leadman
04-28-2010, 06:16 PM
I have an Encore with a 7mm Rem barrel that is giving me problems.
Most of the brass will enter the chamber and be anywhere from flush with the end of the barrel to .003" below the end of the chamber with the extractor removed. There is also .004" gap between the end of the barrel and the breech.
Some brass when fired shows a small bulge in front of the belt so I suspect the barrel is chambered too deep. The shoulders on new brass do not touch the shoulder area in the chamber either so I end up with a very thin spot in front of the belt. This has lead to case seperations on second firings.
I have fireformed the brass with 15 grains of Unique and COW with a wax plug and is a little better, but the brass still thins in front of the belt.
I think I know what is wrong but need a dimension of how deep the recess in the chamber should be for the belt.
Is there also a SAAMI spec for the distance from the belt to the shoulder? I looked at headspace gauges by these do not include the shoulder area on them, as headspace is supposed to be controled by the belt.
The headspace in this barrel seems to be controlled by the extractor as it holds the case back enough so it will fire. This is why you can fire 45ACP in a 45 Win mag Contender barrel.
Does anyone have a belted mag headspace gauge to give me the dimension from?
Most of the brass will enter the chamber and be anywhere from flush with the end of the barrel to .003" below the end of the chamber with the extractor removed. There is also .004" gap between the end of the barrel and the breech.
Some brass when fired shows a small bulge in front of the belt so I suspect the barrel is chambered too deep. The shoulders on new brass do not touch the shoulder area in the chamber either so I end up with a very thin spot in front of the belt. This has lead to case seperations on second firings.
I have fireformed the brass with 15 grains of Unique and COW with a wax plug and is a little better, but the brass still thins in front of the belt.
I think I know what is wrong but need a dimension of how deep the recess in the chamber should be for the belt.
Is there also a SAAMI spec for the distance from the belt to the shoulder? I looked at headspace gauges by these do not include the shoulder area on them, as headspace is supposed to be controled by the belt.
The headspace in this barrel seems to be controlled by the extractor as it holds the case back enough so it will fire. This is why you can fire 45ACP in a 45 Win mag Contender barrel.
Does anyone have a belted mag headspace gauge to give me the dimension from?