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Posted By: ORmtnman Maximum 45-70 load? - 03/05/09
I would like to hear some opinions on what you all believe is a good maximum load for the 45-70 using Laser Cast 405gr FP bullets and IMR-3031 powder in a Marlin 1895G. I am looking for a load that will be used strictly (and rarely) for that one in a thousand chance that we may be charged by a large brown bear while fishing remote coastal areas in Alaska. So I am not as concerned about brutal recoil as I am about having the best chance of stopping a bear if needed. However, I also think it would be kind of nice if I didn�t kill myself with my own load before the I even get the chance to go fishing.

Laser Cast sent me their load data for the 1895 and it shows 38.5grs max of 3031. I worked up to 38.5grains and it just felt like a very light load (recoil wise). I was talking to another fella at the range and he stated he uses 40grs of 3031 with the same bullets and gun. So I worked up to that and it still seems light to me. I did a google search and discovered that many people load wayyy more then this � as high as 50 grains of IMR-3031 with the same bullets that I am using. That seems like a very huge increase from the published data to me. I am not very comfortable moving further because 40grains is already past the load data specs. However, since I don't have much experience loading the 45-70, maybe my fears are unfounded?

So, I would really appreciate some input on why there seems to be such a huge difference in what folks actually use and the published load data. I know that some folks don�t like to discuss their loads on a public forum so a PM would be great also.

TIA
Posted By: Vic_in_Va Re: Maximum 45-70 load? - 03/05/09
There are typically three levels for loading the 45/70. The first being the "Trapdoor" loads, which hold the pressure at the original level when the round was introduced. Second is the "Lever-action" which may go to 40K CUP, and third is the level for Siamese bolt rifles and others with the same action strength. These can go 50K CUP.

Laser cast is probably keeping the pressure very low in deference to the Trapdoor class rifles. Also, is the bullet hard-cast and gas-checked? Leading could be an issue.

Hodgdon shows 55 grains 3031 with a 400 grain jacketed bullet with 37.3K CUP and 1971 fps as a maximum load. The Marlin is good to 40K. Substituting a cast bullet for a jacketed one would likely lower the pressure.

Their trapdoor section shows a starting load of 45.5 grains of 3031 for 17.3K CUP and almost 1600 fps, so your load would be pretty sedate.



Posted By: DoubleRadius Re: Maximum 45-70 load? - 03/06/09
You really should not substitute jacketed load data for cast bullets, although lots of folks do so. The extra velocity and pressures of jacketed loads can cause poor accuracy and leading, not to mention poor bullet performance on game. Especially considering that you want the rifle for bear protection, I'd use a tough jacketed bullet intended for the .458 Magnum. I shot a brownie with the 350 Hornady in my M98, it worked great. Most 400-grain jacketed bullets are quite soft.

There is a lot of dispute as to what pressure a certain .45-70 rifle should take. Some say the Marlin is "good to 40K", others disagree. Below is what the most popular loading manuals show:


Data Source�.Trapdoor�Marlin�.Ruger (CUP)
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
Factory��..�18,000 reported


.


Posted By: MontanaMan Re: Maximum 45-70 load? - 03/06/09
Originally Posted by DoubleRadius
You really should not substitute jacketed load data for cast bullets, although lots of folks do so. The extra velocity and pressures of jacketed loads can cause poor accuracy and leading, not to mention poor bullet performance on game. Especially considering that you want the rifle for bear protection, I'd use a tough jacketed bullet intended for the .458 Magnum. I shot a brownie with the 350 Hornady in my M98, it worked great. Most 400-grain jacketed bullets are quite soft.

There is a lot of dispute as to what pressure a certain .45-70 rifle should take. Some say the Marlin is "good to 40K", others disagree. Below is what the most popular loading manuals show:


Data Source�.Trapdoor�Marlin�.Ruger (CUP)
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
Factory��..�18,000 reported


.




+1 .......I'd never load cast bullets to jacketed levels.

I've used 53 grains of IMR-3031 with a 400 grain bullet in an early Marlin 1895 for 30 years.

MM
Posted By: BigBoreFan Re: Maximum 45-70 load? - 03/06/09
I'm not knocking LaserCast, but in my experience you want a cast bullet with a gas check since you are going to push the bullet to max. Take a look at beartooth bullets ecspecially the Pile Driver and the Pile Driver Jr. You can go online and get the load data. These bullets were designed to function in the 1895 Marlins. I also have had good luck with Cast Performance bullets. I have several types of Laser Cast bullets and they shoot great in my light loads for my 1885 Browning and slower velocity loads in my Contender. Check out the load data from Hodgdon as they have loads for IMR and their own powders.
Posted By: ORmtnman Re: Maximum 45-70 load? - 03/06/09
"I've used 53 grains of IMR-3031 with a 400 grain bullet in an early Marlin 1895 for 30 years."
53 grains with cast lead bullets?
Posted By: Vic_in_Va Re: Maximum 45-70 load? - 03/06/09
It may sound like I was recommending using a cast in place of a jacketed, but that was not my intention, sorry about that. I should have also used the starting load as an example.

I am using a Cast Performance 420 at 1650 fps and get tremendous penetration with this bullet. It is a hard-cast, gaschecked bullet and is accurate in my rifle without any leading problems. But, I am using H4198 instead of IMR 3031.

The Beartooth bullets recommended by BigBoreFan are also a good choice.
Posted By: 284LUVR Re: Maximum 45-70 load? - 03/06/09
Vic, what's the recoil like with the CP 420s ?I am currently shooting 300 Noslers out of my 1895SSS over 63 grains of Benchmark and the recoil is pretty darn sharp. As a couple of the gun writers here have said, "really gets your attention"

I'm told that shooting the heavy 405 and 420 bullets over 4198 or 3031 that the recoil is more of a push than the very sharp jolt.

I will be putting a Kick-Eeze pad on my rifle soon and that will undoubtably make it a different animal.

TIA,284
Posted By: Vic_in_Va Re: Maximum 45-70 load? - 03/06/09
It's somewhat heavy but not sharp. I also have a 300 grain load, using 55 grains H4198, and it is pretty sharp. When firing the two loads during the same range session, I could tell a difference.

I am getting 2226 fps with the 300 grain load, and the trajectory is very similiar to my .30-30. Recoil isn't...
Posted By: the_shootist Re: Maximum 45-70 load? - 03/06/09
Why does it have to be a lead bullet load? Do jacketed bullets not work on bears? What I have seen with the 45-70 is that even slow traveling bullets penetrate like a freight train, and if it is for bear defense, range should not be an issue. Go with a 405 gr Remmy flatpoint and take it as high as is safely manageable. Benchmark powder works good for me.
Posted By: Klikitarik Re: Maximum 45-70 load? - 03/06/09
I differ with the idea that one should not use data for jacketed with cast bullets. A properly hard cast bullet can actually be driven quite fast, and may even need to be fired at higher pressures simply to fit the barrel well. (Normally one would buy or pour the hardest cast bullets a bit over bore diameter to accomplish the job properly.)

But one need not simply load to maximums with lead using jacketed load data. By working up with the jacketed data as the highest potential stopping point, you'll find the spot where accuracy is best and leading starts. (Of course, in a bear load, leading or not is a non-issue since you aren't going to be shooting bunches of them at bears all at once.)

I have found that the 1700s seem to be a relatively easy speed level to shoot ordinary cast bullets to. Often, depending on various factors: gas check or plain, bullet diameter, bullet lube characteristics, alloy material, etc, one might be able to get more or less speed than that. The nice thing about using a cast bullet with a properly configured nose in that weight is that it will completely penetrate most bears from any angle with plenty of authority along the way. So, the advantage of using cast it that one doesn't need to really push them as hard to accomplish what one might with jacketed bullets.

FWIW, I have had no trouble getting 18-1900 fps with both jacketed and cast 405-420 grain bullets in my Guide Gun (18.5" barrel) using published jacketed load data for H322. But, IME, even a decent 320 grain bullet from a 45 Colt carbine moving at the more stately speeds of 1500 fps or so can penetrate as well as the bigger faster bullets do. Hard cast bullets have their own rules.
Posted By: Vic_in_Va Re: Maximum 45-70 load? - 03/07/09
That is why 1650 fps is really all the farther I have thought about taking the CP LBT style bullet. Certainly, there is no need to go much faster than the mid-1700's. With the 300 grain load, I was tring to duplicate the trajectory of my .30-30 with a 170, and it is actually a little faster, but accuracy is nice enough that I think I'll stay right where I'm at with that one.

BTW, my rifle is a Guide gun, also. I gave the 22 incher some consideration, but I really liked the way the GG handles in thick cover, and when I take to the trees for deer.
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