Anyone had accuracy issues with their JAKL?

I took my new 13.7" out on Sunday to get it sighted in with a 1-8 NX8 Nightforce. First 10-15 shots were fine, got it rough zero'd & gas settings correct at 50 and moved back to 100 to dial it in. Got it mostly where I wanted and then started shooting some steel. Accuracy dropped off the planet... at the end I couldn't hit a 10" plate from 100 yards with good handloads (that shoot 3/4" groups in some of my AR's).

I brought it home and cleaned the heck out of the barrel (had a ton of fouling in it for only shooting maybe 100 rounds). I checked the mount and scope (tight and GTG), I tried to wiggle the barrel and handguard, but they both seemed snug. I'm wondering if the barrel had developed a nasty burr at the gas port or something. That's about the only thing I can think of.

Any ideas?

@PalmettoStateArmory

-ZA

My 14.5 gets about 2 in groups off the bench. With a LaRue trigger. That’s with my std. 55gn hand loads. I am not sure if it is the long stroke piston is haveing any effect. I tend to get better accuracy with my DI guns.

@PalmettoStateArmory

Quick update:

Got the JAKL back out today to the range. After about 15 rounds, the gas port burr settled down and the rifle started shooting well. That means I was 15 shots short of not posting this thread after the first range session!

It loved my “blaster” load of mixed range brass, 55 Hornady SPBT and a stout dose of TAC! It was shooting that load into about 1” groups at 100 yards. That made me happy for sure!

This might be my softest shooting rifle when it’s suppressed!

I need to figure out a good way to memorize which way the gas block works, as I can’t ever seem to remember.