given the same bullet and powder.

Shoot some and see. The only thing a slug that is larger than what the bore calls for will really do when you are talking about .002" is give you crummy accuracy.

I believe you can most often use the same charge for cast and jacketed. I use the same charges in most of my semi autos regardless and enjoy good accuracy and long case life. Mikey.

wncchester · « **Reply #29 on:** October 29, 2008, 04:14:38 PM »

" How much did you pay for the equipment that you have? And where did you get it? "

I just returned to find this question. The answer is:

Nope, none of the above. As you hoped not, I was "irresponsible" and just pulled it outta the air. Well, several decades of reloading experience behind me sorta helped.

It's really not rocket science. Consider that the Ruger is very strong, the load is light and (soft) lead bullets (all bullets for that matter) become bore diameter after they have moved their own full length in the bore, and that occurs well before peak pressure is reached.

But, Bill's, Mickey's and Stimpy's observations and Zacaroo's experience sustain me. Enough said about it.