Take a shot and the breach opens ?

[Virginia Hessler]

Hi
This just started happening today.
I should give a little history on this gun. I bought a DH action and a set of VH barrels 12 guage, put them together smoked them and have a nice tight on face gun. While I was at it I replaced the wear block on the barrels.
I shoot skeet with this and have shot over 1,000 rounds through it and it worked perfectly.
Today every shot the breach opened. I took out the bolt and it looks fine no damage. I lightly filed the wear block and made sure the bolt was making full contact. Haven't retried it yet but I don't think I improved anything, I really didn't see anything wrong.
Any thoughts ? I'm sure I'm not the first person this has had happen.

Thank you, Tom

[charlie cleveland]

something is not letting the locking lug be seated its full lentgh thus letting the gun come open..the fix mite be as easy as cleaning and oiling the lug...charlie

[Brian Dudley]

How does the top lever spring feel?

[Virginia Hessler]

Thanks for the replys
I have removed and cleaned and inspected the locking lug ( I called it the bolt but I probably used the wrong term ).
The top spring is strong, I'm pretty sure that is not the problem.

I used a little inletting black on the wear block and found the bolt engaged about half way up the little ramp when closed. I filed the block down slightly to give it a little more engagement will try it out tomorrow.
Thanks, Tom