I have tried gauge mates in several variations and they seem to work very well. The little data I have seen has not shown much velocity decrease, usually along the lines of a reduced shot charge in an overbored barrel.
The problem is that tehy will not, as a general rule, fit in a 2-1/2 inch gun. They are not generally as useful as they would seem. I have a couple of older inexpensive guns with pits that I have lengthened the chamber in to 2-3/4" and then used the gauge mates.
If there was a commercial source for the chamber sleeves, they would be simple to install for anyone with the equipment. They would go in like the headspace repair rings that Brownell's has/had. The same piloted tool would bore for them.
|