also pick up your brass & study it, you can learn a lot from fired brass.....
if the extractor is slipping off the rim leaving slight marks you got a bad/weak extractor spring, if brass shows signs of gouging & sharp edges of brass, your bolt & carrier is opening too soon, or the brass may not be "shrinking" fast enuff to allow the action to function properly, which is caused by underpowered ammo, i belive you really do need to try the M193 ammo, that Winchester stuff you are using is loaded to minimun specs, military ammo is loaded "hot" for maximum perf., your Bushy is built to "mil-specs.", use "mil-spec" ammo & i belive your problems will dissapear..., AFTER you thouroghly clean the rifle, my Bushy loves the "mil-spec" ammo, never had a malfunction (except for Wolf) after i cleaned it & used GOOD ammo.........