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1/18/2013 9:08:07 AM EDT
without the availability of a range near by, does anyone have experience with the following:

I normally load up a 77gr SMK w. 23.6gr TAC (IIRC), this load is in a "fire formed" case that i bump back a few thousandths. If i were to do a full length resize so the rounds fit in any 223/556 chamber, will i lose my expected accuracy / velocity in the gun the load was tailored to? will i see an increase in pressure acting on the rifle?

were talking about a 1MOA load, so there werent any miracles in its development. I just want to know how resizing plays into load development.
1/18/2013 9:11:27 AM EDT
[#1]
FL resizing is the norm for ammo fired in an AR.



I have no problem loading ammo that shoots less than moa with FL cases in my AR.
1/18/2013 9:28:14 AM EDT
[#2]
Quoted:
FL resizing is the norm for ammo fired in an AR.

I have no problem loading ammo that shoots less than moa with FL cases in my AR.


but will it tweak my load, if i normally dont resize the case completely?

1/18/2013 9:41:09 AM EDT
[#3]
You are firing unsized cases in your AR?
1/18/2013 9:52:49 AM EDT
[#4]
Quoted:
You are firing unsized cases in your AR?


Im using a Full length resizing die, but im only bumping the case back a few thousandths... I would like to resize them fully but dont know if i will have to completely work up the load again as a result
1/18/2013 10:23:02 AM EDT
[#5]
Case volume will decrease slightly if you squeeze down on the body diameter, etc.  However, I don't think it is going to be noticed that much in the performance.  It is easy to check.  

1. do a few cases at your regular minimum bump size.
2. do a few cases at your max. full sizing.

Trim to same length.  Plug the flash holes.  Fill the cases to the rim with H2O.  Weigh them all full and empty.  Get the average difference in H20.
Quickload has a H20 in grains case volume parameter.  I can get you the predicted difference in velocity from that for weight of powder = same,
77 SMK bullet set at same COAL.

And, that difference will be conservative, because at peak chamber pressure both configurations will inflate out to the same chamber diameter.
1/18/2013 10:59:51 AM EDT
[#6]
Quoted:
Case volume will decrease slightly if you squeeze down on the body diameter, etc.  However, I don't think it is going to be noticed that much in the performance.  It is easy to check.  

1. do a few cases at your regular minimum bump size.
2. do a few cases at your max. full sizing.

Trim to same length.  Plug the flash holes.  Fill the cases to the rim with H2O.  Weigh them all full and empty.  Get the average difference in H20.
Quickload has a H20 in grains case volume parameter.  I can get you the predicted difference in velocity from that for weight of powder = same,
77 SMK bullet set at same COAL.

And, that difference will be conservative, because at peak chamber pressure both configurations will inflate out to the same chamber diameter.


that was my thoughts, will the reduction in case capacity matter much if its not a compressed load at this time?
1/18/2013 2:36:38 PM EDT
[#7]
You're fine.  Bump the shoulders about 0.002 inches shorter than the shortest brass from all your rifles.  The case capacity difference will hard to measure.

The quality of the bullet and the barrel will have a far larger influence.

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