help with selecting powder

[petep]

I have a lyman trade rifle (1 in 48) and a plains pistol. I have used fffg in both...I really have to for the pistol, but can use ffg opr fffg in the rifle.

recently I purchased a 1 in 28" green mountain barrel and the warranty says:

Disclaimer: Green Mountain muzzleloading barrels in .50, .54, and .58 calibers have been designed specifically for use with Black Powder FFg, Pyrodex 'RS', or Pyrodex 'Select' only. The .50 caliber Long Range Hunter 1:28" fast-twist barrels are designed to shoot heavy lead conicals or saboted bullets only and will not shoot a patched round ball. Use Blackpowder FFFg or Pyrodex P for .32, .36, .40 and .45 caliber round ball only. Do not use miracle lubes or bore seasoning agents on your rifle barrel. DO NOT USE SMOKELESS POWDER!!


does anyone use fffg powder in these fast twist barrels...can I?

 

[Swampman]

I only use 2F for blank charges, it's too dirty and inefficent for live fire.

 

[beefbone]

You didn't say what caliber you've got those barrels in. What caliber(s) are you dealing with?

The faster twist barrels can handle just as much pressure as the slow barrels, but the greater mass and friction of the elongated bullets causes more pressure to build than is the case with round balls. Using FFg makes the problem more critical.

I've been pondering which granulation to use in my .45 carbine with minie balls, but - in .50 and up - would only use FFg with any kind of strong charge pushing a heavy slug.

 

[Zonie]

I notice that in the Lyman Black Powder Handbook (2nd ed) they list pressures and velocities for the fast twist barrels using ONLY 2Fg, RS and Select for heavy sabots or slugs.
Green Mountains warnings seem to go along with this line of thinking.

IMO, in a fast twist barrel with a heavy slug or sabot, the powder has to cause the bullet to not only accelerate rapidly in a linear direction, but in a rotational direction as well. Because of this, the bullet is more of an obstruction in these barrels than it would be in a slow twist barrel.

If it were me, I would go along with the powders recommended by the barrel maker.

By the way, when shooting the 330 and 400 grain slugs in my .40 cal Schuetzen I would't dream of using 3Fg powder and the fouling from the 2Fg powder is actually not bad at all.
zonie

 

[petep]

thank you all..it is a 50 cal...and I suppose the last post is dead on...the mfg must suggest 2g in their fast twist barrel for a good reason.

 

[beefbone]

Thanks for adding your comments.

I screwed up in my posting, saying that FFg makes the pressure problem more critical. Meant to say FFFg would create the problem.

 

[Mad Professor]

I only use 2F for blank charges, it's too dirty and inefficent for live fire.

I think not. FFFg is fine for PRB but will give much greater pressures when shooting conicals that the 1-28 barrel was made for.

Below is 5 shots at 50 yds 1-28 50 cal GM barrel 80 gr GOEX FFg, wonder wad, 385 gr buffalo bullet. Sighted as is it's about right on at 80-5 yds.

 

[Dave Rosenthal]

I tend to agree with you. I use 3Fg Goex in my trade rifle with a 1 in 48 twist.

From the looks of that target with one ragged hole, I'd keep on doing what you're doing, that's for sure :bow: .

Aint BP fun? All of the variables to overcome and experiment with!

Dave