I have a 308 Armalite AR-10 and fired Federal Gold Match ammo. Can I neck size the brass only or is it required to full length size it. The fired cases seem to fit the chamber and the bolt closes on the few I checked.

Glen R I am assuming the federal brass was fired in another rifle probably a bolt gun, if so that might work, for target shooting only. For any "serious" purpose I would full length resize for absolute reliability. After you shoot some loads in your AR10 you will probably have to use the full length die. However you may be able to adjust the die "UP" so as not to set the shoulder back just enough to allow easy chambering without over working your brass. The only problem is that you might not resize the base of the ctg. enough to allow easy chambering. Get a Sinclair catalogue they have different type dies you can use.

Glenn

The nature of semiautos makes full length sizing necessary .

The semi auto's bolt dosen't have the "caming" power that you have with a bolt action . This means that a cartridge that may be a couple of thousanths of an inch over sized (too long or bulged body ) may not allow the bolt to lock in battery , yet allowing the rifle to fire ,
slamming the bolt rearward while the chamber pressure is still quite high . This Out of battery firing can be very damaging to rifle and shooter .

muck

Actually, this brass was initially fired in the same AR-10. I have previously read that brass had to be fully resized when shoot in a simi-auto. Placing the fired case in the chamber seemed to fit alright but the bolt closed a little tight. Am I correct that the case has to be fully resized and not just move the shoulder back a few thousandths. I certainly don't want to do anything dangerous but thought it might improve the accuracy.

Thanks for all the great help on this forum.

Glenn R You not only have to set the shoulder to where it will fit the chamber but reduce the diameter to fit the chamber as well. Muck is correct in that the camming power of the semi auto is not as high as the bolt. I have reloaded for several different 308 rifles, factory bbls, custom tight chambered bbls, M1A, and M1 Garand, and H&k 91's and a SR25. I have one set of dies that will allow a case fired in any rifle to be reloaded and fired in any rifle, but I have some resizing dies that are adjusted for one rifle to give long case life and easy chambering. I load 308 for my brother and have one set of dies set up for his rifle, sizing and seating, that I never change, I use them for only his rifle, that way the rounds always fit, I do not have to have his rifle here to check and see if they will chamber. It is better to be sure of positive functioning and have a little shorter brass life. You do definitely do not want an "out of battery experience" with your AR 10. Hope this helps.

[ 08-05-2002, 09:50: Message edited by: N E 450 No2 ]

It is very helpful and appreciated.

Thanks

full length resize, another problem i had, is the ammo may be to fat to work in the magazine correctly ,if only neck sized. This was in a m16 with stagered magazine.