Henry Rifle Forums

I'm still hoping to go to my club and try out the 44 mag and 45-70 at 300 yards but settled for 125 yards at my cabin this past weekend. The 12" barrel Big Boy was benched with only a front sand bag and maxed out at 5x on the scope. Not bad with the results but I'm thinking the groups could be tighter with a front and rear sand bag for better stability, use a balance beam and digital scale for each powder drop as well as weight each bullet. But I won't go that far... YET.

Which Big Boy has a 12" barrel. I think you meant the carbine model which is 16.5 maybe? You might give a Hornady xtp bullet a try with some 2400 or H110. Al

There's no official name for this one after this mod.

I can't call it a carbine because it's less than 16" and it's octagon barrel but does have the same receiver as the Big Boy. So I just call it the 12" barrel Big Boy.

This mod is completely legal in Canada and loads 5+1.

Iragveteran8888 calls it an Mare's Leg SBR

at 125 yards I'd be happy with that target .. .. I'm not familiar with IMR 4227 ... have you been able to run your rounds through a chrony .. .. I'd be most interested in the muzzle velocity

The last two chrony tests in -2*C it registered 1287 fps and in +20*C it registered 1350 fps.

Need to do another chrony test with our latest temperature average.

considering barrel length, that is a very respectful muzzle velocity

That's the where's waldo gun that disappears in the leaves! Nice shooting.

Nice shootin'!
With that short barrel powders like H110 will still be burning on the way out the door. If you check out my 44 chrono data. The difference between my Big Boy and 10.5" Ruger is about 300fps on most loads.

Does that Mare's leg have the same slow twist rate that the Big Boy's have?

Same twist.

With my reloads I'm able to get 1/2" groups at 50 yards.

Hey, that's a fine group at 125. I also chose IMR 4227 loading for my old 8 3/8" Blackhawk. It's a nice ball powder that fills the cartridge then compresses just a tad for consistent loads with a slightly slow burn. I used large pistol primers rather than the magnums that were touted for max loads.
Shooting the way yours do, whichever primers you use, I wouldn't change a thing.