As mentioned several posts above—page 15, June of ’25-- I bulged the barrel on a most-cherished pin gun, one of the few custom guns I’ve done for myself:

With a little time between paying jobs, I need to get this done. But like everyone else, I hadda wait for it to get fitted in to the schedule. OK, maybe I didn’t wait as long as some people. But I need to hurry through it. With a small hole gage I was able to determine the diameter of the bulge (.010 per side) and find the center of it along the bore axis. Honestly I came this close to just using it as-is….. probably would have been fine for the rest of my days. But when this thing shows up somewhere in 200 years I want it to be right.
Let the heartbreak begin. With the barrel bulged into the comp’s gooseneck, there is no threading off of the comp. There is no boring out of the barrel at the bulge to relieve the interference. Theoretically I could, but I determined the best approach was to cut it all off at the middle of the bulge.
Boo-hoo……thirty-five years ago I went to a lot of trouble to make the comp and gooseneck all once piece, from a 2” bar of Crucible 4140. Now, two pieces.

Gage pins confirm the measurements I took with the small hole gage. .019-.020 oversized in the barrel.
The threaded stub came out pretty easily with an easy-out; at that exact spot the thread was to some extent tapered, in my favor (because of the bulge.).

Why is the hole in the comp, where the guide rod goes, so large? The recoil spring plunger telescopes into it so the recoil spring does not have to be cut off short to accommodate the shortened slide. Short springs are unhappy, long ones are happy and live longer for it.
Well…. if I need a new barrel some day for the OACP, this one will work. Shortened to the right length, the bulge will be completely gone.
While I’m at it, I will smooth out the topography that has worn into the breech face after tens of thousands of pin loads. It’s only a couple thou but it can eventually be an impediment to feeding.
I didn’t get quite to the bottom, but what’s left looks worse than it is—about .0002, two-tenths of a thousandth.
