[MOUNTAIN WILLIAM]

My next project will be to have a stainless 16" full octagon barrel installed on a stainless Marlin 1895 in 45/70 but I have no idea as to what twist rate or how many grooves would be preferable. It's unlikely that I will ever shoot any cast bullets through it, the ammo would be factory fodder primarily, with some Buffalo Bore, Double Taps, CorBons and Garrett's tossed in for good measure. I'll get around to reloading for it, eventually.
Here is the list of available twist rates and grooves, any comments and opinions are welcome. Thanks in advance!

1-8" (6 Groove)

1-10" (6 Groove)

1-14" (6 & 8 Groove)

1-18" (8 Groove)

1-22" (6 Groove)

 

[Wade505]

Well sir, the standard has been 1 in 22" for this caliber. The faster twists may be of some help if you were shooting uber fast heavy/long bullets, but I'd doubt that would help that much in stablizing 400 gr. or so projectiles as to the bearing surface being standard as well. If I were building your weapon I would put a 1 in 22" tube in place....

Wade

 

[moofy07]

The standard for barrels from Marlin for 45-70s is 1:20" Right Hand twist with Ballard type rifling with 6 grooves.
Hope this helps.

 

[MOUNTAIN WILLIAM]

I hadn't thought to ask what type of rifling was involved with my project. I'll find out if there are any options in that respect. Thanks for the help guys!

 

[80hp]

Just make that barrel 16 1/2". That way you won't anger the Feds. If its 15.999, they won't have sympathy for you.
M.

 

[MOUNTAIN WILLIAM]

Lol, but of course. We all know who's measuring equipment they will be using.