Sized my Brass with Forster NM die, will it work in a bolt gun?

[Lrdchaos]

I bought a set of Forster Dies off the Forum and didn't realize that they were the N.M dies. After talking with Forster they said that the NM die basically sets the shoulder back .003 for a tighter chamber. Will that affect anything in a Bolt gun? Do I need to trash the brass I sized and just start with new brass? Thanks in advance


Per Forster---National Match 308 Winchester sizes the brass to minimum chamber dimensions, as Match rifles have chambers cut to minimum dimensions rather than the middle of the allowable range for size.

 

[MagnumManiac]

I bought a set of Forster Dies off the Forum and didn't realize that they were the N.M dies. After talking with Forster they said that the NM die basically sets the shoulder back .003 for a tighter chamber. Will that affect anything in a Bolt gun? Do I need to trash the brass I sized and just start with new brass? Thanks in advance


Per Forster---National Match 308 Winchester sizes the brass to minimum chamber dimensions, as Match rifles have chambers cut to minimum dimensions rather than the middle of the allowable range for size.

What method did you use to size your brass, die just touching shell holder, press camming over or something completely different?
All this matters, none of those above methods will have the same amount of shoulder bump.
Can you measure your fired brass dimensions?
If you cannot, then you can only go by how tight/loose they feel when you chamber one of the sized cases in your rifle.
This is what I suggest you do, fire 10 cases, have the die 1 turn out from touching shell holder, size a case, clean and try to close the bolt on it. If it's too tight, repeat above but turn the die in 1/16 of a turn at a time until a case has a slight resistance to closing the bolt, then turn the die an additional 1/32 of a turn. The bolt should close easily at this point, tighten the lock nut and set screw. Done.

Hope this helps.

Cheers.
gun)

 

[Lrdchaos]

I had the ram all the way up and screwed the die in until it touched the shell holder. The rifle is being built as we speak. I will wait to size anymore until I have the rifle in hand. I was going to just size the brass and have it ready to develop a load when the rifle arrived.

 

[FearNoWind]

The only way to know how your dies affect your brass is to run a couple of pieces of fired brass (some fired in your new rifle, some fired in an off the shelf rifle) through a thorough reloading routine, load a bullet without primer, remove the firing pin and see how if feeds and how it seats itself in the chamber. You may find that brass fired in your custom chamber need nothing more than a shoulder bump; or you may find that they need full length resizing. No two rifles are ever the same, even those that are chambered with the same reamer. Commercial rifle chambers are generally a bit sloppy and will accept just about anything in their particular caliber you might want to chamber; within reason, of course. Custom built rifles are usually built to closer tolerances and have tighter chambers. A round fired in a standard commercial hunting rifle often will not chamber in a custom made chamber, even with full length resizing. I'd suggest you be patient and wait until you have the rifle.