Due to the length of the enlarged portion at the muzzle, you really shouldn't try to tightly fit a solid bushing to a Series 70 barrel. You can use a "loose" or ordnance spec bushing...usually. The reason is...due to the length of the "bulge" the barrel may not drop in time for the upper barrel lugs to get clear of the slide. Damage to both barrel and slide lugs can result.
The collett bushing fingers did break on occasion, and the reason was simple. The owners used a wrench to turn the bushings with the slide in full battery instead of backing the slide up a half inch and turning the bushings easily. Those fingers weren't designed to take rotational forces. Had those owners consistently read and adhered to the instructions in the owners' manual, Colt would possibly or maybe probably still be using the system.
With the only exception that I'm aware of being the OEM Norinco barrels, all modern 1911 barrels have an enlarged portion near the muzzle that is shorter than the old Series 70 Accurizer barrel. That allows for more closely fitted bushings while still allowing for linkdown clearance.
The Series 70 system was actually a pretty ingenious design and it worked well. As the "bulge" entered the bushing, it forced the ringers into tight contact in the slide bore AND gripped the barrel tightly., giving similar results of a closely fitted bushing. In those pistols that also had adequate fit vertically at the rear of the barrel, they'd often deliver near match-grade accuracy right out of the box, averging sub 2-inch groups at 50 yards from the bags with good ammo. One in particular tyhat I handled shot into just over an inch with handloaded 200 grain SWCs.