I have a Glock 20 that I use for backcountry purposes. I have a .357 Sig conversion barrel for it, purchased from Lone Wolf Dist. While I really like shooting both calibers, the problem I have with using the .357 barrel is that it misfeeds every few rounds. When I remove the slide, it looks like the Gen 3 spring that came with the .357 barrel has unseated itself. I’ve tried the G20 Gen 4 spring, but it seems too strong for the .357 and won’t completely cycle. Im thinking of buying a G31 Gen 4 spring to use in the G20 with the .357 barrel, and am aware of the possibility of using the wrong spring while shooting 10mm, but I would like to have a reliable .357 setup. I just don’t know if the dimensions are the same, and if it will work. while I can gamble with $16, I’d rather get something with a high confidence of success. My other option would be to buy the G31.