Shoulder set back for AR

dan158

New member
I measured my once fired brass from the 204. The reading was 1.660.. After re-sized the brass was 1.650.. Should I try to set the shoulder back less to squeeze out more accuracy or will this affect how the AR functions as in reliability.. Thanks.. Dan
 
Are my new redding dies out of specs?? To get those numbers with the redding die I have a gap between the shell holder and the bottom of the die of .0035... That seems like a big gap there.. Dan
 
I wouldn't worry about the gap if you're getting the bump that you want. Greg's only recommending .004-.005 less than what you're doing now.
 
Greg is on the money IMO. 4 to 5 thousandths is enough set back. Don't worry about the gap under your die.
 
And your getting way to much head space with .010 set back, keep pushing them back .010 every time and you will start getting case head separation... I wouldn't be pushing them back more than .002 or .003 MAX... JMO
 
Originally Posted By: dan158Are my new redding dies out of specs?? To get those numbers with the redding die I have a gap between the shell holder and the bottom of the die of .0035... That seems like a big gap there.. Dan

The gap is not excessive. You are sizing the heads down far enough that you won't be getting the belted magnum look. I routinely grind a shell holder down 0.010 for all my variants for different chambers and believe me that gap you have is minor.

Greg
 
I tried that and the brass chambered fine in my AR.. Now I tried it in my bolt action 204 and the bolt is real tight to close...A once fired brass in the bolt and the measurement is 1.670.. So what is going on now?? I am not getting true FLS now to fit any chamber? Thanks for the schooling.. Dan
 
Originally Posted By: dan158I tried that and the brass chambered fine in my AR.. Now I tried it in my bolt action 204 and the bolt is real tight to close...A once fired brass in the bolt and the measurement is 1.670.. So what is going on now?? I am not getting true FLS now to fit any chamber? Thanks for the schooling.. Dan

No you are still FL sizing. You are probably within about 0.0015 of perfect for the bolt gun. An AR routinely will have a shoulder that is a bit shorter than measured as the bolt unlocking and movement will often cause a variation of as much as 0.003. That isn't the back of the case holding things up it's the shoulder height.

You could turn your die in that extra 0.001 and be GTG.

Greg
 
Redding Competition Shell Holders will help with setting the die with no gap. I like to have different F.L. Sizing dies set for my AR's and Bolt guns. That way I don't have to reset my dies every time.
 
Originally Posted By: yotekiller47Redding Competition Shell Holders will help with setting the die with no gap. I like to have different F.L. Sizing dies set for my AR's and Bolt guns. That way I don't have to reset my dies every time.

I have most of my guns heads spaced to be the same bolt/AR. But when they are not the same I use SKIPS SHIMS to make the quick adjustments.

Greg
 
Originally Posted By: yotekiller47Redding Competition Shell Holders will help with setting the die with no gap. I like to have different F.L. Sizing dies set for my AR's and Bolt guns. That way I don't have to reset my dies every time.

I bought a set of them a while back.. Just have to figure out where they are at.. Thanks you all for the input... Dan
 
Now I am thinking about modified cases from Hornady.. They wouldn't be that accurate then I would think because they are not fired formed for ones rifle to get distance to the lands.. Or help me think here about this.. Thank you all... Dan
 
Originally Posted By: dan158Now I am thinking about modified cases from Hornady.. They wouldn't be that accurate then I would think because they are not fired formed for ones rifle to get distance to the lands.. Or help me think here about this.. Thank you all... Dan

They might not be dead nuts but they will give you a close enough starting point after you learn how to use them correctly ...
 
Dan the modified cases is for measuring OAL to know how far to set your bullets off the rifling. The shoulder measurement is just for the brass from the rim to the shoulder, you can get a set of Hornady measures that allow you to measure a fired brass from your gun then set your full size die up to just set your shoulder back .001-.002 which decreases the stretch of the case during firing. But still allows the bolt to close easy.
 
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