Historical: I have a Chiappa M422, the lower is an ATI billet aluminum with CMMR lower parts kit. I've replaced the hand guard with an inexpensive free-float rail. I've recently acquired a billet upper, with all the sweet stuff installed. I went ahead and swapped the poly upper out with the new one, installed the barrel and torqued it.
Everything fits, the bolt ~seems~ to extend out about 1/8 in from the lower, but it easily closes and snugs up. From external inspection, it's a perfect match (except the color of the upper is a shade off). I had to make one minor adjustment to the bolt: there are 2 notches along the side that seemed to have been stamped, and the steel had slight bulges along the edge. A micrometer showed a couple 100's of a MM off, easily corrected with a file. The bolt slid in the receiver smoothly, better than the poly upper.
I've test cycled several mags worth through the rifle, the only problem I experienced was the rounds seem to 'snap' out of the chamber crisper than the old upper, and a few got flung across the room, lost forever. I've NOT fired the rifle yet.
My question: Is that a concern about the headspace? It is using the SAME bolt and barrel, the big change is in the container that holds them together. The upper is actually a thicker, stronger one then I've seen on other (read PSA) rifles.
Second Question: Could this be an ideal target for a .22WMR conversion, due to the excessively stronger configuration? And if so, besides modifications to the mags, what needs to be done?
Everything fits, the bolt ~seems~ to extend out about 1/8 in from the lower, but it easily closes and snugs up. From external inspection, it's a perfect match (except the color of the upper is a shade off). I had to make one minor adjustment to the bolt: there are 2 notches along the side that seemed to have been stamped, and the steel had slight bulges along the edge. A micrometer showed a couple 100's of a MM off, easily corrected with a file. The bolt slid in the receiver smoothly, better than the poly upper.
I've test cycled several mags worth through the rifle, the only problem I experienced was the rounds seem to 'snap' out of the chamber crisper than the old upper, and a few got flung across the room, lost forever. I've NOT fired the rifle yet.
My question: Is that a concern about the headspace? It is using the SAME bolt and barrel, the big change is in the container that holds them together. The upper is actually a thicker, stronger one then I've seen on other (read PSA) rifles.
Second Question: Could this be an ideal target for a .22WMR conversion, due to the excessively stronger configuration? And if so, besides modifications to the mags, what needs to be done?
