6.5 Grendel

[Shane Lindsey]

Just picked up a Sanders armory 6.5 Grendel upper. Took it to the range and it would not shoot better than about 5 MOA with Hornady 123gr Black or the 123gr SST.

It seems a little undergassed, as it would not consistently lock or feed. Will this affect accuracy as well? Can usually diagnose a bolt gun. Not new to ARs (issued) but never had to trouble shoot them, jsut handed them to the armorers.

 

[WanderingGoatie]

What did the spent brass look like?

 

[Roughrice]

It sounds like its under gassed.
Sometimes it could be the gas block alignment...causing the port to be slightly closed
Sometimes it could be the gas port (too small)...but Sanders is usually set up correctly...unless a drilling bur is blocking the port.
Sometimes it could be the buffer/spring combination... if it was being used with a different barrel/cartridge configuration.
Even the bolt lugs fitting tight in the barrel extension may cause a delayed release.
I've hand cycled a tight one before 40-50 times, slamming it into battery to "break-in" the lug abatement.