12-29-2021, 10:19 PM
How did you attach your barrel to the upper and did you ensure the upper receiver face is square?
Are you free-recoiling the rifle?
When I shoot lightweight AR-15s chambered in 6.5 Grendel, or AR-10s, I apply a lot of rear pressure into my chest with a very solid cheek-to-stock weld.
When I get on a bolt gun, it feels like cheating because I dont have to work anywhere near as hard to get tight groups.
Once I get down to 100gr or 90gr in the Grendel, then I dont have to apply as much rearward force and can shoot more like a .223 Rem.
Start with a square upper receiver face and a bedded barrel into the upper, or a really tight-fit barrel extension-to-upper fit.
Use less torque on a lightweight AR-15 barrel when tightening the nut closer to that 35-45ft-lbs range, and more torque on a heavier barrel going between 60-80ft-lbs.
Make sure the torque is equal/balanced on your optic mount cross bolts and ring fasteners.
Ive seen the best results with lightweight carbines when I shoot them bipod-folded on a softer bag with a rear soft bag that I can squeeze to get ideal POA, followed by bipod extended on a solid surface with rear bag.
Im talking about shooting multiple 16 and 18 lighter Grendels over the years, measured against multiple 20, 22, 24, and 28 Grendels from varying positions.
Sometimes, Ive just hit barrel/torque/rifle set-up combos that just hummed out of the gate.
Other times, they would shoot 1.5 MOA 5rd groups and send me head-scratching, but those were either lower price barrels or not-bedded barrels.
After bedding, the 1.5 guns would drop to no greater than .85 guns, no other variables.
PFs Krieger, Bartlein, Lilja, and Criterion pipes have been some of the most accurate barrels Ive ever shot, even compared to all the bolt guns Ive shot over the years.
I used to do final QC for a local rifle manufacturer taking a truck full of rifles to the range to accuracy-test each one, all of them being high-end bolt guns.
Ive seen a lot of different barrels and how they perform. Those rifles were either Krieger or LW from the 2009-2010 timeframe.
Krieger performance was night-and-day difference to the LW pipes. They almost always would shoot 3/4 to 1/2 MOA out of the gate. LWs, not so much.
Ive also independently tested complete uppers that PF sent out that customers said wouldnt shoot. I offered to buy one of them after printing 8+ round bug hole groups using PF 123gr SMK loads in Lapua brass. I couldnt believe how accurate they were. I had to look back at the ammo box to see how many rounds I fired. It was so unbelievable I wont even say how many, other than 8+.
I fully documented the test groups with witnesses and sent the photos and test targets back.
Another thing Ive noticed is that depending on the range gradient from shooting position to the targets, you will see tighter groups either in the top, middle, or bottom set of bulls on paper.
Some nuances to fundamentals with light guns:
This is determined by how your position is oriented to the target, and how naturally you settle into the position relative to how high each row of bulls are.
If youre too cramped or neck cranked while shooting the upper or bottom row, the groups will be larger.
Once you have the more ideal position, the groups will tighten-up. For me, thats often the 1st top row of bulls.
Once I depress the muzzle, I need more rear bag support, so if I dont build up that bag support to present the same tension, the groups will open.
This is most-true with the lighter weight guns, not as much of a problem with the heavier guns. Heavy rifles like to just settle into position well and are somewhat immune to these little quirks.
I like lightweight guns, so I try to get them to shoot as close to the heavier barrel rifles as possible.
Are you free-recoiling the rifle?
When I shoot lightweight AR-15s chambered in 6.5 Grendel, or AR-10s, I apply a lot of rear pressure into my chest with a very solid cheek-to-stock weld.
When I get on a bolt gun, it feels like cheating because I dont have to work anywhere near as hard to get tight groups.
Once I get down to 100gr or 90gr in the Grendel, then I dont have to apply as much rearward force and can shoot more like a .223 Rem.
Start with a square upper receiver face and a bedded barrel into the upper, or a really tight-fit barrel extension-to-upper fit.
Use less torque on a lightweight AR-15 barrel when tightening the nut closer to that 35-45ft-lbs range, and more torque on a heavier barrel going between 60-80ft-lbs.
Make sure the torque is equal/balanced on your optic mount cross bolts and ring fasteners.
Ive seen the best results with lightweight carbines when I shoot them bipod-folded on a softer bag with a rear soft bag that I can squeeze to get ideal POA, followed by bipod extended on a solid surface with rear bag.
Im talking about shooting multiple 16 and 18 lighter Grendels over the years, measured against multiple 20, 22, 24, and 28 Grendels from varying positions.
Sometimes, Ive just hit barrel/torque/rifle set-up combos that just hummed out of the gate.
Other times, they would shoot 1.5 MOA 5rd groups and send me head-scratching, but those were either lower price barrels or not-bedded barrels.
After bedding, the 1.5 guns would drop to no greater than .85 guns, no other variables.
PFs Krieger, Bartlein, Lilja, and Criterion pipes have been some of the most accurate barrels Ive ever shot, even compared to all the bolt guns Ive shot over the years.
I used to do final QC for a local rifle manufacturer taking a truck full of rifles to the range to accuracy-test each one, all of them being high-end bolt guns.
Ive seen a lot of different barrels and how they perform. Those rifles were either Krieger or LW from the 2009-2010 timeframe.
Krieger performance was night-and-day difference to the LW pipes. They almost always would shoot 3/4 to 1/2 MOA out of the gate. LWs, not so much.
Ive also independently tested complete uppers that PF sent out that customers said wouldnt shoot. I offered to buy one of them after printing 8+ round bug hole groups using PF 123gr SMK loads in Lapua brass. I couldnt believe how accurate they were. I had to look back at the ammo box to see how many rounds I fired. It was so unbelievable I wont even say how many, other than 8+.
I fully documented the test groups with witnesses and sent the photos and test targets back.
Another thing Ive noticed is that depending on the range gradient from shooting position to the targets, you will see tighter groups either in the top, middle, or bottom set of bulls on paper.
Some nuances to fundamentals with light guns:
This is determined by how your position is oriented to the target, and how naturally you settle into the position relative to how high each row of bulls are.
If youre too cramped or neck cranked while shooting the upper or bottom row, the groups will be larger.
Once you have the more ideal position, the groups will tighten-up. For me, thats often the 1st top row of bulls.
Once I depress the muzzle, I need more rear bag support, so if I dont build up that bag support to present the same tension, the groups will open.
This is most-true with the lighter weight guns, not as much of a problem with the heavier guns. Heavy rifles like to just settle into position well and are somewhat immune to these little quirks.
I like lightweight guns, so I try to get them to shoot as close to the heavier barrel rifles as possible.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com