Match reamer neck size 308

[mr45man]

Was wondering
In a custom chambered match grade barrel target gun.
Said to have been chambered no turn/tight neck/ .002 clearance ,
What should fired 308 brass measure at the neck?

 

[Keith Glasscock]

*If* you are using the brass that the reamer was designed for, the brass will come out tight enough that a new bullet will just barely get through the neck. In some cases, the necks can come out the same size as they were before firing.

If you change brass, all bets are off. For example, shooting Win brass in a chamber designed for Federal will give you ~.010" expansion of the neck.

I would suggest that you either get the actual dimensions of the reamer, or cast the chamber to determine the neck diameter. With that information, you can get brass the right size, and avoid a bad experience (gun blows up in your face) from trying to feed it ammo with too large of necks.

 

[XTR]

Yea, there are huge differences in neck thickness between Win-Lapua-Federal

I have a no turn tight neck barrel for WW It is reamed at .339, that will give you real problems if you try to shoot FGMM

My current target rifle is set up at a pretty standard .342, that chambers everything and in my F-TR loads I get brass failure from case heads or primer pockets before I ever split a neck.

 

[Shynloco]

Was wondering
In a custom chambered match grade barrel target gun.
Said to have been chambered no turn/tight neck/ .002 clearance ,
What should fired 308 brass measure at the neck?

mr45man,
I wholeheartedly agree with what Busdriver says about using the wrong brass. Light years difference between Federal and Lapua. And if you have a concern about the sizing, might I suggest you consider giving Dave Kiff (Pacific Tool & Gauge) a call (541-826-5808) and discuss your particulars with him. I recently ordered a new .308 reamer from him and wasn't sure about the best size to go with considering the platform I was using. The man knows and is very helpful which is why experienced shooters even turn to him for help. Good luck with that new setup.

Alex