Re: COLT 22lr Conversion Unit, c.1972.
Awesome, guys.
I appreciate the experienced information and the ideas I hadn't considered, but one reason I hadn't is because I'm not sure we are discussing the same kit. Is any Colt Conversion kit with a floating chamber considered an "Ace" kit? This unit is with box and papers, none of which mention "ACE". So, is there an Ace, and then another kit by Colt? And then the Ace kit would be more valuable than the non-Ace unit? Or whether the unit says ACE or not, the collector value is the same.
Not being a Colt expert......teach me.
Found this:
There always seems to be some confusion about what is an ACE and what is just a Colt .22 conversion unit; some of which are not marked as an "ACE" since that is a specific model of pistol. The first commercial ACE pistols were produced from 1931-1941 and then again in 1947. The Service Model ACE pistol was produced from 1935 to 1945 and had a floating chamber. They used a similar but different magazine that is now used in the latter .22 conversions and Marvels.
You should check a current copy of the Blue Book of Gun Values and see what .22 converison or ACE unit you actually have. The CMP sold a bunch of .22 conversion units about two years ago. I picked up a pretty much NIB box one from them for $300. Prices for an ACE conversion, especially the one that was used to change a .22 Service ACE pistol to .45 ACP can go for over $3500. The ACE conversion to change a .45 to .22 will go for considerably less.
Some conversion have fixed sights; some have adjustable. There is also an ACE II conversion which is for Series 80 1911s.
AND this:
There were actually two guns and two conversion units.
The original Colt ACE was .22 LR only. It had no frame mounted ejector and the slide was narrower and lower than the .45 slide as well as being heavily cut out inside to reduce weight. It was pure blowback, with no floating chamber. It was not too reliable (though my two function well) and the very light recoil was not considered good for training those who would use the .45 on duty.
So Colt came out with the .22 LR caliber Service Model (SM) ACE. Its slide is the same as the .45 slide. In order to work with the heavier slide, it uses a floating chamber that causes more recoil and makes it "kick" more like the .45.
Then, to convert .45 pistols to .22, Colt made conversion kits using the SM ACE slide and floating chamber. (There were no conversion units for the original ACE.) There were several versions of the conversion unit, with mostly cosmetic changes. There was another conversion unit for those who had bought the SM ACE; that unit converted the SM ACE pistol to a .45.
And, last, this. Kinda says it all.
I have a Colt 1950s (maybe 60s as it is not serialized so no way to tell) .22 LR adapter atop a Norinco frame. I have literally shot 500 rounds a weekend through it every weekend for 5 years. I only clean it when my concience bothers me. The between-cleaning intervals would be described as every 20 bricks.
I use Federal (Walmart Federal Value Pak 550 rounds/brick) copper plated .22 LR HV. This would be described as the cheap stuff. I have never used lead. Federal powder is so clean burning that there is no apparent reason to clean the gun. Use of Remington ammo is not recommended. It is the closest thing to black powder in gumming up a gun that I have seen. For sure it will glue the chamber to the barrel in a few rounds.
To those of you that have problems with the floating chamber, I read similar complaints on forums before and used to clean the chamber after every usage (several hundred rounds) for no other reason than I believed I had to based on the comments on forums. I didn't have time after one range day to clean the gun, so I took it "dirty" to the range the next day to see how long it would go without cleaning. Never did find out. It just kept on ticking.
One thing that I did a while back was to use a Dremal tool with small hard buffing tips and automobile polishing compound (because it was what I had on hand) followed by metal polish to put a mirror finish on the inside walls of the barrel and outside surfaces of the floating chamber. Those surfaces gets sooty after a few thousand rounds and I re-polish when I am cleaning the gun. Again, that isn't very often. Not much sticks to a highly polished surface.
I have fired this gun so much that the barrel broke. The square shaped hook at the back of the barrel that retains the floating chamber, broke off. The gunsmith did a bit of magic and silver soldered a new fabricated piece and I am back in business. Replacement barrels are non-existant.
Replacement magazines are however, available at Brownells. Two brands. Meggar and Triple K. I have had good luck with Triple K. I tried both. Tech support at Brownells told me that the success of one brand over another is more dependant on the particular gun. They get just as many returns in exchange for the other brand for each brand. The usual problem with aftermarket mags is with the little piece of the follower that extends out from the body of the mag that pushes up on the slide stop to lock the slide back. The factories use blind or near blind assemblers. They grind the plastic protrusion to the "right" shape. Unfortunately, no one told them what the right shape is. If you use a small fine file, similar to the old point files we used on the breaker points in the distributors of the pre-electronic ignition cars, you can form the protrusion so that it stops dragging on the inside wall of the mag and still protudes out far enough to contact the slide stop. The lock-back will work once you get the right shape.
I "accurized" mine with a Briley bushing (Brownells). Matching the bushing size to your gun is simple. You will need an accurate measuring device. If you reload, you already have what you need. Note that the barrel is not a constant diameter-- the last 1/2" at the muzzle is larger than the rest of the barrel. Keep that area greased for the first 2000 rounds-- I keep it greased all the time. The fit with the correct busing is .0005. Oil will squeeze too easily. My groups are less than 3" consistantly at 25 yds (from a rest).
Other notes:
Extractors are very delicate. They break. Buy two or three if you can find them. Gun Parts now says it has Colt originals. Ejectors are hard to find. Buy an extra.
Wolff Springs makes replacement recoil springs. They also make what they call universal .22 magazine springs. Buy a 10 pack. Replace the one you have as soon as you get them. A new mag spring will make most of the "failure to ...." problems go away. The Wolff spring is significantly stronger than what is in your mag now. Do not cut or trim the mag spring-- use it full length.
I never clean the bore of my gun. No need with Federal.
I use grease, not oil on the rails-- any grease will do, but I use white litium that we used to use on auto brakes. Available at hardware stores, not auto supply anymore. Use sparingly so no grease gets in the chamber area. Use no oil on the gun except on the sear (slide closed, cock hammer, two drops into the hammer. With no lube in or around the chamber area, and no lube at all on the floating chamber/barrel contact area, the gun will shoot until you want to clean it, not some "every hundred shot" requirement. That's totally not required.
This adapter is reliable and accurate if you keep the lube to absolute minumum and install a Briley bushing. I installed a Briley on my Mdl 70 and it cut the group size to 3" at 25 yds. Worked so well, I thought I'd try one on the adapter. Worked just as well.
I shoot my guns one handed to 50 yds. I shoot 2-3 mag of .45 in my MDL 70 until the tremors set in, then I shift to the Norinco with the adapter installed and shoot until the tremors go away, then return to my MDL 70. The hard part in all this is holding that heavy gun way out there.
