22XX Probes, Bolts, Breeches, O-Ring Question's...

I'm building up several 22XX guns, pistols and rifles and I'm having the same problem on all of them.

My bolts are binding in the breeches and during assembly I mount the barrel in the breech and close the bolt and my o-rings are showing through the breech transfer port hole, is this how it should be? Locking the bolt handle down is tight, and although its better than slop and the bolt opening during firing, I think its just a little too tight.

I have a whole collection of bolts, probes from various suppliers and I usually find I have to mix and match probes and handles to get smooth operation. I have particular problems with .177 probes in stainless from SD Custom design which as I understand are made by Don Cochran. I'm not trying to slate anybodys work here, just understand the problem. The problem is probably the idiot putting them together! ;^)
I really want to use the stainless bolts as they a beautifully made and look really good on my new blue and stainless .177 target pistol.

It could of course be my stainless breech causing the problem. Also I'm ripping up O-rings despite checking for and cleaning up burrs in the barrel. I put this down to the o-ring entering the barrel, instead of sealing around the face of it, and hitching in the transfer port hole.

Any ideas guys? Thanks