bolt not locking back on last shot

[pappy42]

I think I might have figured this out. I put in some "twang busters" (which I put in all my lowers) and I think this is allowing my buffer to bottom out too soon. When I pull the slide back manually the bolt just barely goes far enough to catch. I took the twang buster out and now have more than a 1/4 inch. Will have to wait and see if it fixes the problem.

Let us know if this works for you. Might save the next shooter.