Neck tension for a PRS rifle?

[JASON50CAL]

I normally shoot BR single shot rifles and just got my first PRS style rifle with savage 11 action, McCree presicion g5 chassis and a X-caliber barrel in 260 Rem. Last night I resized the brass and was running my mandrel in then to get the .002 neck tension I normally use on BR rigs and it dawned on me that I may need more since this is a mag fed rifle. Where should I start with neck tension for this style of rifle? Is .002 enough or do I need more?

 

[memilanuk]

Two thou is plenty. Three might be better, but if it shoots fine @ two, I'd run with it.

 

[rardoin]

I’ve shot a PRS style rifle in a F-class rules based match using mag feed only rifles. I shot a 6.5 and 6 Creedmoor with .0135” necks and 0.001” ‘neck tension’. They were seated about 0.008” shy of mag length. I measured the 8-10 round in the mag a couple of times and never saw a change in CBTO from the loaded measurement. I never worried about it after that. 0.002 is plenty unless your necks are extreeeemly thin.

 

[Hohn]

If you have more than .0015” neck tension, you are yielding the brass so neck tension is determined by metallurgy, not geometry. Harder neck, more tension; softer neck, less tension.

 

[Zero333]

Even 0.0015" is enough to endure a M1A trip from the magazine to the chamber with out crimp.

So in my opinion 0.0015" to 0.002" is more than enough to ensure no bullet movement.

 

[RegionRat]

I will suggest that you test for margin.

Take your current process and watch the length on a round from the bottom of the magazine for 4 shots, then drop 4 more on top and repeat.

This can be done for double or more the number of rounds you expect to run in a competition as a measure of margin.

If that doesn't set the bullet deeper, then you have a reference point for your current neck tension, if it fails, then you know you will have to test again after some process changes.

Unless the friction and grip pressure in your necks is the same, the sizing alone isn't the whole story.

 

[Rob01]

.002" of neck tension is fine. It's what I use in my rifles and have been shooting "PRS" matches before there was a PRS. LOL