Inconsistent case neck tension?

[Linefinder]

I tried something different today with my Redding bushing die. I tried very light tension, and not utilizing the expander ball. I don't neck turn or ream, since I was testing a load for a pdog rig. I could tell while seating the bullets that the neck tension ranged from almost none, to somewhat moderate.

When I clocked these loads,40 grain VMaxes in a .223 Rem) my ES was 165 fps. This same load, in a different rifle, has an ES of 14 fps.

Can inconsistant case neck tension cause this much variance?

Thanks,

Mike

 

[BarryL]

I dont know if it can cause THAT much but it can definatly contribute to a large ES and quite a bit of vertical on a target. If the brass has a few firings on it you may want to look at annealing. If your going for max accuracy you also want to turn your necks at least 75% clean.

 

[jb1000br]

LF - right on the edge is the worst place to be if you can't keep it consistant,via neck-turning) Better off running ~1.5-2thou NT which will nullify some slight differences in NT.

JB

 

[Linefinder]

Thanks, gents!

I don't shoot BR, but I do shoot a lot of pdogs. Normally, I keep 800 rounds each for a couple .223's, and around 300 for the 6mm. In the qtys I reload, I just can't quite bring myself to neck turn or ream cases.

In the past, I've used the Redding bushing .002 undersized, with the expander ball, and have obtained very good results. This time, I used a bushing only .001 under, and didn't use the expander. The runout numbers were very nice with the die set up in this manner, but, not nice enough to overcome the ES.

I think I learned my lesson.

Once again, I appreciate the comments.

Mike