[Jim Watson]

1. Ace (Blue Book calls it "Commercial Ace", some people call it "Target Ace.)
One-piece barrel, slide extensively lightened and shortened (4 3/4" barrel) to function with .22lr. Made 1931-1941. BB says some in 1947. Never offered as conversion, just complete guns. Wish I had bought the one offered a number of years ago.

2. Service Model Ace.
Floating chamber to cycle standard size slide and give some recoil sensation. Made 1935-1945 with some parkerized military models. Reintroduced 1978-1982. Available as complete gun or conversion for use on G.M. Several variations, old adjustable sights, new adjustable sights, fixed sights, etc. There is also such a thing as a .45 conversion to make a SM Ace into a centerfire. Only 112 manufactured, ca 1940. I have a .45 upper for my Ace made up out of spare parts for testing different sights without messing with 1911s that are like I want them.

3. Ace II. Conversion only. Aluminum slide, bilboard markings. I saw them advertised by C-More Sights but know little about them. I don't know if they are a real Colt product or made by a licensee or knockoff.

I don't know their reasoning for sure, I suspect the original Ace would have been picky on ammo and the Service Model would give more certain function. The Ace II aluminum job for cost cutting, much simpler design than Ace or SM Ace.

 

[RickB]

Ace, Service Model Ace, .22-.45 Conversion Unit, and Ace II are all different animals.
The Ace and Service Model Ace are complete guns. The other two are conversions.

 

[Mac Attack]

Thank you for your replies.

Does anyone know where a person could find a spare complete barrel and floating chamber? I would like to keep one as a spare and can't seem to find one. I'm really surprised that no one has offerred a custom barrel for it yet?

Also, does the single barrel offer any accuracy improvements over the two piece set up?

 

[Jim Watson]

I don't know of a source for barrel/chamber, Numrich is sold out.

I don't know anybody who has shot a "Target Ace" to say how much more accurate the fixed barrel is. My gunsmith has ideas about locking down the chamber and reducing slide mass and recoil spring to let the gun run in straight blowback as part of accurizing but I won't let him rebuild my gun to find out if it matters.

 

[RickB]

Colt barrels show up on ebay, occasionally. I've been able to get a spare chamber, extractor, and firing pin, via ebay.
The Ace and Conversion Unit will respond to the same accurizing mods as the centerfire guns. At the rear, the slide stop pin fit needs to be improved in both the frame and the barrel lug, and at the front, a match bushing.
I've miked about ten "1911s" of various makes and models, and the slide stop pin holes vary from .201"-.204". If the slide stop pin is .198"-.200", you'll have some movement. I suspect the hole in the barrel lug is about the same range as the frame, so you could remove the play at the rear with an oversize slide stop, and an appropriate reamer for the frame and barrel. Of course, the .22s have their own slide stop, so I doubt you could find a slide stop that is both compatible with the chambering, and oversize. Maybe a 9mm/Super slide stop could be welded up or otherwise adapted. A standard match bushing can be fitted to the muzzle and slide.
Supposedly, the reason the original Ace didn't work so well was due to inconsistent ammunition. The unreliability of autoloaders, assumed since the early days of auto pistol development, was apparently due as much to variability of ammo, as any problems associated with gun design. If you had a weak round or a dud in a revolver, you just pulled the trigger again, but a dud or squib in an auto meant that you had to cycle the gun to get it back in action. The .22 ammo of the '30s couldn't consistently cycle the Ace, and that's one of the reasons the Service Ace was developed. With today's ammo, the fixed chamber appears to work fine in the Ciener and other conversions.