43 Spanish Rolling Block revisited

[brstevns]

I have been playing with a 43 Spanish RB for the last couple of years. Have used BP, 5477 and Unique powders. Has anyone else tried any other powders. I mean actually tried, not just read about or someone has recommended to them ?

[RFP]

I got one of the Argentine rolling blocks about 6 wks ago. Have used bp and trailboss powders.

[curator]

Sure, I have used both SR4759 and IMR4198 with excellent results. Standard load 1/3 of black powder load (in grain weight) plus dacron filler and Lyman .439 boolit.

[bubba.50]

I had a Spanish Reformado & used both 4759 & 5744 in it with good results with 'trapdoor' level loads. accuracy was good & recoil was mild.

also used the same level loads in my Danish 12.7mm that was re-chambered to 50-70.

[brstevns]

Interesting , trail boss and 4198 , I have both of those.

[RFP]

I use 17.5 gr trail boss and Lyman .439. Have shot several 3 shot groups around 1 1/2 inches at 100 yards. Windage is perfect but shoots a bit high..... like 12 inches high. If I remember right, 5 shots averaged 1135 fps

[brstevns]

I use 17.5 gr trail boss and Lyman .439. Have shot several 3 shot groups around 1 1/2 inches at 100 yards. Windage is perfect but shoots a bit high..... like 12 inches high. If I remember right, 5 shots averaged 1135 fps

No problems with pressure ?

[Drm50]

I had a 43 Span RB for several years. I started out with unique and had some problems and went
to fillers and paper disc over powder. With light loads was not getting enough pressure to seal
case. I went to IMR-4198 and found it to work a lot better. I think I tried IMR-3031 also. I had a Rapine 385g RN mold, the only bullet I used in it.

[KenH]

Per QL using a 45-90 (similar to .43 Spanish Reformato) case, 405 grain bullet, and 32" barrel I get the following with Unique and Trail Boss powders.

Unique (12 grain. 1145 fps) 14,160 psi;
TrailBoss (15 grain, 1133 fps) 20,478 psi

That's with same bullet, same everything except powder. That's why I prefer Unique over Trailboss, even though TrailBoss does fill the case much better.

I think perhaps the OP has the standard .43 Spanish rather than the Reformato, but the straighter case of the Reformato is more similar to the 45-90 than is the bottle neck .43 Spanish.

Ken H>

[brstevns]

Yes, Mine is the standard 43 Spanish. I also use 12 gr Unique as my standard load. Just want to try some other powders. Never heard about using 3031 ?

[Gewehr-Guy]

Reloader 7 should work well in the 43 Spanish, it's my favorite in the 43 Mauser, a very similar cartridge.

[KenH]

Yep 3031 works good - I've not loaded in .43 Spanish, but use in 45-70 for my heavier loads (1400 fps+) and it works really good for that. Per QL the pressures are lower than some of the other powders. I would like a ball or flake type powder because the rod type 3031 is harder to feed thru powder measure.

Ken H>

[brstevns]

I guess I am worried about the strength of the Argentine Rolling Blocks. I would like to give Trail Boss and Imr 4198 a try with the Lyman bullet.

[KenH]

Anytime a rifle that's well over 100 yrs old is used, I am VERY cautious about action strength. While they are generally rated for "Trapdoor" loads, there's been some discussion if this is 18,000 psi or 26,000 psi. Seems like the actions were originally rated for 18,000 CUP, but realize CUP (Copper Unit Pressure) does NOT relate directly to PSI rating.

Myself - I tend to hold a lower pressure rating for my old guns, usually NEVER load more than 14,000 psi, and most of time in the 10K psi range. As mentioned before, I'm not a TrailBoss fan because it's such a fast powder the pressure spikes pretty high and falls rapidly. For paper punching I like loads in the 1,000 fps range, or maybe less?

Allow me to fall back to 45-70 loads since that's what I load for, other than 50-70 in a couple of Swedish Rolling Blocks I have. With 405 grain bullet, 37" barrel I get the following from QL. Understand, QL has a reputation for not getting pressures correct on straight wall cases - and I find sometimes that seems to be true because of the difference in calculated fps vs chrono'd fps with some powders. Other powders give chrono'd fps VERY close to calculated fps.

22 grain of IMR4227; 1196 fps, 9669 psi chamber pressure
17 grain TrailBoss: 1196 fps, 27,520 psi (I would not load this in an old RB)
31 grain 3131: 1190 fps, 8525 psi (see why I like 3031?)

Then for paper punching at home I use 9 grains Unique for 1,001 fps at 10,629 psi

The above are ALL QL calculated fps/psi for my Pedersoli Sharps with 32" barrel. The actual chrono'd for 3031 is only slightly lower chrono'd fps. With the same 9 grains Unique, the chrono'd is 896 fps with a ES of 6 fps for 4 shots. Must tilt barrel up before each shot to get that close ES.

Ken H>

[brstevns]

Alright,think I will forget about using Trail Boss i know I have no 3031 but do have some IMR4227. Any thoughts as to what a good starting or mild load would be using the Lyman .439 bullet

[KenH]

I'm a little uncomfortable posting these loads to an open forum, these are just calculated loads and do NOT indicate what is good for any other rifle other than a "theoretical" rifle from QL.

Understand, your .43 Spanish is a bottleneck cartridge and will NOT!!! be the same as below. These are just guidance to see how different powder charges affect pressure and velocity. Please be aware of this, and DO NOT!!!! take the following as "loads" for your rifle. I would think 15 to 17 grains of 4227 would be a good starting load and work up from there. Of course, if you have to drive a ways to shoot, it's a hassle to load a couple of rounds to try. I just walk out back door.

Per QL, and using a 45-90 case since that's "close" to a .43 Spanish Reformato, (assuming 37" barrel), 400 grain bullet, with 4227 powder

20 grains; 1076 fps; 6131 psi
25 grains; 1294 fps; 9230 psi
30 grains; 1500 fps; 13,348 psi (that would be pushing in my mind)

Now, same loads in 45-70
17 grains; 990 fps; 5923 psi (just a good plinking load and maybe a good starting place?
20 grains; 1135 fps; 7955 psi
25 grains; 1371 fps; 12,462 psi
30 grains; 1592 fps; 18,717 psi (that would be pushing in my mind)


So, from the above you can see the difference in case size makes a good bit of difference.

Ken H>

[1616s16]

I use 2400 at a 45 70 load

[KenH]

How many grains of 2400 and what weight bullet?

[brstevns]

I'm a little uncomfortable posting these loads to an open forum, these are just calculated loads and do NOT indicate what is good for any other rifle other than a "theoretical" rifle from QL.

Understand, your .43 Spanish is a bottleneck cartridge and will NOT!!! be the same as below. These are just guidance to see how different powder charges affect pressure and velocity. Please be aware of this, and DO NOT!!!! take the following as "loads" for your rifle. I would think 15 to 17 grains of 4227 would be a good starting load and work up from there. Of course, if you have to drive a ways to shoot, it's a hassle to load a couple of rounds to try. I just walk out back door.

Per QL, and using a 45-90 case since that's "close" to a .43 Spanish Reformato, (assuming 37" barrel), 400 grain bullet, with 4227 powder

20 grains; 1076 fps; 6131 psi
25 grains; 1294 fps; 9230 psi
30 grains; 1500 fps; 13,348 psi (that would be pushing in my mind)

Now, same loads in 45-70
17 grains; 990 fps; 5923 psi (just a good plinking load and maybe a good starting place?
20 grains; 1135 fps; 7955 psi
25 grains; 1371 fps; 12,462 psi
30 grains; 1592 fps; 18,717 psi (that would be pushing in my mind)


So, from the above you can see the difference in case size makes a good bit of difference.

Ken H>

Thanks , I was thinking around 18 gr for the IMr 4227 and around 24 gr for IMR4198

[RFP]

As far as I can tell ... and that's just by checking and measuring brass... I've have had no pressure problems . Some of my brass has been reloaded 3 times.