View Full Version : 7mm08 Brass
phalford
06-26-2006, 07:03 AM
I keep reading that if I neck down .308 brass to 7mm08 Rem then I run the risk of a thick neck causing increased pressures.
1. If I want to compensate for this, should I use an Outside Neck Turner or reduce from the inside with a Neck Reamer.
2. If I want to buy new 7mm08 Rem brass, who makes it.
Rocky Raab
06-26-2006, 09:48 AM
First, a warm welcome to HuntChat.
The easy one first: Remington is the only maker of 7-08 brass that I know of. It's in current production so any good store or catalog should list it.
Now to the other question. Necking brass down does thicken the necks simply because the brass has to go somewhere. Outside neck turning is generally better, especially if the brass is thicker on one side than the other (which is more common than having it equal). Inside reaming will remove brass, but the reamer will simply ride the off-center hole, leaving you with thinner but still off-center necks.
Now the better news. For most factory rifles, you probably won't need to ream OR turn. Factory rifle chambers are pretty generous, and having a slightly thicker neck might even improve the cartridge fit.
Neck one .308 case down, seat a bullet in the empty, unprimed case and see if it will chamber easily. If you have a good caliper or micrometer, measure the diameter of a fired and unsized cases versus the dummy round with the bullet seated. If the dummy round is .002" smaller or less, you need to turn cases a bit. If it's .004" smaller, you're good to go.
HPBTMTCH
06-26-2006, 01:02 PM
phalford, I neck down .308 to .260, and the neck O.D. of the winchester .308 brass with a bullet seated is LESS than the factory remington .260 brass with a bullet seated. Do a check as rocky says and then to be sure all is okay, load a light load, fire it and see if you can push a 7mm bullet into the fired case with your fingers, if it drops right in, then there are no problems at all.
Ol` Joe
06-27-2006, 01:26 AM
Remington and Winchester both offer new 7-08 brass. You can also neck up 243 or 260 Rem. brass for the 7-08 The stretching of the case will thin the necks in place of necking down thickening them. I`ve necked 308 down for my 7-08s and so far haven`t had any that turned out too thick. I would go ahead and simply keep an eye on neck thickness. If they appear too thick I would outside turn them, I doubt you`ll have to though. Remember to measure them with a bullet seated when checking the necks. A seated bullet will expand them from a relaxed and sized dimention. The figure in the manuals is the max allowed.
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