M1911 45ACP Slide on a 9mm Frame

[stansdds]

If you want to get real tricky. Mill the .45 slide out to accept a 9mm ejector, then you have the best of both worlds and all you have to do is swap out the slides when you want. The 9mm ejector will work on all calibers.

Bingo! 9mm, 38 Super, 40/10mm slides are milled for a wider ejector. To put a 45 ACP slide on a receiver that was originally made for one of the smaller diameter calibers, you either mill the 45 slide or change the ejector. As to receiver feed ramps, my experience was with a Colt Delta Elite, the receiver feed ramp is cut differently than any my 45 ACP M1911's. Barrels with integral feed ramps negate this potential issue.

 

[Rock185]

Over a good many years, I've experimented with so many combinations, I can't remember them all now. I do remember changing ejectors between .45 and 9mm, and recall that .45 slide/barrel worked on 9mm frames, but 9mm slide/barrel on .45 frames did not get along well. The .45 frame ramp being cut further forward caused feeding issues with the shorter 9mm cartridge. That little gap between frame feed ramp and bottom of barrel throat goes away when the 9mm barrel is used on the .45 frame, and 9mm barrel may actually hang out over the .45 frame ramp a few thousandths. Not my photo, but the attached picture does show the difference in the frame feed ramp machining between 9mm,top, and .45 ACP, bottom. Of course, using ramped barrels in each caliber, the feeding issues are cleared up..

 

[DWalt]

Over a good many years, I've experimented with so many combinations, I can't remember them all now. I do remember changing ejectors between .45 and 9mm, and recall that .45 slide/barrel worked on 9mm frames, but 9mm slide/barrel on .45 frames did not get along well. The .45 frame ramp being cut further forward caused feeding issues with the shorter 9mm cartridge. That little gap between frame feed ramp and bottom of barrel throat goes away when the 9mm barrel is used.

After many years of use, I have yet to experience my first feeding reliability problem when firing 9mm and .38 Super ammunition with any bullet using a .45 ACP frame. And that is using standard unsupported chamber barrels.

 

[Rock185]

DWalt, I am envious. Even the Colts I've had that were originally chambered in 9mm, to include my recently purchased 9mm Gold Cup NM, were reliable only with RN ball ammo. Same with the Colt 9MM conversion kit I had years ago. My last Colt SCG in Super 38 had trouble feeding ammo with wider hollow points. For example, the factory SIG V-Crown, or handloads with the Speer Gold Dot bullets could not be relied upon to feed reliably in my SCG Super 38. My 9s and Supers by other manufacturers, with the integrally ramped barrels, are reliable pistols with all types of bullet shapes, weights, pressure levels, etc.

I'd read such good reports by Colt 9mm owners in recent years about the reliability of their 9mm Colts, I bought the new GC in hopes it would exhibit the reported reliability. No such luck. Maybe next time...