New 6.5 Grendel Stove Piping

[McFireFighter]

Here are the specs.

Aero Precision Upper and Lower
Timney Trigger
Midwest BCG
Shilen barrel with headspaced bolt
Midwest Handguard
Luth-AR Milspec rifle length gas tube and buffer
Aero Precision rifle length gas tube and block

About every test group had a stove pipe.

First thought is I'm not bumping the shoulders back far enough. Seems like they are not loading in smoothly. Would that cause it? To much friction? I'm going to first try that.

Let me tell you the 123 Scenar load shot off the chart today. One hole 5 shot group. The 129 Nosler Accubond Long Range shot about an inch or so. Maybe 1-1/2". Going to rerun that test and the Scenar. Just wish the Scenar acted like the A-Max on game. My 5.56 AR with the 69 Tipped Matchking is also scary accurate. Can't wait for the groundhogs.

[LRRPF52]

Stove pipe malfunctions are when the ejected brass does not fully clear the ejection port, and sticks out the side at a 90 degree angle usually.

Most common cause is under-gassing from misaligned gas block.

Measure your gas block alignment from barrel shoulder to the gas port, and make sure the gas block port is centered over the barrel's gas port.

[McFireFighter]

I'll do that. I set it in the dimple on the barrel and tightened down. Loads are not loading into chamber as well as they should. Will fix that. If I can find a load that shoots like the Scenar for hunting, I'll be very happy.

[McFireFighter]

To make a long story short the barrel didn't have the gas block dimple. That's my fault. By measurement it looked good. But it wasn't. I think that and sizing the brass a tad more will make it hum. Thanks.

[LRRPF52]

Change one thing at a time. Mis-aligned gas blocks are a common problem for short-stroking.

[McFireFighter]

Good idea. Thanks again for the help. I know there is supposed to be a gap between the gas block and shoulder of the barrel. Small but a gap none the less. What seems like the best flow is with a larger gap than the norm with other barrels I've installed. As long as it functions I'm happy.

[LRRPF52]

Good idea. Thanks again for the help. I know there is supposed to be a gap between the gas block and shoulder of the barrel. Small but a gap none the less. What seems like the best flow is with a larger gap than the norm with other barrels I've installed. As long as it functions I'm happy.

Sometimes that is true, and sometimes it isn't. It all depends on the distance from the barrel shoulder to the gas port, and the rear edge of the gas block to the port inside the gas block.

I have some where the gas block mates up to the barrel shoulder for alignment, and others where there has to be stand off for the handguard cap we don't use anymore.

[McFireFighter]

Very un-scientific way of finding best flow like I said was blow down barrel with a spent round in the chamber. I locked it down at what felt and sounded like the clearest path. Loading up some loads tonight. Not sure if it vibrated closing off the port as the problem seemed to get worse. It now has great flow and should be fine assuming it's locked down good. I will let you know how it goes tomorrow.