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F T/R Competition Neck bushing?

DropinLead

Sergeant
Full Member
Minuteman
Feb 3, 2013
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Desert of Az.
I ask here sine those who shoot competition may have a different take than the general non competition shooter.

I turned the necks on my lapua brass after expanding then chamfered it. The neck diameter after expanding and turning was .337. I figured I'd use a .335 bushing to neck it down before seating the bullet. I did that then pressed in some 168 smk to exactly 2.8 oal with no powder or primer. The measured neck diameter with the bullet seated is .339. Did only 2 for measuring.

What is the effect of too much neck tension on accuracy/competition? Apparently I have .004 tension unless I expand and redneck them.
Thanks!
 
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Just because it says 337 doesn't mean that is what it will size necks too. What are the necks measuring AFTER using the 335 bushing? And if you have large chamber, sizing down more than 5 thous may cause issues. It did for me. My bushings are sizing 2 thous more than printed on bushing and runout is worse

Remember ideally you want to seat a couple bullets in your brass them measure necks. Then determine bushing size off that reading.

Most think less neck tension results in better bullet release and that is desirable in a competition rifle. I like my sized brass to be 2 thous smaller than my loaded round
 
Ok makes sense, I'll re-expand them, measure the bushing and use one that is 337 which should put me at .002 under.
 
The expander is my second to last step, last being chamfer/trim. This ensures the ID of the brass is as close to consistent as I can get it....the differences will be hardness, thickness, spring back, etc.
I have tried heavy and light neck tension, the most accurate is what I can do consistently.
I use a .340 and then a .336 for lapua, then expand to correct ID.
As mentioned, going more than .005" in one step will produce a neck OD smaller than the bushing, not to mention increase runout...at least for me it does.


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