45 Colt Rifle/Pistol Combo Loads

[gpurp]

I'm thinking about getting a Blackhawk to complement my 1894 24" CB both in 45 Colt. Assuming I start with a common load such as a 250gr SWC over 9gr Unique (~900 fps in a pistol) then what kind of velocity should I expect out of a 24" rifle barrel?

 

[ArchAngelCD]

It's hard to tell what the velocity will be from a 24" barrel compared to a 5.5" barrel, especially with a low pressure handgun cartridge. In some cases you can actually lose velocity when you push a low pressure cartridge through a very long barrel. The powder used will also effect the results you get, the faster the powder more the chance of gaining nothing from the longer barrel. I'm not saying for sure it will be slower but it's possible.

Now, if we were talking about a .357 Magnum that would be a completely different matter.

 

[Gryffydd]

It's all about the powder burn speeds. I pick up almost 600fps with a 250gr LSWC in my 20" 1894 over my 5.5" Blackhawk. But that's with H110. With Unique and a 24" barrel I'd guess maybe 100-200 fps, but that's just a guess.

 

[USSR]

gpurp,

Think about moving to a slower powder to take advantage of the rifle's potential for higher velocity. I would suggest 2400 or 4227.

Don

 

[Kosh75287]

Alliant HERCO is, for all reasonable intents and purposes, a slightly slower-burning UNIQUE. At equal pressures in any rifle barrel length, I would expect slightly higher velocities from Herco. That said, it isn't so slow-burning that it won't burn completely in a 6" barrel (I've never gotten 2400 to burn completely in barrels less than 7 1/2"). Unburned powder from short barrels makes for lots of flash & noise at the muzzle, but not much else. Blue Dot or AA#7 might make for a decent compromise between the two barrel lengths.