Two part question. Two different guns. First, I have a 7mm STW in a remington sendaro(I know, not aa pistol, but it looks like most of the experts are here). It eats up brass after about 3 or 4 reloads, cracking the necks down both sides. I want to start annealing the necks to alleviate this. Here is my question. After resizing and trimming, I then anneal and squelch the brass in water. Do I need to resize again before reloading? Does the heat expand the neck further?

Second question. This is a stupid one, but I have never done it because all of my other guns are repeaters. Can I set up a rcbs 308 win fl die to neck size only? And how? I have a pretty good idea, but I need to know for sure. How far down the neck do you resize?

Thanks Guys

Chad,

Heat expands all metals. Your dies may be over working your brass. Ideally, you want the neck/shoulder junction making contact at exactly the same time as the forward edge of the belt. Chances of this happening is rare, so, the next best scenario would be to have the contact occur prior to the belt.

Smoke (magic marker)the neck of your fired case and the forward edge of the belt. Back your sizing die off 1 turn. Run a fired case up in the die and have a look. Provided there is no contact with the belt at this point, advance the die until the sizing mark on the neck falls just short of the neck/shoulder junction. Try the brass in the rifle and see if you feel resistance when you close the bolt. If so, smoke the neck/shoulder junction and belt area again and rechamber the brass. Look to see where the contact is occuring. Again, it is prefered to have the brass make contact at the neck/shoulder junction rather than contact at the belt.

Your sizing dies can be off in comparison with your chamber. Gunsmiths sometimes have to trim die bodies or clear belt areas to author a match between the dies and the chamber. You need to explore the relationship that exists between your fired cases, your dies and your chamber. You need to know what your dies are doing and you need to know at what point to stop sizing. Over sizing or over working the brass splits necks and shortens the life of the brass.

Annealing: I have always annealed the necks prior to sizing. Others may do it differently. Place a board over a pan of cold water. Pass a propane torch around the neck/shoulder area of the brass. When the brass starts to glow, knock it off into the pan of water. Clean, trim, size and load.

As far as neck sizing with the FL die, don't. Die manufacturers make neck sizing dies specifically for this purpose. The manufacturers are not going to let you neck size with full length dies, no sir, that is why they sell those dies seperately. If you use the full length die to size the neck, by the time you size the neck to where you need it, it's too late, the brass is sized. Use a neck sizing die.

I hope this helps. Good luck,

Malm