[Rotting]

Don't even know what a bolt buffer block is, so I can't imagine that I have one installed (purchased brand new, doubt it was pre-installed).

The old bolt catch I had was pretty worn down, so a steel replacement was put in. Was set up with shims. Thicker on the left, thinner on the right, not enough to compromise the action of it though.

With an empty mag in, the bolt doesn't catch (checked to ensure it wasn't in dry-fire mode), goes back to the forward position. If I press on the bottom half of the bolt catch, it will catch again. You said the spring isn't strong enough, but I don't know where to get a replacement bolt catch spring that would be stronger.

Looking at the bolt carrier, the area where the catch engages looks really worn/rounded. Not sure if this is anything that can be fixed or not.