Variance OAL?

[dimmepe]

Hand loading for IPSC - what variance in OAL is considered material?

I don't consider myself a "consistently accurate" shooter..... Yet. But want all the advantages I can get plus I'm anal LOL....

Mixed brass
Cam pro 124 RN
Sample of 10 from box of 100
Target OAL = 1.120
Longest = 1.1205 variance = +0.0005
Shortest = 1.1155 variance = (0.0045)
Average variance = 0.0025

Would this be considered immaterial? Again I would not consider myself a consistent shooter yet.

I measure both OAL and powder every 10th load and eyeball every case for powder prior to seating bullet. I feel my quality control is pretty good? I haven't had any issues with ammo yet.

Thank you.

 

[RePete]

Don't sweat it, the proof is at the target, as long as you do your part.

 

[4n2t0]

With mixed brass that variance in OAL is insignificant. Just make sure you leave a little room for small variances when determining OAL (e.g. My CZ barrel allows 1.105 with my bullet of choice so I load to 1.095).

 

[tjhaile]

If your rounds function correctly, make power factor, and are accurate, then there is no problem. .005" extreme spread in OAL is perfectly normal.

 

[Ganderite]

I would say your variation is excellent QC.

The variation is not a big issue, so long as the long ones don't bind in the mag or hit the rifling.

 

[bigedp51]

With mixed range pickup brass not trimmed to the same length and seating and crimping in the same operation the OAL will vary.

If you want less variance in the OAL make sure the seater plug is a good fit to your bullet and seat and crimp in separate operations.

But at short pistol range you would be lucky if you see a improvement with mixed range pickup brass.