I have a Ruger American 22LR with laminate stock. It jams on feeding 3/10 times. One my friends has a ruger american synthetic that feeds reliably (be it with lucky13 25round or ruger 10round). I was confused, now I think I have it all figured out. The laminate stock has a magazine well that has been cut out by a router / wood mill. You can see the rounded indentation in the corners like pic related
Now the ruger mags dont mate with anything near the feed lips, they are held in 2 contact points one in the middle at the front, and again at the back. and the mounting points are round so the mags gan roll left and right until they hit the sides of the magwell. The greater the magwell is oversized the futher the mag can roll.
The top of the mag has the ejector and the feed ramp built into it, and the bolt slides over it very precisely, any roll and the bolt will strike it and jam against it rather than slide over it if it rolls around right/clockwise (rising the left side with the ejector into the path of the bolt). Or if it rolls around left/counter clockwise (rising the right side with the feed rampy bit) then the 22LR jams after feeding halfway and then the bolt crinkles the 22LR into a boomerang shape.
Basically, it is being a piece of crap for me, working smoothly sometimes and jam-o-matic other times until I figured it out. Changing or modifying the stock to more tightly hold the magazines in the EXACT right location will fix this. Don't know how, maybe build it up with araldite / cotton fiber, or solder, and then file that back until it fits tight and correctly aligned. That's my idea but don't know how I'm going to do that.
What 22LR feeds and ejects reliably and never jams not even once?
. Whereas the plastic stock has the magwell of plastic based on the size of the injection mold. The difference is the plastic stock magwell is precise sized due to the injection mold. The laminate stock magwell is roughshod because they just haphazardly buzz it out with some cnc router piece of crap I assume, and it cut it too big.