Loads that work for AR

[Engel]

My AR is shooting all over the show. 4" grouping [4moa] That is using 55gr pmp, american eagle and 77gr loads.

Twist 1:8 18" barrel.

I have some 80gr .224 nosler I will need to shoot out so I need a load for that if anyone has quickload. Having said that it looks like 69gr seems to be the load for that twist.

I will first give the manufacturer a chance to remedy before I mention the brand. We are 3 friends having the same problem with the same gun. We also shoot 1mile plus so its not like we can't shoot.

I have all the reloading gear from progressive to single stage precision. Any views?

[A-R]

I think you can eliminate barrel twist rate from your list of likely causes. 1:8 should be good to stabilize anything up to 80gn cup/core bullets. Over-stabilization is a myth, except for very fragile bullets that can disintegrate from a too-fast spin.

At 4 MOA I would tend to rule out the load / accurate node as well. The difference between a fine-tuned load and an untuned one should be about 1 MOA or roundabout there. Using match bullets and proper load procedure and case prep, most SLR's should group under 2 MOA, and a typical AR15 should do better. For piston-driven SLR's add 1 MOA. These are rough ball-park numbers.

You should also check out all the accurising tricks for AR's and see where your's can be improved. The rubber band trick (for example) costs nothing. Also try single loading, to eliminate feed ramp damage. There are some more tricks.

If you can actually get the manufacturer to rectify, I can guess which one that may be...

Hope you get it sorted. Keep us informed please?

[SafeAction]

Not as informative as A-R's post.

http://www.gunsite.co.za/forums/show...aders-check-in Some info on what others used and results achieved.

http://www.gunsite.co.za/forums/show...ad-data-for-AR

[Hobbes]

Firearm: Daniel Defense DDM4V1 Light Weight
Twist: 1 in 7
Bullet: Frontier Range Master 52gn
Powder: S321
Charge: 24.5gn
OAL: 57mm
Velocity: +- 2850
Average Group: 1 MOA at 100m

I moved over to the range maser as a better quality alternative than the standard copper plated fare that does the rounds.

The bullet is a brass mono metal with a 3% lead content if memory serves. It is well made and has given me zero issues after about 3000 rounds downrange.

Something that may play in your favour is that being a mono metal bullet it is longer than a normal 55gn bullet due to being less dense.
You may also want to check concentricity of your loads.

As to your 80gn Nosler starting point. Not using the same bullet, but similar weight (77gn lapua scenar) I started to see pressure signs at 21gn of S321, so I would suggest doing what I did and start at 18gn of S321 and move up in quarter or half grain increments. Bullet was loaded to an OAL of 57mm.

[Engel]

Great!

Will load and test and also get some 69gr as well. Will start 18 with .5 increments and see what it does.