NOS Green Mountain Barrel

[Norman Brooks]

I was given a GM barrel. It is about 30 years old, 15/16" X 42" .50 Cal. and I thought the twist rate was 1 in 66", looking at the GM web say's 1 in 70". Did they change or have they always been 1 in 70". Thinking about posting it in the want ads for sale and want the correct info.

 

[Old Hawkeye]

I bought a GM drop in for a Hawken style rifle in 50 caliber about a year ago & it is stamped 1 in 66". At that same time their generic barrels were listed with a 1 in 70" twist. What they did 30 years ago is anybody's guess. Heck, it could be 1 in 60". Really doesn't matter. Just list it for sale stating it has the deep groove rifling with a slow twist suitable for PRB & that it could be any of the three & it is not the fast twist LRH barrel. They are super nice barrels & you won't have any trouble selling it, IMHO. BTW, are you sure there isn't a twist rate stamped on it somewhere? Mine is stamped on the bottom flat.

 

[Notchy Bob]

I had some old Muzzle Blasts magazines out, for the years 1973 and 1989. I didn't find any Green Mountain ads in the 1973 issues, and ads in the 1989 issues only list calibers and outside dimensions, with nothing about rate of twist. However, the one printed Track of the Wolf catalog I have on hand is #16, dated 2004. This shows a twist of 1 turn in 48 inches for .32, .36, and .40 calibers, 1 turn in 60 inches for .45 caliber, and 1 turn in 70 inches for .50, .54, and .58 calibers, including the Green Mountain "drop in" replacement barrels for T/C. An additional note in the catalog indicates "Grooves cut .010" to .012" deep, depending on caliber," and "Each barrel has eight lands and grooves."

I don't know when Green Mountain started making round-ball muzzleloading barrels, but I think it was some time in the mid to late seventies. I can't say for sure, but I think their rifling specs have remained consistent. I know the old Douglas barrels were generally 1 turn in 66", and I have a Fox Ridge Outfitters catalog for 1999 that shows the round-ball replacement barrels made by T/C for their own rifles had a 1:66 twist, also. I'm wondering if Old Hawkeye's barrel assembly might have been made by T/C rather than Green Mountain.

I am reasonably confident that your .50 caliber Green Mountain NOS barrel would have a 1:70 twist. I would expect to find that, if I were to buy it.

Best regards,

Notchy Bob

 

[Old Hawkeye]

I had some old Muzzle Blasts magazines out, for the years 1973 and 1989. I didn't find any Green Mountain ads in the 1973 issues, and ads in the 1989 issues only list calibers and outside dimensions, with nothing about rate of twist. However, the one printed Track of the Wolf catalog I have on hand is #16, dated 2004. This shows a twist of 1 turn in 48 inches for .32, .36, and .40 calibers, 1 turn in 60 inches for .45 caliber, and 1 turn in 70 inches for .50, .54, and .58 calibers, including the Green Mountain "drop in" replacement barrels for T/C. An additional note in the catalog indicates "Grooves cut .010" to .012" deep, depending on caliber," and "Each barrel has eight lands and grooves."

I don't know when Green Mountain started making round-ball muzzleloading barrels, but I think it was some time in the mid to late seventies. I can't say for sure, but I think their rifling specs have remained consistent. I know the old Douglas barrels were generally 1 turn in 66", and I have a Fox Ridge Outfitters catalog for 1999 that shows the round-ball replacement barrels made by T/C for their own rifles had a 1:66 twist, also. I'm wondering if Old Hawkeye's barrel assembly might have been made by T/C rather than Green Mountain.

I am reasonably confident that your .50 caliber Green Mountain NOS barrel would have a 1:70 twist. I would expect to find that, if I were to buy it.

Best regards,

Notchy Bob

I bought the barrel from Track of the Wolf & it was sold as a Green Mountain "drop in". It is stamped on the bottom flat with the Green Mountain logo, .50 CAL, 1/66. No other marks or stamps. All their "non-drop in" 50 cal barrels are listed @ TOTW as having a 1 in 70 twist. Go figure! Seems silly to have tooling for both 66 & 70, but they make barrels & I don't. BTW, it was made to fit a TC, but I did a couple simple modifications & fit it in an Investarm Hawken style rifle. Love that barrel!! Based on your catalog from 2004, the OP's barrel, if not a "drop in", could very well be a 1 in 70, but it hardly matters.

 

[Norman Brooks]

I will take a closer look and see if the twist rate is stamped, it does have the GM stamp and does have a slow twist.
Thanks...