Heads Up On Green Mountain Barrel Problem

[Semisane]

Hey guys. I saw a post in the Percussion Rifles section of The Muzzleloading Forum by a guy who bought a GM .54, 1"x32, 1:70 replacement barrel for his Renegade from the Log Cabin Shop, Lodi, OH. During cleanup following his first range session he discovered the nipple was M6X75 thread, and the breech plug was threaded for the standard TC 1/4 X 28 nipple.

I just got finished checking the .54 GM barrel I bought last month from Track Of The Wolf, AND FOUND THE SAME THING. The nipple starts to wobble in the threads after the first 1/4 turn out. Not a good thing. I just finished sending a notice to TOW and GM.

 

[sabotloader]

Semi

I have both of these nipples on hand and sometimes that can be a curse - if they get mixed up. The two thread patters are very simular(I can not tell them apart by looking at them).

I do not think it is just GM - as the results are the same with a TC barrel.

It seems to me that the M6X75 will thread down into the 1/4x28 very easily and in my case it did and it was snug - was not really loose. The reverse, in my case, was not the same - 1/4x28 nipple would not go down into the M6X75 easily - you could feel that something was wrong. I ended up using a tap to check both guns. When you put the correct tap in it screws down correctly when you put the M6 tap in the 1/4 you can feel the difference - it would not be difficult to ruin the the threads of either with a tap.

The only way i can tell the difference between the two nipples if they get mixed up is to thread them into a thread chaser of the correct diameter and thread pattern.

 

[cayuga]

Check with Green Mountain Barrel company... a couple years ago there was a problem with the nipple threads on some of the rifles. They had people send them back in and they put a shim of sorts in them and after that they worked fine. There was a notice on the GMB site where it listed what serial numbers would be effected. I had to mail back one of my barrels also. This might be the case, and if a company had a lot of the barrels on stock they might still have a defective barrel. So yes, I would mail GMB company.

 

[n8dawg6]

well, dang ... now i need to go check all mine