65Carcano Wrote:Could you go into more detail about what makes your PSA upper sketchy? I have the same one, and wondering if mine is sketchy too. I noticed my PSA bolt has much looser tolerances and is far easier to assemble/disassemble than the Ruger 5.56 bolt, which I suppose is nice for cleaning but a bit alarming otherwise. I haven't measured bolt faces etc though.
If the head space is good with your PSA bolt, then you could check the bolts firing pin hole. Spec is .625 to .70..I prefer no more than .645 ..
If your firing pin protrusion passes as VASCAR2 recommended, then you would need pin gauges to check the 3 bores in the bolt carrier..The best fit between the bolt shoulder O.D. and support bore I.D. in the bolt carrier for accuracy will have no more than .001 difference. If you have .004 or more difference, then your bolt is going to be sloppy in the bolt carrier which could effect accuracy and bolt life..
The other two bores have to do with gas efficiency and if your rifle is functioning reliably, I wouldn't concern myself with them for now..
If your gas rings are worn, then the bolt will assemble and disassemble easier..Some bolts will have shallower cuts in the bolt gas ring channel, preventing the rings from compressing as much compared to other bolts. As long as the BCG passes the gas ring check you should be good...
Always check your firing pins tip for any cratering or chips. Be sure the firing pin slides easily in the bolt..
Check the cam pin to bolt cam pin hole for side to side play. If there is a lot of play then you would need pin gauges and a taper pin gauge to see if the cam pin hole is too big or if the bolt is stretching. A common sign for a stretched bolt is if the firing pin will not slide freely in the bolt.. A bolt that will pass a taper pin gauge is a sign the bolt is about to break..