barrel to frame lug - dimensional changes

[maxtherabbit]

I've got a 645 slide assembly that I was hoping to run on my 4516-1. Unfortunately the barrel to frame lug on the 645 barrel is too wide. I measured it at .523" the 4516-1 barrel was something like .486". When did smith change this dimension?

The 645 barrel as well as my 1076 and 4516-1 all have the old style barrel hood (.342"ish) and the 45's fit into each other's bushings fine. Are there any third gens that have the wider barrel to frame lug?

 

[18DAI]

The 4516-1 is a third generation gun, while the 645 is a second generation pistol. You will need an early 4506 no dash slide to make it work. An early narrow hood 4566 top end may also work.

The early production 3rd gen guns had the narrow barrel hoods. All the late production 3rd gen guns had the wider barrel hoods. Revisions 3 and 4 IIRC. Hope this helps! Regards 18DAI

 

[maxtherabbit]

nono I'm not trying to put a long slide on my 4516-1 per se I'm trying to find a home for the 645 slide assy. And yes lol I know it's a 2nd gen.

I know about the barrel hood differences, but what threw me was the fact that there was a change to the barrel to frame lug amongst barrels with the same narrow hoods. I'm trying to determine when that dimension was changed to know which (if any) third gen frames will mate with the 645 barrel. I assume 4506 no dash is g2g because it's pretty much just a 645 with one piece grips but I was hoping for other options.