does anyone have a load recipe for the 577-450 martini henry using trailboss powder?
i've got jamison brass on order
i also have win. WLR, cci 200, and fed. 210 primers on hand.
i'm thinking of using lee 400gr or 450gr cast bullits.
I'm looking for a sensilble load, as the rifle is marked "soft steel". i have 45/70's for heavy loads.
this is a family heirloom so i don't want to blow it up, just use it to shoot small deer at 100yds. or less.
thanks in advance.

I had the same fear with mine- not wanting to blow it up.
These guys have a sale on now.

http://www.centuryarms.biz/proddetail.asp?prod=AM1706

A 70% (of available case volume) load of Trailboss should come close to black powder pressure, but not power. Bullets are going to be the trick, of course make a chamber cast and see what size bullets it needs. Likely you'll end up having to paper patch some up to size. Those guns really do work best with black powder though.

Toss this question to the guys at

http://britishmilitariaforums.yuku.com/

Some people did try trailboss in 577-450 - and the results were iffy pressure-wise. While it seems to perform as advertised in smaller cases like 45-70, things seems to get tricky with larger case capacity. Don't forget trail boss essentially is a bulky powder with a relatively fast burning rate - a pistol powder. I wouldn't go there...

Rocky mountain cartridge makes a reduced capacity 577-450 case that has about the same case capacity as a 45-90 WCF. Imagine a turned case with a straight cylindrical hole from the case mouth straight down. They don't have it listed on their price sheet, but they do make them. This will allow you to make much more uniform loads. If you decide to load BLACK, which is what these cases were originally intended for, you will be pleasantly surprised as well. Call Hodgden for a lead on Trailboss load data. I can't believe the number of people who ask for unusual load data and don't go straight to the powder manufacturer for recommendations.
Good luck


www.rockymountaincartridge.com/

hodgden recommends 70% to 100% case capacity, that seemed a bit much to me. So i posted the question to see if anyone has tried it.
As for black powder I cannot get it. nobody sells it anywhere near me (nearest is possibly 5-6 hrs drive) and i don't want to deal with dangerous goods shipping!!!

See if you can find Spring 2008 double gun journal. This has an article by Sherman Bell who gets a 577/450 shooting with trail boss and cast bullets. He does say that he's not tested pressures, so be cautious. He also talks of having success shooting undersized (458 dia) cast bullets. Bob

i read a couple of his articles in the double gun journal, he doesn't mention a charge weight. But in the pictures he has a target with 35grs. and a 340gr gas checked bullet. I checked my cases and got approx. 30grs with a 400gr bullet (@100%)
I charged some cases with 22grs.(approx 70%) and tried them quickly at the range. Got 1 1/4" group at 50yds. Not much recoil, very little soot on 2 out of 5 cases, nothing unusual about the fired cases or rifle.
Next i'm going to try a softer 400gr hollow base bullet (when the mould shows up) and see what speed they're clocking.

I don't shoot the 577/450 but I have had good results using BP substitutes in other cartridge loadings. I've settled on American Pioneer because of it's lack of fouling and it's vol per/vol loading to BP. But there are others.
Is that a possibility or are those sub. powders just as tough to get as real BP.

bp substitute powders seem to be just as difficult to get.
My 400gr hollow base mould finally showed up. i casted some 20-1 bullets. they seem to be approx. .462 diameter, i'll have to load some up when i get a chance and try them. they should fit the bore better than the .458 bullets.

Sorry for the late reply, I just saw this thread for the first time. This is the load data my Dad developed and I helped him record.

The following data was from a 577/450 Martin Henry long lever rifle out of Napal. Is has a 33" barrel with a fine/shiny bore. Brass was Jamison, primer CCI#200 (large rifle), powder IMR Trail Boss, projectile 500gr. lead round nose with no gas check. The velocities were measured by a Shooting Chrony F1 Master Chronograph about 15 ft. from the muzzle and are the average of three shots. The most accurate loads were between 8 and 10 grains. There were no pressure signs in any of the loads and they felt very mild to shoot. Ambient air temp and humidity was not recorded but it was a pleasant spring day so lets say low to mid 70s and maybe 50%(?) humidity. Use this data at your own discretion as no claims of safety are being made here considering the age of these rifles but in our rifle there was no evidence to suggest that these loads were not completely safe.

8.0 gr 617 fps
8.5 gr 662 fps
9.0 gr 680 fps
9.5 gr 782 fps
10.0 gr 789 fps
10.5 gr 792 fps
11.0 gr 825 fps
11.5 gr 822 fps
12.0 gr 840 fps