I have a AR 15 in 300 BLK that is very finicky about ammo. About 75% of the loads I try will short cycle up until the point the load development process starts showing signs of pressure.
I can use 19.2 grains of Lil Gun with a130 grain bullet and everything is fine.
When I try H110 there isn't a single load that will cycle properly.
Cast boolits are out with any boolit, Weight or powder.
After playing around with this for a year I noticed the gas tube only goes half way into the key. (about 1 inch) Is that far enough?
Also how big should the gas port opening in the barrel be? Mine is 5/64"