Who here has gone through the head space correction procedure as described by Mike Bellm for Thompson Contenders?
How much difference will correcting whatever the factory spec is in terms of accuracy?

Thanks.

Dunno about accuracy difference on the Contender, never shot my Encore with the .008" headspace it had, .004" frame to barrel gap and another .004" recessed below the barrel face. I just formed a false shoulder on the .375H&H brass to decrease headspace to .001", it shoots ¾" groups afterwards and brass will last longer since that first firing doesn't stretch it.