Re-opening old smelly can of worms

[Haywire Haywood]

I know this has been hashed and rehashed, but I forget the outcome.  This might be something that Fred could answer. 

How does the 500 S&W compare to 45-70 ruger loads when it comes to bolt thrust, and if the 500 is more, can this be used to extract that Ruger loads are ok in the Handi.

... and further... the 45-90 smokeless loads listed in Lyman #48 are getting Ruger velocities with marlin pressures... If we determine that the Handi can take ruger pressures, could you bump the '90 up to Ruger pressures safely, it has the same head diameter after all.  I seriously doubt it but I had to throw it out for discussion. 

I seem to recall that bolt thrust has a lot to do with case pressure and case rim diameter.  The recoil calculators that I have seen use bullet weight and velocity.  It seems that the two would be linked somehow, since increased bullet weight or velocity increases recoil, that it would also increase bolt thrust.  If that were true, then the 45-90 loads might have ruger level bolt thrust while at the same time not exceeding Marlin pressures.  I know my shoulder knows it when I launch a 400gr cast bullet at 1900fps.

Ian

 

[quickdtoo]

NFG has pushed loads well above Lyman's Ruger loads with IMR4198 using 300gr and 400gr bullets in his BC, of course that's just his  rifle and he worked his way up and had to increase rifle weight to about 12lbs to do it!!

Tim

http://www.graybeardoutdoors.com/smf/index.php/topic,94841.0.html

http://www.shootersforum.com/showthread.htm?t=30527

[Haywire Haywood]

Now there was a lot of reading there Tim... links and cross links... took me over an hour.. NFG certainly has a set of brass ones doesn't he LOL

I did some side-by-side comparisons between 45-70 max Ruger loads and Lyman's 45-90 smokeless loads and the '90 loads go about 4-5gr of powder more than the Ruger data.  I was using RE-7, which is faster than 4198.. I think I'll play around with some 4895 or 4064 and see what that gets me.

Ian

[quickdtoo]

Ian,

Here's a bunch of smokeless .45-90 data compliments of Montanan, you probably have it already, but just in case you don't.

Tim

http://img.photobucket.com/albums/v386/quickdtoo/45-90smokeless.jpg

http://img.photobucket.com/albums/v386/quickdtoo/45-90smokeless2.jpg

[Haywire Haywood]

Yep, i have those printed out, but they are trapdoor loads.  I was looking for stouter offerings.

thanks Tim.

[Fred M]

Ian.
To interpolate pressure from one cartridge and apply it to another is bad news, with very questionable results.

If equal pressures are generated in the 500Mag and the 45-70 the 45-70 will have a lesser bolt thrust. Simply because the thrust area is smalller. So if the 500 Mag at 60K can be contained in a rifle, then a cartridge in a 45-70 can also be loaded to the same pressure and contained in the same gun. Providing the brass of the cartridge is of equal integrity and quality, and therein lies the trouble.

Cases are designed to suit certain requirements and SAMMI specs. So the 500Mag and the 45-70 are not designed with the same specs. Comparison and interpolation should not be used with these two cartridges.

Bolt thrust is measured by the inside diameter of the case at the pressure ring which is about a 1/4 above the base in most cartridges Thrust equals ID r-sqx3.14xp.

This pressure is the distributed over the base of the case including some part of the rim. This will reduce the actual thrust on the standing breech. I don't know how much of the rim can be used since the rim is not supported forward during firing.
In any event the small amount of rim area would not sustantionally reduce thrust.

[Haywire Haywood]

Providing the brass of the cartridge is of equal integrity and quality, and therein lies the trouble.

Hmm.. I hadn't concidered that. So the quality/design of the brass has an impact.  Looking back at my manuals, Ruger level cast loads max out at 40k CUP as opposed to jacketed loads which develop 50k CUP.  Since I only shoot cast, would it be fair to say that since the frame can take 60k 500 S&W jacketed loads, that a 40k cast load would be acceptable, even concidering the effect of the brass involved?  ----Just figured out I was comparing apples and oranges.. 40k CUP vs 60k PSI.. can't find an online converter on a quick search. Seems I recall 50kCUP = 58K PSI... izzat close? if so, that would mean that 40K CUP would be 46.4K PSI.

Just trying to get this un-crooked in my mind.. Assuming the same brass, You get the same thrust on the breech from a 300gr loaded to 40k as a 400gr loaded to 40k.  Doesn't seem logical, but I'm not a physics guy afterall.  It would also seem logical (to me) that a fast powder would build up a higher pressure faster than a slower powder that "uses" more of the barrel.  The pressure curve would be more gentle. The data in my manuals seems to be saying that. A 17.5gr load of unique under a 385gr LRN produces 38,500CUP and 1411fps while a 60gr load of 3031 produces 33k CUP and 2117fps.

sorry about the ramble.. thinking as I'm typing...,
Ian

[Fred M]

A 17.5gr load of unique under a 385gr LRN produces 38,500CUP and 1411fps while a 60gr load of 3031 produces 33k CUP and 2117fps.

The energy of powder is controled by a retartent coating. While both powders produce 38.5 kcup. The duration of the burn is totally different. Unique will die out shortly after being ignited. While 3031 will perhaps still burn at the end of the barrel and is keeping up the pressure, hence the higher velocity.

This why slow burning powders produce higher velocities in most applications, but not always. The reason for that is the ratio beween case capacity and bore volume.
Its called expansion ratio.

In a big bores like a 45cal the powder needs to be faster than in a small bore. It is best when you use the powders recommended by the powder manufactures, they figure out the best expansion ratios with the lowest chamber pressures and the highest velocities.

There are no accurate conversions to convert CUP to PSI. There is one that is some how usable in the midle of the range. I talked to the Hodgdon lab man and he said not to use it. The reason Hodgdon still uses CUP is their inventory of expensive universal receivers and barrels. All their new pressure testing equipment is in PSI.

The 375 Winchester is SAMMI rated at 64.3 KPSI, but I don't think I would want to load a Handi to that pressure. Non of the Handloads are loaded that high, that is not to say somebody would load up a 38-55 to that pressure since both cases are almost identical.

The saying goes if you want more power get a bigger case and a bigger rifle. 458 Win Mag or 375 H&H comes to mind.

[NFG]

Oh, Yeah.  I keep the brass ones polished up real nice and pretty, just in case I have to use them again some day.

Nothing I did while I was working up those loads was outside what I've learned about this thing in the past half century of burning powder. 

In other words..."I don't take chances". 

I use "Load from a Disk" and all the data in the published manuals before I start testing to get a starting point, then work up slowly.

All the data I deveveloped can be checked out using "Load Disk".  It is also, as Tim said, ONLY FOR MY RIFLE AND THE COMPONENTS I USED.

Remember, case brass has a specific SAMMI pressure range, just like a specific cartridge.  Case capacity can change just by changing seating depth.  There are many ways to increase velocity without going beyond SAMMI spec pressures, you just have to know and understand how to use the data.

If you want to play on this highway and not get hit, you have to do a lot of home work.  Get the data from the professionals at the powder and bullet making companies, NOT on some forum.  Forums are great for Koffee-Klatches,  but you don't know who is doing the talking for the most part, or what their actual knowledge base consists of.  I'm too paranoid to believe much of what is printed and even less of what is said.   People have needs, just go to any bar, get a beer and sit down to listen.  Forums are no different.

I miked the cases to be sure I was not getting beyond safe practices.  I measured the amount of case stretch and the amount trimmed and kept a running total.  I looked for insipient head separation which is a good indicator of a problem. I kept a total of the number of times each case was loaded.  I measured the case rim and watched the primer pockets. 

And I did many more things I can't even describe, that I've learned through experience and do without thinking almost.  I reloaded one case 5 times at the high velocity and it was still going strong at the last loading.  Some of the wildcats I've played with would die after the second reload.  I usually limit my larger caliber cases to 5 reloads then toss them.  Brass is cheap.  I also make sure my diesare set to resize the case to fit the chamber, so the brass doesn't get worked too much

I've been know to take some very scary chances, all calculated, and I don't any more, but I don't do CHANCE with my reloads.

I guarantee if you get magnumitis with a break open rifle you will lock it up when you get beyond the limitations of brass case, all the BS about KPSI and what one cartridge will do compared to another, aside. 

Common old 1120 CR steel has a minimun of over 40,000 psi, that's pounds per square inch, I can't remember exactly in which modus, and good 4130-4140 barrel steel is closer to 50,000 psi.  Break out your calculator and figure out just what the area of a 45-70 case is, then you can calculate how thick the chamber walls need to be to contain the pressure generated.  It wil open your eyes.  Most magnums are loaded to about 65,000 psi so how thick does the walls have to be?  I will let the engineers do the walking.

There are lots of considerations to think about when you want to go beyond the published data, mess with wildcats, go where few have ventured, but it's lots of fun.

By the By Fred, my books list the 375 Win at 52,000 CUP at least all the one's that list pressures.  That Win 94 Fatboy handles the 375 Win, I think a Handi-Rifle would, not to get any arguments started, you have to do what you think is best.

Anyway...Enjoy  NFG

[Haywire Haywood]

Did a little more reading and the Hornady manual says that their Marlin loads are held to 40k CUP.  H&R's official statement is that the Handi is rated for Marlin loads.  All the data I have (that use CUP) has Ruger level cast loads at well under 40k CUP, so I don't feel like I'm pushing the limits by loading my cast bullets out to Ruger levels.  That's the 45-70.  The 45-90 does more with less pressure but I don't have enough smokeless info to really feel comfortable experimenting.

NFG, do me a favor.  What does "load with a disk" say about 60gr of 3031 under a 325gr lead bullet in the 45-90 (32" barrel)?  It's 33K CUP in the 45-70 and max load listed in the Ruger data.

thanks,
Ian

[Grizz_]

Did a little more reading and the Hornady manual says that their Marlin loads are held to 40k CUP.  H&R's official statement is that the Handi is rated for Marlin loads.  All the data I have (that use CUP) has Ruger level cast loads at well under 40k CUP, so I don't feel like I'm pushing the limits by loading my cast bullets out to Ruger levels.  That's the 45-70.  The 45-90 does more with less pressure but I don't have enough smokeless info to really feel comfortable experimenting.

NFG, do me a favor.  What does "load with a disk" say about 60gr of 3031 under a 325gr lead bullet in the 45-90 (32" barrel)?  It's 33K CUP in the 45-70 and max load listed in the Ruger data.

thanks,
Ian

I've gone round and round with this also, and here's a CAUTION for you concerning the Ruger loads you are looking at: COL is MUCH DIFFERENT for the Ruger cast loads than for the Marlin loads. This is because the bullets are seated out for the Ruger and the case capacity is completely different. This is a HUGE consideration, and the reason we can't use the Ruger data for a direct comparison. 2 different COLs is bananas and grapefruits.

Hope this is helpful,

Grizz

[NFG]

Manuals are for reference only, the information isn't cut in stone and it is developed, many times, using a universal receiver and closely spec'ed barrels, so the information is for THAT specific set of parameters.

"Load from a Disk" doesn't work like you and I want it to.  It has a range of bullets, powders, etc and gives a range of information using the information you provide starting with the case and working up.  It listed only one 325 gr lead bullet and that is the one I used.  The powders are listed in a range also and list several with similar range of burning characteristics, like 3031, RL7, H322, AA2230, etc., all lumped into one group and slower or faster powders lumped similarly.  It gives the pressures for the group...NOt...one single powder, so when you are working up a load you can start with the first powder of the group and work you way through to find which powder the rifle likes best, just like changing bullets, primers, and seating depth to find the most accurate or the highest velocity, depending on what you are looking for.

All that being said as a caveat..."Let the reloader beware".

What LD did come up with for the 325 gr RCBS bullet is:  2.88" LOA and 77.343 case capacity:

58 gr 3031, 1952 f/s, 28177 CUP, 75% load density.

61.9 gr 3031, 2084 f/s, 32094 CUP, 80% load density.

Extrapolating and interpolating for a 60 gr load

60 gr 3031, 2020 f/s, 30135 CUP, 77.5% load density, 2.88" LOA, 0.340 seating depth, 77.343 net case capacity gr of H20. 

Case capacity can be varied up or down by changing the seating depth.  Reducing the case capacity will increase the pressure and sometimes the velocity as well...BU... most of the time that reduction will also reduce the velocity, again not cast in concrete.

A 0.012" increase or decrease in seating depth change from the original 2.88" gives the following:

Reduce the OAL to 2.76, seat depth 0.460" and LD comes up with no 3031 and  H4198 as the first available powder, still 75% load density at 54.3 gr, 2118 f/s at 34418 CUP.  75% load density is the lowest load density LD goes for this case.

Increase the OAL to 3.00" increases the case capacity to 82.33 gr H2O, reduces the seating depth to 0.220 and changes the load parameters to 61.7 gr 3031, 2045 f/s at 29548 CUP.  Actually...going to BLC-2, 61.7 gr increases the velocity to 2139 f/s at 32446 CUP, still at 75% load density.  Quite a nice jump in velocity, wouldn't you say?  I love my LOAD DISK.  You should turn loose of your purse and spend the 75 bucks or so for a copy.  It will do you good, I guarantee.

Looks like they match fairly well within the normal range of pressures.  You will be receiving the bill for professional services rendered in a few days.  Please remit promptly.

Wish I had this program when I first started out.  Would have saved me boo-koo-bucks in components and a couple of receivers.

You have to remember, for the most part, everyone in this business is selling some thing and anything having to do with money is full of politicians and you know what they do.  AND...EVERYONE has to protect their egos and favorite toy...no matter if it is a rifle, car, truck, wife and so on.  EXCEPT me, of course.

This information should give you a new perspective on what you can and can't do and where the "sectets" are hidden.

Enjoy  NEF

[Haywire Haywood]

Thanks for the info NFG, and the warning Grizz.  More stuff to take into consideration.  In this instance, my 325 loaded to the crimp groove is .317 into the case for an OAL of ~2.85.

thanks,
Ian