thoughts on 22lr conversions

[Les Snyder]

I installed a CMMG drop in conversion unit on my backup 16inch Colt flat top before last year's Ft. Benning match. I wanted to work on some transition positions (Kyle's Highsmith Drill)and noticed a couple of problems after 500 rounds or so... first the unit worked well, with so so accuracy but the rimfire rounds leaded the Miculek comp badly, and filled the action with carbon and lead deposits. I was leary of what was deposited in the gas tube, so removed the conversion unit. Being relatively cheap by nature I really didn't want to shoot center fire if I can shoot rim fire for muscle memory practice. Then it dawned on me, you don't need a gas tube with a blow back conversion unit, so I removed the gas block and tube, covered the gas port with a stainless fuel line screw clamp, and removed the comp and replaced it with a standard flash hider without wipers to act as a thread protector. Took the CMMG unit apart... gave the rails the high buff and posished the feed ramp. At my age I need all the practice I can get

regards

Les

[rr4406pak]

When you removed the gas tube what did it look like inside?

Was it all fouled up too?

[Graham Smith]

I have not put enough rounds through mine to see but on the advice of someone who has, I got a thread protector to replace the compensator when shooting .22LR Also, I have been told, that a few rounds of .223 every few hundred rounds of .22LR will clear the leading and the gas tube. But I'm going to file the idea about removing the gas tube for future reference.

[bushmeat]

Les, basically you now have a dedicated .22 upper.

I use my Ciener conversion in my competition gun. So I get the same trigger feel and sight picture for .22 practice as I would for .223, just not the muzzle flip. Stingers shoot to POA at 25 yards, so I don't even have to adjust my sights.

After removing the conversion unit, while shooting .223 through the bore will indeed clear out the gas tube, it will just deposit that gunk into the bolt carrier. I prefer to squirt Action Cleaner or Brite-Bore through the gas tube and just let it drip out. That helps clean the muzzle brake as well.

[Doug H.]

I picked up a CMMG unit at the FNH match last year and set up a dedicated upper with the cheapest upper receiver and tube handguard that I could find plus a used 16" barrel I had laying around. I have about $125 into it and it works like a champ. Eats CCI minimags without a hitch. I have about 2000 rounds thru it and finally cleaned it this past weekend because I'm lending it to Busyhawk to use at a class. The inside was covered in thick gray stuff so I hosed it off with brake cleaner and lubed it. Just don't use cheap ammo and they work fine.

Doug

[Les Snyder]

rr4406pak....I had fired about 200 rounds of 223 thru it after the .22lr before removing the tube... didn't see anything visually inside the tube, exterior of tube was caked, don't have any of the long pipe cleaner... really made a mess of the CMMG unit and interior of the receiver. I have Rock River triggers in all my AR rifles and not much noticable difference in pull. I have a 10-22 we built for the Chevy Truck Team Challenge years ago that will hold a 1inch group at 100y and still using up ammo from that time.

I have a friend that used to get the year old Sox and Martin Hemi cars... he had several but didn't keep any of them

Les