View Full Version : .308 Chamber Size

March 20, 2009, 10:17 AM

Any thoughts on the best chamber size for a .308?I have been advised on a range from .340-.342. My measured loaded rounds .338 which had me initially leaning to a .340 neck chamber. It seems this may be too tight for a field rifle where dust/dirt may find their way into an action?

I will mostly shoot reloads through this rifle but I would like to be able to feed it most anything and have it function.

Would I be disadvantaged going with a .342 chamber size?


March 20, 2009, 10:34 AM
You are talking about the chamber neck diameter.

The biggest problem wiht going with a tight chamber, especially in a 308 bolt gun that you want to be able to feed it most anything and have it function is that just a little bit thicker brass will cause problems. For example, if you were to fire ammo loaded in military brass, which has a thicker neck, you could cause an overpressure problem. If you intend to fire only sporting ammunition, and especially if you reload exclusively, then a tighter chamber neck diameter would be less of an issue.