ugaarguy
Member
- Joined
- Mar 19, 2006
- Messages
- 13,828
Last week CMMG charged my card for the dedicated .22 LR barrel & chamber adapter that was back ordered a few weeks ago. Rather than dealing with the barrel nut, delta ring assy, a FSB or other gas block, cap, and handguards; I simply decided to go with a free float tube with it's own bbl nut from CMMG. While I was at it, I ordered an anti-jam charging handle as well.
I already had a Ceiner Atchisson 22 LR conversion kit on hand, and read a reply from a CMMG rep on another forum (can't remember if it was TFL, Arfcom, or M4C) stating that CMMG's chamber adapters should interchange with Ceiner & other Ceiner based kits. I purchased a cheap take off upper from the local range for $30 right after I ordered the bbl & chamber adapter. A take off A2 type flash compensator & crush washer from my spare parts bin rounded out the build.
Yesterday the CMMG parts arrived. The dedicated .22 LR chamber adapter easily replaced the 5.56 chamber adapter on the the Ceiner kit. Stupid here forgot to order AR-15 vise blocks, so I hand fitted everything onto the upper, and headed to the range. The gents at the range got everything torqued down to spec. The pic rail on the upper was out of spec (not unexpected on a cheap take off upper, but this build is about saving money), so we used a bar & dual thumb screw (M4 carry handle style) riser to mount the Aimpoint Electronic Mark III - also out of my parts bin.
I lightly lubed the bolt assembly, and headed onto the range. The setup was 100% reliable with CCI Stinger, Aguila interceptor, and PMC Scoremaster. The kit ejected the Scoremaster with less velocity, as expected, but had no issues with feeding. All ammo grouped well, especially considering I was using a red dot, rather than a more precise fine crosshair scope. The Scoremaster easily put 10 shot groups into the sight in target diamond which was completely covered by the red dot.
I didn't know that the anti jam charging handle was made from plastic until it arrived, but it's a solid piece, and it's only for use in a .22 LR kit anyway. On the even better side of the equation, I didn't know CMMG was using their WASP nitriding on even their .22 LR barrels. A nitrided .22 LR bbl should be extremely difficult to wear out. Sloppy upper to lower fit didn't matter because the riser kept the optic securely on the upper, which is what matters. Magazines were both the 10 round Ceiner skinny mag, and a 25 round Black Dog Machine AR-15 style mag. Both mags functioned flawlessly. I used the lower off of my M&P-15 Sport for testing.
If you're looking to turn a Ceiner style conversion kit into a dedicated .22 LR upper I can now strongly recommend the CMMG dedicated .22 LR barrel & chamber adapter. If you want cheaper trigger time on your AR-15, and don't yet have a .22 LR conversion kit, I'd recommend skipping the conversion, and getting a dedicated upper. Based on how well their barrel & chamber adapter performed in a mix master setup, I'd look hard at the CMMG .22 LR uppers.
I already had a Ceiner Atchisson 22 LR conversion kit on hand, and read a reply from a CMMG rep on another forum (can't remember if it was TFL, Arfcom, or M4C) stating that CMMG's chamber adapters should interchange with Ceiner & other Ceiner based kits. I purchased a cheap take off upper from the local range for $30 right after I ordered the bbl & chamber adapter. A take off A2 type flash compensator & crush washer from my spare parts bin rounded out the build.
Yesterday the CMMG parts arrived. The dedicated .22 LR chamber adapter easily replaced the 5.56 chamber adapter on the the Ceiner kit. Stupid here forgot to order AR-15 vise blocks, so I hand fitted everything onto the upper, and headed to the range. The gents at the range got everything torqued down to spec. The pic rail on the upper was out of spec (not unexpected on a cheap take off upper, but this build is about saving money), so we used a bar & dual thumb screw (M4 carry handle style) riser to mount the Aimpoint Electronic Mark III - also out of my parts bin.
I lightly lubed the bolt assembly, and headed onto the range. The setup was 100% reliable with CCI Stinger, Aguila interceptor, and PMC Scoremaster. The kit ejected the Scoremaster with less velocity, as expected, but had no issues with feeding. All ammo grouped well, especially considering I was using a red dot, rather than a more precise fine crosshair scope. The Scoremaster easily put 10 shot groups into the sight in target diamond which was completely covered by the red dot.
I didn't know that the anti jam charging handle was made from plastic until it arrived, but it's a solid piece, and it's only for use in a .22 LR kit anyway. On the even better side of the equation, I didn't know CMMG was using their WASP nitriding on even their .22 LR barrels. A nitrided .22 LR bbl should be extremely difficult to wear out. Sloppy upper to lower fit didn't matter because the riser kept the optic securely on the upper, which is what matters. Magazines were both the 10 round Ceiner skinny mag, and a 25 round Black Dog Machine AR-15 style mag. Both mags functioned flawlessly. I used the lower off of my M&P-15 Sport for testing.
If you're looking to turn a Ceiner style conversion kit into a dedicated .22 LR upper I can now strongly recommend the CMMG dedicated .22 LR barrel & chamber adapter. If you want cheaper trigger time on your AR-15, and don't yet have a .22 LR conversion kit, I'd recommend skipping the conversion, and getting a dedicated upper. Based on how well their barrel & chamber adapter performed in a mix master setup, I'd look hard at the CMMG .22 LR uppers.
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