Lack of grouping

[Baldpate]

Need a little help!
I just finished a build with the 18" Monster barrel on a rig running a standard open (non-adjustable) low profile gas block, standard carbine buffer and spring and I cannot get a consistent group at a 100 yards with Hornady 123gr SST factory loads..? I'm getting a variance of up to or above 6" difference in point of impact. I do have an ejection angle of about 4:30-5:00. I pulled the bolt and mated the carrier to the gas tube with no resistance what so ever and I have a snug dimpled gas block with no signs of leakage. Oh yeah, I'm running a Hybrid 46 suppressor on the front end. Ideas?

Thanks in advance.

Looks like the Blackout will accompany me for Wednesdays hog hunt!!

[Bigs28]

First, i would check scope mount. Take it off and re mount it to spec. Second i would try a different ammo. Eldm works well out of my rifle and sst does not. I would also try with the suppressor off. And check to make sure muzzle break is on tight if your suppressor connects to a muzzle device.

[Texas]

Something is loose. Mount, rings, ect. What scope are you using? Shooting from a rest? What type of rest?

[Jeepster18_88]

Neither one of my Grendels will shoot the SST factory load. One shoots over 12" 9 shot group (BCA) and the other shoots about 6-8" (Diamondback). Both uppers shoot Wolf at about 1/3 or less size and the Hornady ELD-M at 1/4 or less size. The last break in group with the ELD-M in the Diamondback was around an inch followed by the SST still shooting around 7". Oddly enough, the ELD-M bullets that I dug out the clay bank retained a little more weight than the SST so it should make a decent hog round. I'd try some different ammo because some other people have had the same experience as I have with it. Some guns like it and others hate it, and no one has been able to narrow down a particular brand of barrel that will consistently shoot it.

[VASCAR2]

Try shooting without the suppressor, it is possible the threaded barrel is not concentric with the bore which might cause the suppressor to be out of alignment.