Long and Happy Life
All I can get, Chuck...
This is gonna take a little time and space, but I'll keep it as short as I
can.
As long as the slide lugs are at about 100% engagement in the barrel slots,
and the gun will used for standard-pressure .45 ACP ammo, it'll
live long and prosper...assuming that the barrel lugs are in spec and
equalized in the load bearing...but you knew that already.
When I planned on "something more"...High pressures and/or heavy bullets, I wanted all the barrel lug in the slide recesses that I could get. Most of the time, I had what I had. If the height of the barrel lugs didn't engage at least 75% of the depth of the recess in the slide, I didn't use it for those applications, and stuck with more or less standard ammo.
Of course, that would vary a little on the #3 lug, since there was the issue
of the slide havin' enough clearance on that one to keep from beatin' up
the front corner...so I usually had to be happy with whatever I got on that lug. The #2 lug could get deeper and still allow for clearance.
If I was determined to use the gun for that kinda thing...a toy mainly, but
also for a defensive gun to be carried into "Bear Country", I'd start by
fitting the barrel slots to engage the slide lugs at 100%...and check the
barrel lugs for depth in the slide. If it wasn't what I wanted, I'd have the
lugs welded and light in with a file until I got the barrel fairly centered up in the slide again, assemble the gun and see if it would go to battery...and
cut a little off the tops until it would go.
Then I'd remove metal until the barrel was centered vertically, blue the tops
of the lugs, and remove metal from the lugs until they just cleared...
remove another .010 inch from the front lug, and about .005 from the swcond. Blue the lugs again and test-fire the gun with a light load and spring to check for signs of interference at the front corners...and adjust accordingly with emery cloth in small increments. At that point, I lightly broke the corners of the barrel and slide lugs at 45 degrees and tested the gun with full-power loads. If there was no sign of rolling or flanging, I had a gun that would withstand a good amount of use with the heavy stuff.
Final step was lappin' it all in with Du Pont Rubbing compound...we didn't
have J&B then...and it was cheap and worked prety well.
Much of it was probably unnecessary, and may not have added enough life to the guns to make it worth the effort...but I had time on my hands and
liked to do the work...so I did the work...mainly for my own use, but I did a few for other guys too, and it seemed to work out pretty well.
Cheers!
Tuner