Not necessarly , I just had a customer in who’s rifle was doing this exact thing, everything mechanically and structurelly checked out ok
After a few questions he told me he cleaned the rifle after every shoot but was primarily shooting steel case ammo before this happened , now with brass ammo it’s having problems.
A bronze chamber brush chucked into a cordless drill on low speed and a healthy soaking of kroil removed all the residual laquor that was built up in the chamber that regular cleaning wasn’t removing , after the initial slow pass the brush and kroil began lifting the goo and it was obvious the chamber was caked in it
The rifle now functions flawlessly
This isn’t the first time I’ve seen this happen from steel case ammo, then a switch to brass case
I actually see it quite a bit from steel case ammo, that and eroded gas ports and gas blocks, I’ve seen gas blocks with holes burned right through them
Sometimes it’s the less obvious things that cause problems
