Hi jasta, My experience is that if you start with a nice tight (QUALITY!!!!) component package, spring it correctly for the ammo your using, and make it work.... It's hard to get it to jam after that??? ...
....New condition guns with correct ammo work well, point well, and are a pleasure to shoot... I've found the same issues with AR's when using mixed components from different manufactures... all the little tuning tweaks that are factory performed, are now up to you! That's the down side of saving a buck... The knowledge, unattainable any other way, is priceless...
.... I love'em... can't get enough... There's much better guns now, after, most of /or more then, a century... but none are neater!!....
...best to all, til...lat'r...GT