Welded Barrels
Weldin'em up and cuttin'em back to fit...Ahhh! Those were the days!
Bad ol' days! Those "Hard-Fit" barrels are the nuts, and I understand...though I don't know...yet...that the Kart EZ-Fit system is
the double-nuts for the hobbyist.
Part two:
Bushing to slide and barrel to bushing fit is one critical area that needs to
be addressed a little further, lest the first-timer think that all he needs to do is make it good'n'tight. The barrel tilts...up into battery/lockup...and down
into unlock/linkdown. If the bushing to barrel fit causes the barrel to be forcibly locked in the vertical plane, it creates "Barrel Spring" and actually
bends the barrel in the middle. Not a good thing. The bushing needs to be clearanced a bit at the inside rear area...and sometimes a little at the front
bottom...to allow the barrel to vertically lock in the slide without requiring force.
Then, there's the matter of linkdown clearance. Most production, ordnance-spec pistols come with barrels that have a slight flare toward the muzzle end.
This allosw for a closer fit with the bushing, and still provide adequate clearance behind the flare for the barrel to unlock. This flare is sometimes
referred to as the "Fitting Pad." The diffrence in the two diameters typically runst to about .006 inch or so...and if your hard-fit barrel doesn't have it,
you'll have to put it there, or go with a bushingless system. This is accomplished with a barrel turning fixture and a lathe. It's also helpful to
scrape a little clearancing provision at the rear bottom edge of the bushing,
just for a little added insurance that the barrel will fall into bed.
And THEN there's the little matter of adjusting the barrel stop surface and
frame bridge so that the link won't be stressed and stretched by the barrel stopping on the bridge...and so that the barrel lugs won't be peened, rolled, or sheared by the slide if the barrel hits the stop surface before it's completely unlocked, AND THEN there's the matter of selecting the correct link to match the lower lug's dimensions and geometry...and it goes on and on....don't it?