43 Spanish Rolling Block revisited

[KenH]

RFP: You said a .439 Lyman bullet - is that .439" diameter? What grain weight? Have you slugged your bore for groove diameter? With 1-1/2" groups at 100 yds I'd be VERY happy with those groups. Since the .43 Spanish is not one of the cartridges listed in QL I can't run numbers on that, but with a 45-70 round with 4-5 grain bullet that's pushing limits of a RB action. Trailboss is such a fast powder the pressure peaks very quickly and falls very quickly, much more so than some other powders. I personally like a powder that builds a lower peak pressure and holds pressure longer down the barrel to take advantage of the longer barrel, getting higher velocity with less peak pressure.

BUT - as I said, with 1-1/2" groups you're doing things right.

Ken H>

[1616s16]

How many grains of 2400 and what weight bullet?

Sorry I don't grains of powder boolit weight 380g pc

[RFP]

439 diameter 370 gr. Give or take. Didn't slug the bore. I got these from buffalo arms. Wanted to try some before I spent money on a mould

[brstevns]

439 diameter 370 gr. Give or take. Didn't slug the bore. I got these from buffalo arms. Wanted to try some before I spent money on a mould

I believe it is the Lyman spanish mold . It makes some nice 370's

[Tom Herman]

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.

I have the same concerns here... I have a Danish Remington I'm working up loads for (as well as an 1868 Springfield in .50/70, and an 11mm Mauser).
It's encouraging that people here use Trailboss, and are still alive to tell about it.
The problem that I see, is that you would want to use a powder that mimicks the ignition time and pressure curve of FF or so black powder, so that the receiver doesn't see sudden spikes or other pressure excursions... 4198 does this, I believe 3031 does also.
Trailboss on the other hand, has a pressure curve that spikes about three times higher than FF or 4198... That seems like asking for problems to me...
I'll stick with 4198 loads not to exceed factory, or with FF/1.5F loads here.
These rifles are all 100+ years old, and I don't want to push my luck.
I did see what was left of a blown up RRB several years ago at a gun show: From what I remember, the builder/shooter tried to turn it into some sort of a 30 caliber magnum rifle.
The receiver failed due to excess pressure, but the block didn't (which was why the shooter wound up presumably seriously injured instead of dead).
There has been a thread recently about a Swedish fatality due to firing an unknown high pressure modern cartridge in an old rifle that looked like it was pretty ratty to begin with.
In that case, the block did let go and kill the shooter. Here's the link: http://castboolits.gunloads.com/show...Block-strenght

[brstevns]

I am not going to try TrailBoss in my Argentine RB for the reason you have given. I would like to try 4198 and some 3031 once I find a few mild loads. I have use 12 gr of Unique?

I have the same concerns here... I have a Danish Remington I'm working up loads for (as well as an 1868 Springfield in .50/70, and an 11mm Mauser).
It's encouraging that people here use Trailboss, and are still alive to tell about it.
The problem that I see, is that you would want to use a powder that mimicks the ignition time and pressure curve of FF or so black powder, so that the receiver doesn't see sudden spikes or other pressure excursions... 4198 does this, I believe 3031 does also.
Trailboss on the other hand, has a pressure curve that spikes about three times higher than FF or 4198... That seems like asking for problems to me...
I'll stick with 4198 loads not to exceed factory, or with FF/1.5F loads here.
These rifles are all 100+ years old, and I don't want to push my luck.
I did see what was left of a blown up RRB several years ago at a gun show: From what I remember, the builder/shooter tried to turn it into some sort of a 30 caliber magnum rifle.
The receiver failed due to excess pressure, but the block didn't (which was why the shooter wound up presumably seriously injured instead of dead).
There has been a thread recently about a Swedish fatality due to firing an unknown high pressure modern cartridge in an old rifle that looked like it was pretty ratty to begin with.
In that case, the block did let go and kill the shooter. Here's the link: http://castboolits.gunloads.com/show...Block-strenght

[KenH]

I agree about TrailBoss - never understand the recommendations for TB, other than it's a fluffy powder that comes closer to filling the case. I just don't like that really sharp excessive pressure spike right after ignition - much sharper spike than black powder. For the same velocity, the pressure will be at least double of 4227, 4759, 3031, etc. For a fast powder, Unique works good, just has a tiny bit in case.

Tom - do you have any pressure curves for black powder? The only curves I've found were hand drawn. While these may well be fully accurate, I'd like to see actual printed pressure curves.

Ken H>

[Tom Herman]

Ken,

I've searched the Net for pressure curves, and found a few.
Getting ready for work right now, so I can't offer any up at the moment.
Should be able to post links tonight.
I stopped using Trail Boss when I was shooting revolvers at 100 yards, and the TB loads would fall something like 3-4 feet under the targets.
Those were max pressure loads, just not up to snuff.
Using nowhere near maximum Unique loads, I got the bullets to about hit the targets with a 6 o'clock hold...

[NYBushBro]

Phil Sharpe recommended 22 grains of 2400 (of course, this was in the 1940's).
Clive Barker wrote a book about this cartridge, "Shooting the .43 Spanish Rolling Block", which I believe you may still be able to find online.
Cartridge wise, this is closest to the 44-77 Remington (basically same cartridge with a .446 slug).

[Tom Herman]

Ken,

Here you go: http://www.levergunscommunity.com/viewtopic.php?t=27410
Graphs on the hoof for everyone to see...
And more information on smokeless powder pressures referenced to in the above link: http://www.levergunscommunity.com/vi...an+Bell#p97915

[brstevns]

Interesting reading. Looks as if both 5477 and 4198 might be the way to go.

[brstevns]

Has anyone tried the American Powder Company black substitute , with the Lyman 370 gr bullet ?

[KenH]

Tom: Thanks for the link - those pressure curves look like they are hand drawn, but I do expect they're accurate. It looks as if 4759 is actually a lower pressure peak than is black powder with TrailBoss having the highest sharper pressure peak than any of them.

Ken H>

[Tom Herman]

Ken,

I concur...4759 is lower pressure than BP. And Trail Boss is simply not a wide choice!
The second link goes into the linearity of the pressure curve, and there the best performer was 4198.
It would be nice to be able to do pressure tests for cartridges with smaller loads of powder, such as .45-70 and others where you can expect about 60-80 grains of BP to be used.
Looks like I get to investigate strain gauges!

[marlinman93]

Phil Sharpe recommended 22 grains of 2400 (of course, this was in the 1940's).
Clive Barker wrote a book about this cartridge, "Shooting the .43 Spanish Rolling Block", which I believe you may still be able to find online.
Cartridge wise, this is closest to the 44-77 Remington (basically same cartridge with a .446 slug).

Never understood when 22 grains of 2400 was ever a good charge for the .43! I tried it in my .44-77 SBN Roller ad one shot was enough for me! It kicked the heck out of my shoulder, an I went home and pulled all the bullets! Reloaded all with 19.0 grs. and they were great!

[marlinman93]

Good luck finding 4759! It's out of production!

[brstevns]

Bump to post 32