I have just reslugged my barrel three times. There were no “soft” areas when drifting the slugs so hopefully there are no barrel bulges, there are no rings that I can see. All three slugs mic’d out at .4495, what the barrel slugged out previously.

The 200 gn PFP bullets mic out at .4515, as do the commercially cast 230 gn LRN.

When I cast the 100 200 gn SWC I mic’d 10 of them at .4515 (2), .452 (7) and .4525 (1). I do not have a .451 bullet sizing die and I decided to use them unsized.

After slugging the barrel and mic’ing the results I started to run the remaining cast SWC (abt 40 remaining as I discarded some I didn’t like the look of) through my micrometer and found several in the first 20 that mic’d out at .4545. This may be why a few of the bullets caught in the seating and crimping dies and others didn’t?

Is it possible they were oversized enough to “ stick” while engaging the rifling causing pressures to rise as the slide started out of battery? My understanding is that the bullet should be exiting the muzzle before the slide starts to move.