Someone posted a pic of a Storm Lake extended barrel for the G31 not too long ago. Just got back from the range, testing my new KKM barrel. It's a G35 357 Sig conversion barrel that dropped right into the G31 and performed perfectly.
Easiest way to put it is that the equipment is more accurate than the operator Good sight picture, good trigger control, it's dead on. And, that Underwood flying out the barrel feels like everything you imagine 357 Sig should be.
I have been really tempted to do this with my G23. I currently use it with a G32 barrel. However, I would love an extended barrel in it. It shouldn't cause any carry issues, but I would get G31 velocities. An extended barrel with ports would also be cool.
An EDC S&W M&P 357SIG. Ten Glocks sold. NRA life member.
"If lethal force is warranted and appropriate under the circumstances, the" (defender) "must shoot until the threat ceases." Pinizzotto, Kern, and Davis, FBI Academy.
I use a 5" belly band that allows a custom fit similar to a shoulder holster or low-chest carry for driving or hiking underneath the vest I wear almost constantly. No carry problems whatsoever. Also have an IWB holster long enough to fit a full-size 1911 and the G31 with extended barrel fits quite comfortably.