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James K · January 21, 2014, 08:23 PM

Here is a good description of what is involved. Go down below the illustrations and read carefully what is said about the GO and NO-GO gauges.

http://www.forsterproducts.com/store.asp?pid=24834

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Bart, .015" is greater than the difference between the Go and Field gauge lengths, and it is hard to imagine any case stretching that much without some signs of a problem. If you mean that the case was neck sized and kept stretching that much each firing, something is very wrong; in ten firings, it would stretch .15" and in 100 firings 1.5", an impossibility.

As to the amount of setback in so many rounds, that would depend on the material in the bolt and receiver, the hardness of each, the size of the lugs, the bearing surface, the caliber of the rifle, the pressure, the area of the inside of the cartridge base, etc. Take a Winchester Model 70. One chambered for .22 Hornet would probably last almost forever in terms of headspace, while the same model in .375 H&H would probably not last even half of your 5000 rounds.

In target rifles that are fired a lot, headspace is rarely a problem; the barrel will be shot out and replaced long before headspace becomes excessive, and headspace (to a point) can be reset when a new barrel is installed.

Jim

January 21, 2014, 08:23 PM	#16
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Here is a good description of what is involved. Go down below the illustrations and read carefully what is said about the GO and NO-GO gauges. http://www.forsterproducts.com/store.asp?pid=24834 -------------- Bart, .015" is greater than the difference between the Go and Field gauge lengths, and it is hard to imagine any case stretching that much without some signs of a problem. If you mean that the case was neck sized and kept stretching that much each firing, something is very wrong; in ten firings, it would stretch .15" and in 100 firings 1.5", an impossibility. As to the amount of setback in so many rounds, that would depend on the material in the bolt and receiver, the hardness of each, the size of the lugs, the bearing surface, the caliber of the rifle, the pressure, the area of the inside of the cartridge base, etc. Take a Winchester Model 70. One chambered for .22 Hornet would probably last almost forever in terms of headspace, while the same model in .375 H&H would probably not last even half of your 5000 rounds. In target rifles that are fired a lot, headspace is rarely a problem; the barrel will be shot out and replaced long before headspace becomes excessive, and headspace (to a point) can be reset when a new barrel is installed. Jim