I spoke with David from T/C this morning and had a long discussion about what he thought might have been the cause of the crack in my barrel.
After elimiting all the usual causes, he came to two different conclusions.
#1 it could have been build up of 777 and some of it piled up in front of the bullet. He said 777 will leave a clear coating of build up in the barrel after about 10-15 shoots. the gun will still load and shoot well but the build up is still there.

#2 it could have been bad tooling or metal fatigue

either way I'm glad to get the barrel back.

BIG.PAUL

Glad to here that you have it back... hopefully the new barrel will work a lifetime for you...

Not only am I glad to hear you have a new barrel but no one was injured by the old one... now you need to get out there and shoot.

x'2

I took the new barrel out last night. This barrel shots completely different, the original barrel would not group any tighter than 3 inches at 50-100 yards no matter what type load I put in it. I attibuted it to my shooting, but I was able to zero this barrel in with just 4 shots and the groups are within 1 inch at 50 and 100 yards.
Last night I was shooting 80g Of Premium select FFGwith a 370g T/C maxi-hunter and a winchester primer ( not 777 primer)switched over to max-balls and the group raised up an inch but was still very tight

See,Thompson Center came thru. I also got my $50.00 T/C rebate in the mail today,now we are both happy!

I had a friend just get back a barrel from TC from his Oncore, it would'nt group at all, 8-13" at best. Sent it in and found out the (rifiling) in the barrel was bad. He just received his new barrel the other day and is now shooting much tighter groups.

Paul - I hate to say this but I really doubt the problem was the T7. Build up or not - if the bullet loaded easily (got past the build up), then shooting it would not have caused a problem. Personally, having worked with all types of forgings and metal working, would have to say that that crack was in there when you got it and was missed during inspection. Or, it may have been a hair line crack that could have beeneasily missed or was just subsurface and your shooting it caused it to open up.
In any event, glad there was no injury to you or anyone else and that you got a new barrel and it is shooting good for you.

[quote]ORIGINAL: bronko22000

Paul - I hate to say this but I really doubt the problem was the T7. Build up or not - if the bullet loaded easily (got past the build up), then shooting it would not have caused a problem. Personally, having worked with all types of forgings and metal working, would have to say that that crack was in there when you got it and was missed during inspection. Or, it may have been a hair line crack that could have beeneasily missed or was just subsurface and your shooting it caused it to open up.


I was wondering when someone was gonna say that,i held back the first time and just went of cayugad's post.There's a lemon in all things madeyou just hope you don't get it.

Good luck with the new barrel.

Good to hear the manufacturer did the right thing!