As everyone knows there are 3 different clases of loads for the 45-70. Does the H & R fall under the "trapdoor", the "marlin" or the (I seriously doubt this one) "Ruger" class. I wanted to try some loads in the 35,000 psi range but want to be sure.

Which H&R .45/70 are you talking about? The handi-rifle kind, or their replica Trapdoor Springfield? If the latter, it is limited to the same loads as the original, despite being made of better steels. However, the break-open design can handle loads as hot as a Marlin.

I got a handi rilfe 45/70 and wondered the same question.

I went through stress analysis with the help of others that showed the handi rifle was so much stronger than the brass, that it would take any load any other 45/70 would.

I posted it.

Someone said it was all b.s. becuase I lack credentials.

So I overloaded the rifle to 88 kpsi when the brass flowed into the extractor.

I posted those results and a picture of the primers.

Someone said it was still b.s. and didn't prove anything.

The lesson here is about the phycology of handloading, not facts.





]link to picture of brass



Here is my test data:

45/70 work up with; 405 gr cast with lube bands, CCI 200 primers, Win

brass, old Unique [dirty] powder, chamber well lubricated between

firings with CLP for max bolt thrust.



Quickload calculation of pressure and velocity with 405 gr, Unique



shot 0) 15 gr, 24,700 psi, 1271 fps, no shot fired, listed for Quickload reference point only

shot 1) 18 gr, 33,217psi, 1403 fps, primer looks fine.

shot 2) 20 gr, 39,435 psi, 1485 fps, primer is fine

shot 3) 22 gr, 46,133 psi, 1563 fps, primer looks flat.

shot 4) 24 gr, 53,334 psi, 1637 fps, primer is flat.

shot 5) 26 gr, 61,067 psi, 1709 fps, primer is top hat and flowing,

action popped open and case ejected on firing

shot 6) 28 gr, 69,366 psi, 1778 fps, primer is top hat and flowing, case

head expansion .001", action popped open and case ejected on firing

shot 7) 30 gr, 78275 psi, 1846 fsp, case head expansion .0015" action

popped open and case ejected on firing, some leading in the muzzle.

shot 8) 32 gr, 87,841 psi, 1911 fps, case head expansion .0025", case head separating where case head is flowing into the extractor, action popped open, some leading in the muzzle, and case ejected on firing, primer is spreading out .010"



There was no change in headspace, but I had to stop the work up because of case head separation where the case head flowed into the extractor.



Reference loads:



1) "Loads for the 45/70" from the H.P.White laboratory via "American

Rifleman" 1950~1968 via "NRA Handloader's Guide" 1969 says:

405 gr Rem S.P., 17.5 gr Unique, 1286 fps, 25,240 pounds pressure, for 1886 Win



2) "Lyman's 47th" 1992 says:

400 gr cast, 16.5 gr Unique, 1286 fps, 27,000 cup, for 1886 Win



3) "Lyman's 47th" 1992 says:

385 cast gr cast, 17.5 gr Unique, 1411 fps, 38,500 cup, for Ruger #1



http://glocktalk.com/attachment.php?s=74be3774b80a312630c42bf31adc9af3&postid=990876

You are so right, Clark! Some are totally wedded to the idea that to exceed book maximum is tantamount to suicide. Any given reloading manual could publish a maximum load showing a negative muzzle velocity, and some experts would insist the load could not be increased.

Aren't those Handi-Rifles produced in hot calibers, like the .270 Winchester? This alone should give a hint as to what load levels it will stand.

I used to load 30-30 for a hadi rifle to levels beyond listed maximums. After a large number of such loads the firing pin "mushroomed" or bulged to the point it was dragging against the firing pin openning in the face of the block. This began causing hang fires and mis fires. These loads were hot enough that I had the traditional signs of high pressure i.e. flattened and cratered primmers. My rifle was an older model before the introduction of high intensity rounds and perhaps the temper of the new ones is different.