From: bartb@hpfcla.fc.hp.com (Bart Bobbitt)
Subject: Re: M1 Chamber insert
Organization: Hewlett-Packard Fort Collins Site

There've been a couple of sources for 'em over the years.  I don't recommend
using them.  When they were first used by the military to convert 30 cal. M1s
to 7.62mm NATO, too many of 'em were pulled out by the case being extracted.
I've seen a couple of the civilian versions come out, too.

Accuracy is not good when they're used.  That extra half-inch of bullet
jump to the lands is not good.  And some .308/7.62 new cases would not quite
chamber easily in these modified .30-06 chambers.  Seems the chamber diameter
at the 7.62 case's shoulder was too small to allow easy chambering of the
round.

BB