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Bart B. · November 27, 2012, 08:26 PM

Got to thinking this out a day or so ago. I dawned on me that while I've often stated that an out of square receiver face relative to the chamber axis makes a high point on it the hard spot on the barrel's tenon shoulder. Pressure builds there as the barrel heats up and expands.

But what if the bore's not perfectly centered on a barrel that's perfectly fitted to a squared up receiver face? The heated up metal on its thick side's gonna expand more than the thin side. It'll bow around its thin side. And that'll make the muzzle axis move away from where it was when the barrel was at ambient temperature.

There are ways to find out if a barrel's thicker on one side of the bore than the other; spin it on perfect centers in a lathe and put a dial indicator on its mid point. Any wobble on the dial might be indicating out of balance.

Thoughts, comments and things I might not think about are welcomed.

November 27, 2012, 08:26 PM	#1
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Wandering Shots as Barrel Heats Up Got to thinking this out a day or so ago. I dawned on me that while I've often stated that an out of square receiver face relative to the chamber axis makes a high point on it the hard spot on the barrel's tenon shoulder. Pressure builds there as the barrel heats up and expands. But what if the bore's not perfectly centered on a barrel that's perfectly fitted to a squared up receiver face? The heated up metal on its thick side's gonna expand more than the thin side. It'll bow around its thin side. And that'll make the muzzle axis move away from where it was when the barrel was at ambient temperature. There are ways to find out if a barrel's thicker on one side of the bore than the other; spin it on perfect centers in a lathe and put a dial indicator on its mid point. Any wobble on the dial might be indicating out of balance. Thoughts, comments and things I might not think about are welcomed.