How much neck tension do you aim for on your small frame semi autos?

[Winny94]

Conventional wisdom said .004-.005 neck tension to prevent bullet setback, but ive been reading and talking to a lot of people lately who are running closer to .002-.003.

I wanted to survey the group. What cartridge do you run, how many do you keep in the mag, and what tension to you aim for to prevent setback?

 

[spife7980]

I just use a plain jane sizer die for my semis with lc and fc brass and it’s whatever the expander ball leaves em. .002-.003 I think. Don’t shoot them that much but my first time out with them I took the calipers and couldn’t tell that the 8, 9 or 10th rounds in the mag were set back or after getting so violently chambered so I haven’t futzed with thinking about it since. I haven’t measured with a 20 round mag.

I think a heavy buffer and adj gas block does as much for limiting how jossled around they get and mitigating harsh recoil pulses as anything.

 

[Skunkworx]

For my SPR I don’t worry about it. My sizer will set neck tension to .009 tension with the expander ball removed. For me, it works well. I don’t have setback and don’t need to worry about crimping.

 

[clcustom1911]

.003 tension plus Lee Factory Crimp Die. My AR's aren't and won't be for precision. 2-3 MOA accuracy is my standard for my AR ammo.

 

[Cascade Hemi]

.003 with well annealed cases.

 

[AIAW]

.003 or so, plus factory crimp. Never had an issue there. Too little of course can be an issue in an AR specifically.

I did have a batch of 77g Nosler CC's a bit back that I put a little "extra" crimp on that shot a lot better than the "regular" crimped ones. Not sure if that was extra pressure building which caused a different barrel timing/harmonic or what, but it happened to work out well.