AR-15 gas hole size for 6.8SPC

[dieselone]

I just finished an AR-15 with a custom 16" 6.8 barrel that I made from a blank. I used the mid-length handguards and a flat-top gas block. I drilled the gas hole to .104 (forget what # drill size that is), same as a 5.56 barrel I have in the shop. After some initial bugs; I was able to fire 3 rounds from a magazine without any problems. Didn't want to shoot too much in the yard, so, a week later, I took it to the range and couldn't get it to shoot 2 in a row. Now it appears to be short stroking. The bolt is catching the next round in the middle of the case and jamming. It seems like I might need a bigger gas hole. Anybody have info on the optimum size?

 

[10-96]

What ammo are you using? To get a bunch of Remington ammo shot up- I simply went with a lighter (carbine) buffer. As for hole size- sorry, can't help much there.

 

[sadsack]

Deiselone: Your gas port is really at the upper limit for a mid-lenth barrel. Your ammo (powder burning rate), as 10-96 suggested, may be the cause of your jams. You might check to see if your gas block is lined up with the port and sealing good (not leaking off gas pressure).