Help me develop load/see pressure 45-70

joevh

joevh

Hammer Time Executive member
I have a Marlin 1895 Guide Gun 45-70 in stainless. I think it's a 2006 model - true Marlin before Remington mucked it up. I've had it for a number of years and would really like to take it elk hunting this fall - I know just the tangle of deadfalls and misery where it would shine! I could use some help with running a pressure ladder. I'm comfortable doing this with a bolt action, relying mostly on bolt lift pressure and ejector marks. I feel somewhat clueless with this lever action.

My previous load was 49gr IMR 4198, 300gr TSX, 2100 fps and very accurate. I shot a pressure ladder today with IMR 4198 and 250 gr Shock Hammer.
55 gr - 2363 fps. close to 100% full
56 gr - 2451 fps. at least 100% full
57 gr - 2486 fps. compressed
This was done with my new Garmin Xero C1 Pro. (very sweet little tool!)

Attached are pictures of the primers, left to right 55-57 gr. You can see a little more flattening on the 57 than the 55 in the pictures, but not really with a naked eye. The primers don't look bad to me. This is previously unfired Starline brass. Web measurements are .499 unfired, .506, .507, .507. The cases were trimmed to 2.04" as has been recommended here in order to crimp in the top groove and still cycle in the action. C.O.L. is 2.54". I tried crimping with my LFC die but it didn't seem to do much so I used my RCBS seating die and roll crimped it as part of the bullet seating.

I'm looking for guidance in finding pressure signs with this lever action. It's probably noteworthy that I gained 88 fps from 55-56 gr, but only 35 fps from 56-57gr, but I'm not sure what it might mean, and with only one data point for each, not sure how significant it is. There is precious little reloading data in the Hammer Hunter reloading guide for the 45-70, and not a lot elsewhere for 250 gr bullets. Any guidance in seeing pressure with these lever guns will be appreciated.

I would like to try a pressure ladder with Reloader 7 as well if I can find some, before I start shooting for groups - these are expensive bullets and I don't want to waste them. I know that Joe16 would say AA1680 will show faster speeds than 4198. I've also seen Les mention that he wouldn't us a ball powder in a straight wall case, but clarification on that would be helpful. AA5744 is next to 1680 on the speed chart, is extruded, and say's it's good in a 45-70, so that may be a good option as well, although I've had good luck with Alliant powders and feel that R7 is probably the best other option.

Thanks for any advice.
 

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RL 7 is my favorite powder for the 250 grain bullets in the 45/70. Just to clarify, I don't like compressed ball powder loads in a straight wall case. Those primers look good. You know you are over pressure when the case tries to self-eject. I've made that mistake before. AA5744 is a good powder for the 45/70. I'm not sure if you can get the highest velocities with it however. That all said, it is hard to beat 4198. I have an even older Guide Gun. I've also done well with H322. To be honest, I have not done a lot of Hammer load development for either one of my 45/70's.

I'd build a ladder starting at 56 grains of 4198 and work your way up. Accuracy will be more important than speed. I wish I could find more RL 7.
 
It's hard to define what a top load is for an 1895 levergun. Most reloading manuals limit loads to 28,000PSI. Hodgdon list loads to about 38,000PSI. Barnes data is said to be at about 40,000PSI.

Reading fired primers from a 45-70 isn't quite like reading primers from other centerfire cartridges. Most other centerfire cartridges run up into 60,000+PSI. Any primer from a load producing 30,000PSI from a levergun should still be well rounded on the edges.

FWIW - I ran a Barnes max listed load of AA1680 under a 250gr mono bullet in my 1895. The recorded velocity from the 18.5" barrel was 2,330 fps. I'd suspect that it was a rather hot load and don't fire too many of them. They are very accurate and hits at 300yds were possible, even though I would not shoot game animals at that distance. Shooting a 250gr at 2,300+fps really flattens the trajectory compared to a classic 405gr at 1,700fps.

Good luck and keep us posted. Use caution when looking for max velocities because classic signs of excess pressure aren't usually seen at levergun pressures.
 
I have a CVA Scout with a 26” barrel. I’m going to load the 250 gr. Shock Hammers for it. I’ll follow the Barnes Data. Maybe I’ll reach 2,900 fps. I’ve also got a supressor in jail right now for it. IMG_8165.jpeg
 
Joevh

I just saw this, I apologize for my tardiness😖 but it seems that Les, Charlie and the boys have you covered.

Close to 2500 ft per second with an 18-in Barrel is pretty smoking. I must Echo Les, you've reached pressure when you drop the lever and it tries to kick down and eject the bullet. That's a good place to back down one grain and shoot for groups. If you're using a drop tube you should be able to get a few more grains not many but a few of imr4198.

5744 is sort of wonky when you start getting close to top pressure and velocity but it'll give you both.

I never played with 1680 until I got my 45-90. But now I load it in my 45-90 and my 358 Winchester. I like what Les said about compressing ball powders. I've got no issue of putting a bullet to the top of it but as you compress ball powders the sides of the straight wall cases push out.

Joe
 
CharlieNY said:
It's hard to define what a top load is for an 1895 levergun. Most reloading manuals limit loads to 28,000PSI. Hodgdon list loads to about 38,000PSI. Barnes data is said to be at about 40,000PSI.

Reading fired primers from a 45-70 isn't quite like reading primers from other centerfire cartridges. Most other centerfire cartridges run up into 60,000+PSI. Any primer from a load producing 30,000PSI from a levergun should still be well rounded on the edges.

FWIW - I ran a Barnes max listed load of AA1680 under a 250gr mono bullet in my 1895. The recorded velocity from the 18.5" barrel was 2,330 fps. I'd suspect that it was a rather hot load and don't fire too many of them. They are very accurate and hits at 300yds were possible, even though I would not shoot game animals at that distance. Shooting a 250gr at 2,300+fps really flattens the trajectory compared to a classic 405gr at 1,700fps.

Good luck and keep us posted. Use caution when looking for max velocities because classic signs of excess pressure aren't usually seen at levergun pressures.
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Charlie,
I've been looking at the Barnes data for their 250gr TSX and they achieved 2609 fps with AA1680 at 42,000 psi. The loading manuals are finicky for this round, with so many different strength gun actions and different standards. It is indeed confusing to know what should be max as well as knowing what the signs of max look like in a lever action. I later shot 58gr and achieved 2525fps or so (not at home now to reference it) and the primer still looks about like the others, but I'm getting the feeling I'm pushing max for that short 18 1/2"(?) barrel. I think I'll try groups at 57 or 57.5 gr. You are right, compared with 1700-1800 fps with a 400gr bullet, these speeds make this lever action a point blank shooter for as far as I'd care to shoot an elk with peep sights. Will post further results when I get a chance to shoot more.
 
joe16 said:
Joevh

I just saw this, I apologize for my tardiness😖 but it seems that Les, Charlie and the boys have you covered.

Close to 2500 ft per second with an 18-in Barrel is pretty smoking. I must Echo Les, you've reached pressure when you drop the lever and it tries to kick down and eject the bullet. That's a good place to back down one grain and shoot for groups. If you're using a drop tube you should be able to get a few more grains not many but a few of imr4198.

5744 is sort of wonky when you start getting close to top pressure and velocity but it'll give you both.

I never played with 1680 until I got my 45-90. But now I load it in my 45-90 and my 358 Winchester. I like what Les said about compressing ball powders. I've got no issue of putting a bullet to the top of it but as you compress ball powders the sides of the straight wall cases push out.

Joe
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Thanks Joe, yours and Les's clarification on not wanting to compress ball powders suddenly makes sense to me - not a lot of compressibility with something that resembles sand! I have an opportunity to buy some 1680, so may pick up a pound of it to see how it does. Would you recommend magnum primers for that? I seem to remember a rule of thumb about ball powders being harder to ignite, and I would be normally shooting this in cold weather.
 
Call me Captain Obvious, but with the short barrel of the Guide Gun, you are not going to get much more velocity than you already are getting. If your barrel is drilled like mine for the internal muzzle brake, you are even losing more barrel length. That Barnes Data was done with a 24 inch barrel. It was also done with a Ruger #1. You don't want to run your levergun at Ruger pressures. It might be OK for awhile, but it will eventually destroy your gun. If you want more speed, see if you can find a Cowboy model with the 24 inch barrel, or take the big leap and see if you can find an 1886 in 45/90. Check out this speed reading that I got in my 45/90 "Howitzer" CVA Scout with the 250 grain Hammer.



250 Hammer Chrono 2.jpg
 
les said:
Call me Captain Obvious, but with the short barrel of the Guide Gun, you are not going to get much more velocity than you already are getting. If your barrel is drilled like mine for the internal muzzle brake, you are even losing more barrel length. That Barnes Data was done with a 24 inch barrel. It was also done with a Ruger #1. You don't want to run your levergun at Ruger pressures. It might be OK for awhile, but it will eventually destroy your gun. If you want more speed, see if you can find a Cowboy model with the 24 inch barrel, or take the big leap and see if you can find an 1886 in 45/90. Check out this speed reading that I got in my 45/90 "Howitzer" CVA Scout with the 250 grain Hammer.



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Captain Obvious, the Barnes data clearly states it was done with a 1895 Marlin, not a Ruger #1.

Sorry Les, I couldn't resist that; I'm not trying to be rude!

I'm quite aware that I will not achieve 24" barrel velocities with my 18 1/2" barrel. Their test was also run with a 250gr Barnes TSX, which according most of our beliefs, should produce more pressure and run slower than a 250gr Hammer. I'm just trying to find out where the max is on my rifle with this bullet so I can then back off and load for accuracy. My barrel is not factory ported, and I like it being short and handy for its purpose. I have plenty of other rifles that are faster, I'm just trying to maximize each of my rifles, and trying to find out where that is.


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Update:
I wanted to try some R7 but could only find it in 5# kegs locally, so bought a pound of AA1680. Got it up to roughly the same velocity as with IMR4198, but unlike the 4198, the AA1680 was not compressed and still had more room. I also used Fed magnum primers for this ball powder. During pressure ladder workups, a 4 shot group of a 4 gr spread with 4198 covered about 6", while the same ladder with 1680 made a 3/4" group. Not exactly knowing where I was with pressure, I settled on a load of 57.5gr 1680 at an avg speed of 2485fps out of an 18.5" barrel and a 3/4" group at 50 yards with open sights. This is the max load listed in the Barnes manual for their 250 TSX and only 124fps slower than they achieved from a 24" barrel, so I think I'm right there with pressure and satisfied with the velocity. It's crazy how much higher this load shoots than the 400fps slower 300 TSX load, which also shoots way higher than the 400fps slower 400gr load. These guns with open sights are not forgiving for shooting multiple loads! I am now pulling bullets from previous loads. This load shoots like a laser compared with previous loads. I will post the load under the HH load section.
 
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