Picked up a Colt conversion unit with adjustable sights . I understand that the later post war units did not come with a barrel bushing. I am using it with a Series 70 45 with a collet bushing . Will this work ok or is there a designated 22 barrel bushing . I have not seen any
Colt Conversion unit question
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As I remember, the conversion unit was not supplied with a bushing. You would use the .45 ACP bushing.
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The standard Government Model barrel bushing was used.
The collet bushing will provide too much grip to the barrel, because the barrel is straight and not belled, and the whole affair has to be a bit loose for it to function well.
These Conversion Units are a lot of fun, so long as you use 'good' ammunition, and everything's clean and well-lubed.
I use Remington's 'Golden Bullets', because the gilding seems to be harder than others, thus a bit less prone to shaving - and I use Pro Shot's 'Pro Gold' to lube the floating chamber.
The collet bushing will provide too much grip to the barrel, because the barrel is straight and not belled, and the whole affair has to be a bit loose for it to function well.
These Conversion Units are a lot of fun, so long as you use 'good' ammunition, and everything's clean and well-lubed.
I use Remington's 'Golden Bullets', because the gilding seems to be harder than others, thus a bit less prone to shaving - and I use Pro Shot's 'Pro Gold' to lube the floating chamber.
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Some Conversion Units did come with the barrel bushing. The ones made during the 70s when Colt was using the MK IV Barrel and collet bushing a barrel bushing was included.
All you need is a standard barrel bushing and use the recoil spring guide and plug from the parent pistol. The Unit should have the correct recoil spring.
All you need is a standard barrel bushing and use the recoil spring guide and plug from the parent pistol. The Unit should have the correct recoil spring.
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Yes my 1978 came with a bushing. It is above one of my Gold Cups. I would not use the collet barrel bushing on one.
Watch out for lead build-up when you do shoot it. The 'floating chamber' can get leaded up. I only expect maybe 50 rounds or so out of mine before I disassemble and clean. I understand that this has always been a bit of a complaint against the CU. They are a RIOT to shoot though! I also wouldn't expect high accuracy.
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JudgeColt had posted about putting a light coat of grease on the floating chamber and it does seem to help. Yes some of these Colt Conversions and SM ACE will lead up, but I think it has more to do with the ammo used. I have some .22s that actually lead up the bore on my Service Model Clone: an early post-War Unit on a Caspian frame. I shoot about 50 rounds out of it when I do shoot it, and clean it every couple of range uses.
My 1970s issue Service Model ACE could be shot until it would not work any more, but then cleaning it was a chore. Good high grade .22s seem to be the answer with these Units, but with the trickling supply of .22s we shoot what we can get and are hoarding the several hundred CCI Mini-Mags we got.
I did have a Colt Conversion Unit that would lead up in about 20 rounds. I do not think there was any leade cut into the rifling. It just would not work.
My 1970s issue Service Model ACE could be shot until it would not work any more, but then cleaning it was a chore. Good high grade .22s seem to be the answer with these Units, but with the trickling supply of .22s we shoot what we can get and are hoarding the several hundred CCI Mini-Mags we got.
I did have a Colt Conversion Unit that would lead up in about 20 rounds. I do not think there was any leade cut into the rifling. It just would not work.
I've really never tested how far mine would go before causing problems. A friend of mine had his floating chamber lock up pretty badly, but I think he really pounded it with hundreds of rounds in one outing. CCI Mini Mag Round Nose seem to work well. They seem to work well for just about anything.
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I built a gun under a Colt Conversion Unit back in the early 90's. I still own and shoot that gun today, infact.......it's a favorite for me, both at the range and in the field.
Re: the Bushing, DON'T use the Collet bushing. The step at the end of the CU barrel is too short, and you won't get the benefit of the collet on the barrel.
Buy a "Gunsmith Undersize/Oversize bushing", and fit it to the barrel, and then to the slide. It's easy to do with emery paper, and a wood dowel.
Re: Recoil Spring.....I did a lot of experimenting, and to get the best accuracy, I now use a std 16 lb 45ACP recoil spring in an attempt to slow the slide movement....yes, my slide locks back when it should.
My CU will pretty much "Hold the Black" at 50 feet, and does the same at 25 yards on a 50 yard slow fire pistol target.
Re: ammo.........I also think the copper clad ammo is a benefit.
Re: The 2 pc chamber.........the copper clad ammo extends the cleaning schedule, but I haven't decided if running it dry is better than a grease or a lubricant.....Maybe I haven't found the right lubricant?
CU pistols are a "Hoot to Shoot", and they can help to make you a better Bullseye shooter, if you work with them.
I've used mine in the woods for Squirrels, and don't feel I need more accuracy...........but it would always help.
Enjoy your New Toy.
Tom
Re: the Bushing, DON'T use the Collet bushing. The step at the end of the CU barrel is too short, and you won't get the benefit of the collet on the barrel.
Buy a "Gunsmith Undersize/Oversize bushing", and fit it to the barrel, and then to the slide. It's easy to do with emery paper, and a wood dowel.
Re: Recoil Spring.....I did a lot of experimenting, and to get the best accuracy, I now use a std 16 lb 45ACP recoil spring in an attempt to slow the slide movement....yes, my slide locks back when it should.
My CU will pretty much "Hold the Black" at 50 feet, and does the same at 25 yards on a 50 yard slow fire pistol target.
Re: ammo.........I also think the copper clad ammo is a benefit.
Re: The 2 pc chamber.........the copper clad ammo extends the cleaning schedule, but I haven't decided if running it dry is better than a grease or a lubricant.....Maybe I haven't found the right lubricant?
CU pistols are a "Hoot to Shoot", and they can help to make you a better Bullseye shooter, if you work with them.
I've used mine in the woods for Squirrels, and don't feel I need more accuracy...........but it would always help.
Enjoy your New Toy.
Tom
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lawman,The only ".22 CU" bushing I have is in use. I do however, have several GI bushings.If you like,I'll send you the tightest one and just swap you for the collet bushing. I know a lot of folks don't like them but, I do. I've never had a problem with them in normal service.The collet bushing is suseptable to failure by removing it from its proper barrel because the big end of the barrel stresses the spring collet fingers "stretching" them. So, you're probably not helping the collet on your barrel.PM me if I can help. Regards, Nick
thanks but I lie the collet on the 45 ,never had a problem, there are some used collets in good shape on GB and E Bay ,will probably pick up a spare. Thanks
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I have half a dozen .22 conversion units that fit on 1911s. What .22 they like is important. Sadly, now that you can not walk in and choose then it is a problem. I can tell you my ACE likes Ferderal ammo, but the 500 round brick was bought 10 years ago.
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