What's up with this 45-70 loading data?

[Autorim]

I have a copy of Hodgdon's 2008 Annual Loading Manual and it lists the loads for the 45-70 Government in
( Modern Rifles ) as follows for the 300 grain Sierra HP and IMR 4198.

54.0 grains for 2253 fps and 31,800 CUP and 58.5 grains for 2450 fps and 2450 fps at 43,000 CUP

My Sierra Manual for the Ruger No. 1 and No. 3 lists a maximum load at 51.8 grains of IMR 4198 for 2150 fps.

My max. hunting load for this bullet is 51.0 grains of IMR 4198 and the recoil is quite substantial. Personally, I don't want to try any heavier loads. This load chronos 2100 fps in my No. 1 and generates over 3000 foot pounds of energy.

Has anyone used this bullet with 58.5 grains of IMR 4198? How is your shoulder?

Autorim

[NFG]

G

[Lone Star]

There is little convention regarding maximum loads in .45-70 rifles.  In CUP:

Data.........Trapdoor.....Marlin........Ruger
Lyman........18,000.....28,000.......40,000
Speer.........21,000.....28,000.......35,000
Hornady.....25,000.....40,000........50,000
Hodgdon....28,000.....40,000........50,000

As is clear, Speer's Ruger data is not much hotter than Hodgdon's Trapdoor data.  Good luck deciding what is meant by "Trapdoor" level loads - is it 18,000 cup or 28,000 cup?

Many 300-grain bullets will over-expand at short range when launched in 50,000 cup loads.  Choose the bullet for the game, then decide what velocity it can take.


.

[Larry Gibson]

Its these very kinds of issues with reloading manuals that causes me to tell fellow reloaders to use them as guides, not the Gospel.  There are numerous discrepencies between reloading manuals other than this issue.  The problem with listed pressures is; How were the pressures measured?  Most of the ammuntion manufacturers and publishers of reloading data now use Electronic peizo transducer type methods of pressure measurement. A couple do still use the C.U.P. method as that is the SAAMI method.  There is a distinct difference between peak preassure as measured by the CUP method and the peizo transducer or strain gauge methods. There are other variables also such as where the transducer is placed. All NATO ammuntion pressures are measured with the placement at the case mouth.  Many attempt a conversion of CUP to psi (modern measurement). There is a formula for it but the problem is the constant in the formula scews the numbers of the bottom and top thirds of the pressure spectrum. The middle third is pretty close.  With modern pressure measuring equipment the TD level MAP (Maximum Average Pressure) is 28,000 psi, with Marlin leverguns it is 42,000 psi and the upper MAP for "modern guns" (assuming Ruger #s 1 & 3s and Siamese Mauser conversions) there is no MAP that I am aware of. If we take the 50,000 CUP listed by Hornady and Hodgdon and do the conversion we have basically 58,000 psi.  However, every one here knows the Rugers are made with cartridges with MAPs of 62-65,000 psi. 

So if you are loading for one of these "modern rifles" you have to let your own judgement be your guide.  In my case I have a Siamese mauser I built years ago with a 24" Shaw barrel on it.  I have one load that pushes a Barnes 400 gr SP right at 2300 fps.  The psi per my Oehler PBL is 62,700 psi(M43). I don't shoot many of those with the ft lbs of recoil being 49.2.  My most often shot jacketed bullet is the 400 gr Speer over 4895 which generates 36,200 psi(M43) at 1978 fps.  My heavy cast load is a soft cast Lee 500 gr GC over 4895 at 50,900 psi(M43) and 1770 fps.  My general shooting load is the same as used in my H&R Officer's Model; a hard cast 400 gr bullet (commercial or 457124) over 36 gr 4895 with a dacron filler for 22,400 psi(M43) and 1391 fps. 

I have shot the 300 gr Sierra over 55 gr of H4198 (max listed load in my older Lyman manual) for 2296 fps but that was some years back and I've not pressure tested it yet.  I believe that was a bit of a compressed load.  Perhaps with newer H4198 you can get 58.5 gr in the case without too much compression?  Not sure I want to try as the 400 gr Barnes load is worse than a George Forman right cross when shooting from the bench and I even use a sissy pad!

Larry Gibson

[NFG]

G

[Lone Star]

The advice of "start low and work up slow" is okay, as far as it goes.  But this thread is about the .45-70,  and loading it to the "three levels of pressure" is wrought with potential disaster.  If loading for the Trapdoor, do you start low and wait until the action gets sticky?  Or until the primer pocket gets loose?  Of course not - but what pray tell would the reloader use to determine if his load was safe for this weak action without testing it to failure?   He'd use pressure-tested data, period. 

Okay, say you own a Siamese Mauser M98 and it is rebarreled to .45-70.  I've owned one for thirty years, but these rifles are now over 100 years old.  Some will say that "M98s are designed for 65,000psi pressures" - but these M98s were not!  There can be a big difference between the strengths of a 1903-vintage M98 made in Japan and one made in Germany in 1940 - metallurgy and heat treatments changed, as well as the use and abuse the action may have seen.  How do you tell what a safe maximum load is with these rifles?  Start low and go until the primers get loose?  No, you use pressure tested data - but which one?  35,000 psi or 40,000 psi or 50,000 psi?  Or just say the heck with it and go for 65,000 psi?

I love to read foolish statements like "I've used this hot load for years and my rifle hasn't blown up".   Is the measure of safety that the rifle hasn't blown up yet?  Fools.....

The owner of this site has made it abundantly clear that IHO the use of non-published loads is a bad ideal.  On this forum I will strongly support that notion.  Those who want to argue may want to do so on another forum to avoid problems.  Safety is of paramount important on this family-oriented site.


.

[NFG]

G

[Autorim]

I think I will stay with my old Sierra manual with their maximum charges as listed. Some of the velocities listed in this post are in the .458 mag range. Why try to make an old cartridge do something it is not designed to do.

I have been loading since about 1962 and seldom try to approach maximum loads in any cartridge. It seems that so many reloaders want to wring out maximum velocity when they might be better off with a larger caliber cartridge of greater powder capacity loaded to a more reasonable level. If I need or want more than the 45-70 will give me at moderate pressure, I will buy or build a .458 mag. My current and only 45-70 is a Ruger No. 1 and 2100 fps with a 300 grain bullet is all I really want to handle. I think it will do anything I will ask it to do.

The 45-70 is a great cartridge and one of my favorites due to ease and flexibility of loading plus a lot of history behind it. I love to hear those big bullets hit.

When I get tired of getting kicked around, I reach for the .222 or .257 Roberts - other oldies and favorites of mine.

[NFG]

G

[handirifle]

This copied from the Hodgdons ONLINE reloading data for the "modern rifles" of 45-70 caliber.

300 GR. SIE HP  IMR  IMR 4198  .458"  2.525"  54.0  2253  31,800 CUP  58.5C  2450  43,000 CUP       
300 GR. SIE HP  Hodgdon  H4198  .458"  2.525"  59.5  2394  37,300 CUP  63.0  2532  50,000 CUP       
350 GR. HDY JRN  Hodgdon  H335  .458"  2.540"  57.0  2016  32,200 CUP  63.0  2174  47,300 CUP       
350 GR. HDY JRN  Hodgdon  H322  .458"  2.540"  52.0  1898  25,800 CUP  57.0C  2143  41,100 CUP       
350 GR. HDY JRN  IMR  IMR 4198  .458"  2.540"  49.0  2118  37,700 CUP  52.0  2212  43,900 CUP       
350 GR. HDY JRN  Hodgdon  H4198  .458"  2.540"  50.5  2104  35,100 CUP  56.0  2300  50,000 CUP       
400 GR. SPR JFP  Hodgdon  H335  .458"  2.540"  54.0  1883  31,900 CUP  60.0  2057  49,800 CUP       
400 GR. SPR JFP  IMR  IMR 4198  .458"  2.540"  47.0  1954  35,400 CUP  50.0  2089  47,100 CUP       
400 GR. SPR JFP  Hodgdon  H4198  .458"  2.540"  48.0  1915  31,800 CUP  53.0  2108  49,100 CUP       

 

Do with it what you will. To my thinking, many of these bullets will most likely fragment, at those velocities, upon hitting anything substantial.  The 45-70 will kill anything on the planet, with the right bullet design and weight and at the correct velocity.  Not always at the fastest possible velocity either.

When users of Garrett's ammo kill huge african animaks with a 530gr cast bullet at 1600fps, the point of pushing them higher is moot.  most you'll get out of a 2400+ velocity with a 300gr HP is a flatter trajectory, but it will never be a 308 Win in that regard.

[Larry Gibson]

Just a couple comments here; first of all anyone who reloads should use at least one manual and should not go beyond that until they have considerable reloading experience.  More manuals to cross reference with is even better.  Still, I always suggest that no one take a manual as "gospel". Thus the adage to "start low and work up" always applies. Even if it is just to the manual maximum. One should never just load the maximum load in any manual and assume it's safe in your rifle.

There are numerous cartridges that are loaded to different levels depending on the actions made for them. Granted one should not try to make a .458 out of a 45-70 in a TD action but if you have a 45-70 on the same action that is made or handles a .458 then loading up the 45-70 to close to the level of the .458 is prudent. That is if your shoulder can handle it.

I also do not subscribe to the oft stated "these actions are 100 years old". indicating that they have somehow gotten weaker with old age.  I also do not subscribe to the thought that Mauser actions were "designed" for only the pressure of whatever cartridge they were to be made in. The Mauser brothers did not deal in psi or CUPs when they built their actions in the 1800s. They dealt in "atmospheres".  The nearest I can find through a lot of research is the M91 Mauser was designed by them to withstand proof loads of 4,000 atmospheres. That is around 74,000 psi by todays modern peizo measuring systems.  I do not think the Mauser brothers would have lowered that for later actions.  The Japenese built, with German assistance, the Siamese actions used today for conversion to 45-70. I've had mine since I built it in '75.  The Japenese were making some very fine and well made rifles and actions back then.  The Arisaka is well known for being one tough action.  The Mauser action is most often mentioned as one of the "modern" actions that the 3rd level of 45-70 loading can be used in, along side the Ruger #s 1&3. There are a lot of m98s out there that have been abused over the years and are suspect. There are also some that were poorly made (the chinese M98 for example) that are suspect. There are also a lot of other actions, M70, M94, M30, M721/722s etc. ad nauseum that also have been abused and are suspect.  The age of an action has little to do with it. It is the quality of manufacture and the condition. The Siamese mausers were of excellent quality so one should judge them by condition.

As to the loads I use in my Siamese mauser; Most are either TD level loads or those for Marlin lever guns.  A  few venture into the 3rd level and the Barnes 400 gr load is pretty much max, for me anyways.  I measure pressures and do not have to take the manuals word for it.  The loads used for my TDs are safe TD loads. The loads I lod for Marlins are safe for Marlins and the loads for my Siamese Mause are safe in my Siamese Mauser.  Every reloader should load only for what is safe in their rifle. As was mentioned. it is the rifle (firearm) that determines the pressure level, not the cartridge.

I'll aslo remind everyone that comparing old "psi" figures with C.U.P. is many times an apples to oranges comparison.  Further more comparing C.U.P. to modern peizo/strain guage pressure measurements can also be an apples to oranges comparison.  If pressures are listed as "psi" then read further to hopefully find out if it is a conversion of peak pressure or of peizo type measurement.  Also try to determine if it is a maximum allowable pressure or a maximum average pressure. There is a considerable difference between them.  I'll also caution anyone to not compare modern CUP against modern psi unless you have considerable knowledge of how to do it. Even if you know how then it is only an educated guess.

Larry Gibson

[Lone Star]

Besides I've never heard or seen written, by anyone proporting to be an expert on the M98, mention that high pressure number you listed, Lonestar.

I do not believe that an "expert" would ever do that.  However, one poster in this very thread did load in this range, that's why I made the comment about 65,000 psi.  That poster was you.

In my case I have a Siamese mauser I built years ago with a 24" Shaw barrel on it.  I have one load that pushes a Barnes 400 gr SP right at 2300 fps.  The psi per my Oehler PBL is 62,700 psi(M43). I don't shoot many of those with the ft lbs of recoil being 49.2.

I'll also caution anyone to not compare modern CUP against modern psi....

With the .45-70 cartridge psi = CUP.  I have posted the Alliant chart before. Here it is again:






.

[NFG]

G

[Graybeard]

This thread seems to have generated some really hard feelings on the part of some members. Having read it I guess I don't really undestand just why. Perhaps something is in the trash can that was here that I need to read to better understand.

It seems the disagreement here is a rather minor flap as such things go and no one should be having the kinda hard feelings that clearly seem to have popped up from it based on private messages to me.

Let's all calm down, take a deep breath and count to ten. Now get back to talking stuff without any ill feelings toward each other. OK?

[fourty-five-seventy]

I use the sierra 300gr hp with 52.5gr of H4198 in winchester brass and it is about as close to the factory winchester loads as far as I can tell except better cause I rolled them my self