McDoone

Best description I could come up with. Had my gunsmith mill a flat on the feed ramp, put a custom made big headed screw (10/32) then trimmed everything off I didn't want. One improvement I didn't think of at the time was to make the flat deep enough and the button wide enough to engage the side of the frame in the support part of the barrel. And then cut flats on the side of the button to match. Glue of any type (that I've tried) isn't forever. Got a much larger custom screw ready to go when I feel the need. No doubt there are supported barrels out there that have enough material to start with, but I've never seen any.

I have a button installed on the feed ramp of supported barrel or a filler in the frame on conventional non supported designs. The idea is to fill the space above the magazine to the point that as soon as the slide hits the back of the cartridge it’s too late for the round to screw up. Gave me pretty near perfect function on my single stack fo 15 years and a lot of rounds. And would with with any and all magazines. (2 or 3 malfunctions a year, all attributable to reloads) Just did my double stack with a button, perfect so far, but not proved out long term. (About 15000 rounds only). On my double stacks all mags had to have the lips shortened. None would release the 1.255 rounds otherwise. But it seems to work fine up to 1.275 (depending on the width of the bullet meplat.) These loa numbers are for .40S&W throated. I was going for 10mm length to get the 10,000 lb reduction in pressure the books show with IPSC loads.