solution to 6Br in Tubb 2K ?

[JFM33]

I recently picked up a Snider barrel chambered in 6Br for my Tubb 2K and it is leaving the brass looking like a belted Magnum,with a mild load of 30grs/Rl15 and Sierra 107's.
I measured how far a go headspace gauge sticks out of the chamber and subtracted the depth of the bolt to bolt face and came up with 18 thousands.
Has anyone fixed this problem?
Thanks John

 

[DickE]

I don't really know what you are saying. you may want to rephrase it. Sound like what you are trying to say is you have .018(eighteen thousands) of headspace?

If that is true, you have about .014-.017 too much.

 

[JFM33]

Actually the headspace looks ok on fired brass.
I think the problem is the space between the barrel and the coned bolt face.
I know some of my other guns have around 10 thousands interference fit in the same area.
I was thinking I could move the shoulder around 15 thousands ,bringing the barrel closer to the bolt face.If I do that I would also have to run a reamer to get the proper headspace.I just don't know what the minimum space could be between the barrel and boltface and if that would fix the problem?
I belive the unsupported area of the case is too much and is causing the case to blow out when fired,so much so it leaves a ring around the case rim like a shouldered magnum which appeares unsafe?
thanks John

 

[FatBoy]

I think you're on the right track. I'm not familiar with the T2K threading or shoulder. With that in mind pushing the chamber and threads forward to reduce the unsupported area of the case is probably a good idea. My match rifles have about .0005" between the conical lugs and the barrel. Small enough that I can feel a grain of Varget crushing when I close on it. My field rifle have a bit more, maybe .0010" to allow for some grit. .0018" on a case known for high pressure seems like too much to me.

 

[Dusty Stevens]

That gun if your measurements are correct is a danger to you and bystanders. Im sure tubb would want that back to have whoever chambered it fix it before the lawyers get involved. Do not shoot it anymore and when its fixed do not reuse that brass.

 

[JFM33]

Thanks Chris for letting me know how close your bolt and barrel are. It will give me some reference to shoot for.
Dusty thanks for your concerns,that brass looks very close to failure hence my Quest for a solution.
Thanks John