Could anyone with reloading software on their computer give me a little help? I am trying to work up 45-70 loads for my Marlin 1895 CB with IMR 4064 and Hornady jacketed 350-grain flatpoints. (I also intend to try the same thing with 405-grain Remingtons.) In the 350-grain Hornadys, I will be working upward from a start load of 53 grains of 4064 to 60 grains. (I am using Winchester brass, because it has a little more case capacity than the others, and I need that capacity to get 60 grains into the case under that bullet without compressing it severely; and CCI 200 primers.) I think 60 grains should be plenty safe in my rifle. I am told that Hornady's manual, 3rd edition, gives 59.9 grains with a 350-grain roundnose bullet, at 1900 fps. (However, the 5th edition of the Hornady manual wimps out and gives only 57.6 grains as max, at 1800 fps.) Nick Harvey's Practical Reloading manual gives 60 grains as max with a 350-grain bullet at 1950 fps. It's a slow powder, by 45-70 standards, and I believe that at 60 grains it is nowhere near the 35,000-40,000 CUP peak pressures that I think should be the maximum in the 1895.

The question I would like help with is this. I think I have room in the case, with some more compression, to go up to 62 grains of 4064. What peak pressure can I expect from that load, using Winchester cases and the Hornady flatpoint bullet?

[ 08-08-2003, 21:55: Message edited by: BigBrass ]

I don't know the answer to your questions but I am sure that some on on Marlin talk would. It is located on the Marlin web page and it's users seem to be quite knowledgeable on 45-70 matters.

Mikelravy: Thanks; I had posted the same question on Marlinfirearms.com, but I have not had any responses yet. I was hoping someone on this forum with Load From A Disk or Quickload or one of the other similar software programs could plug in a couple of numbers, hit a button and give me figures for peak pressures and velocities for 60-62 grains IMR 4064 with 350-grain bullets and large rifle primers in Winchester brass.

Bigbrass,
I checked quickload... your results are far too high a pressure for me to share. DO NOT USE YOUR BIG LOADS.

find another powder, or something, like blc-2, 748, or rl7, and work up.

speer has some pretty good rl7 loads in their books for 45/70

jeffe

RL 7 is an excellent powder for heavy .45/70 loads, with IMR 3031 not too far behind. Case capacity is a serious limiting factor in large-caliber straight-sided cases like .45/70 and .38/55, meaning powders in the burning range of IMR4198, RL 7, and IMR 3031 seem to be generally more satisfactory.

[ 08-09-2003, 16:56: Message edited by: eldeguello ]

Hodgdon manual shows you can get around 2000fps@30,000cup in 24" barrel 1895 and the IMR4064 is midway between the burning rates. Quickload struggles with straight wall calibers, so I poked around to see if the 4064 burn rate data is off. For the H powders, Quickload is about 14 to 18% higher pressure for the same velocity. For the 458 Wmag, the 4064 data was about 12% high, so from this, I assume 4064 burn rate is close and it is the straight wall calculation that is in error.

Given this, after calibrating quickload, the estimate for 28" barrel and the 350g Hyd, was
1828fps@26,000 cups for 55g. Kinda makes sense compared to IMR data of 405g Win, 25" and 55g for 1780fps@26700 cup.

Anyhow, this is all computer imagination, but I would be curious as to your measured velocity for the 55g IMR4064 and the 350g bullet.

rgds,

steve

Thanks for your comments, guys - they were helpful.

Over the weekend, I worked up loads in my 1895 CB (26" barrel) with IMR 4064 from 53 grains to 60 grains, using the Hornady 350-grain flat-point bullets, off of sandbags at the bench. 58 grains was the best -- 2.4 inches for five shots at 100 yards. This is pretty good accuracy, considering that (1) I shoot that rifle without a scope, and (2) my eyes are not very good. A better shooter with better eyesight could have shot much smaller groups, I have no doubt. I do not have a chronograph; but I think that load is probably giving me about 2030-2050 fps out of my 26" barrel. 60 grains produced a 3.4" five-shot group. There were no signs of undue pressure from the brass at 60 grains (no sticky extraction, and case stretch was only about .002"); but I don't think I can recommend that 60-grain load to others, because the recoil was enough to kick open the action. (I had trouble keeping the lever fully closed when the gun discharged.) This may mean that 60 grains is too hot, despite the absence of other pressure signs. I will continue to test whether the slow powders are more accurate in my long Cowboy barrel than the faster ones like Reloder 7 and IMR 3031. I plan to try try 53-60 grains of Varget next.

BigBrass

[ 08-12-2003, 01:10: Message edited by: BigBrass ]