Need advice on my AR load development

[Kangbeef]

Shooting a WOA 16" 1:7 spr barrel will a superlative arms agb
Loading 69gr smk, varget powder, cci 400s, new winchester brass annealed, 1.75 col seat 2.245 oal. Using xero1 chronograph
Should i choose the group #6 with the low es/ds and play with seating depths. 2nd option. Group 3 had one shoot that was higher in velocity which may caused it as a flyer.
I am loading with a beam scale and digital scale to double check weights. I am refining my loading techniques for more precise weights with what i have till i can snag up a rcbs chargemaster link. Practice makes perfect and love the chase of tite groups lol.

 

[simonp]

Personally I’d go with #3, I generally want the load that shoots the best at mag length in a gas gun. I’ve had one 16” WOA SPR barrel that had great numbers on the chrono but grouped poorly, tried loading shorter & didn’t improve the groups on target

 

[Kangbeef]

Personally I’d go with #3, I generally want the load that shoots the best at mag length in a gas gun. I’ve had one 16” WOA SPR barrel that had great numbers on the chrono but grouped poorly, tried loading shorter & didn’t improve the groups on target

My 69gr smk using TAC is like that as well. Looking for a temp stable powder like varget . May have to play around with both group loads. Edited

 

[straightshooter1]

My 69gr smk using TAC is like that as well. Looking for a temp stable powder and like varget due to clean burning. May have to play around with both group loads.

"clean burning" Varget??? When did that happen?

 

[Doom]

I would guess the one you would choose depends on what you are trying to achieve. You can pick the single digit SD or you can pick the one that is likely more accurate. It not likely that the "flyer" is due to velocity at 100yd.. If you didn't have chronograph data which would you choose?

OK, I'm being a little bit of a smart ass. Your 5 shot chronograph data really doesn't say much other than you may be having some inconsistencies in the brass prep and charging processes. It is hard to explain your "flyer" since it is over a 1/2" away from the 4 shot average POI which held nicely. What I can tell you about it is that it is very likely the bullet left the barrel on a different line of sight then the others. Could be be velocity/barrel harmonic related or shooter. If it were my group I would say that one is likely on me. The other group was stringing. I would pick # 3 and reshoot it. You might shoot the other group also and see what happens.

 

[JR1200W3]

There are some guns and loads that are really accurate and you can shoot a couple of 5 rd groups and make a semi-informed assessment of its accuracy. Same with 5rd Chrono data. When every 5rd group chrono's sub 5fps SDs it's probably still sub 10fps SDs across a 30rd group. But an AR-15 isn't one of those guns. And those groups aren't those types of groups either.

I'm not trying to be a butthole, but burning up Varget to shoot 1 to 1.5moa groups with 69gr bullets is not something I'd do. I would use Xterminator, maybe TAC, VVN135, H335, or Shooters World Tactical Rifle for a bullet that light. I definitely wouldn't worry about SDs in an AR that shoots lighter bullets that will likely struggle at the distances where SDs will start to matter. Your SDs in a gas gun will be challenged just based on the direct impingement gas system alone.

Don't base anything on those two groups yet. Shoot some different seating depths and shoot larger round counts groups or multiple 4x5's over several days for each load.

 

[Kangbeef]

Ok this is sound advice and will use it moving forward in the next step. Waiting on application for local club maybe next year or two so only go when invited. Will have plenty to do and load up till then. Thank you again for pointing in the right direction.