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Posted: 1/29/2003 7:38:13 PM EDT
| I have a preban 6450 lower. I am interested in putting an a3 upper on this lower. Is it possible to use an a3 upper from a 223 cal colt rifle and screw on a colt 9mm bbl. Then place 9mm colt bolt/etc in upper and assemble. Is there something special about buying a complete 9mm upper or will what i want to do work? |
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You'll have to either switch to a 9mm hammer, or modify your .223 hammer to 9mm spex. The 9mm hammer can be used with both calibers, but an unmodified .223 will hang up on the 9mm carrier. The 9mm barrel and bolt/carrier assembly will work fine in a .223 upper receiver. You will also need 9mm magazine well block(s) and, depending on the manufacture of the mag block, may also have to switch the mag catch if you want the bolt hold-open to function with 9mm Colt factory mags. The only other possible problem might be the buffer, but in most semi applications the standard .223 buffer will run fine in 9mm. |
| since this lower (6450) is a 9mm lower the magblock and mag-catch issues should not be a problem, correct? If i understand correctly, i'll need to screw in the 9mm bbl to the 223 upper. Replace hammer/bolt assembly (current hammer is notched instead of being round so i understand that hammer will not work.) Assemble upper on lower. Insert colt 9mm mag in lower. No worry about magwell mods. Go to range. Is this all correct? |
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Colt 9mm ARs came from the factory with the 9mm mag blocks pinned into the receiver well, the proper 9mm mag catch, and the 9mm semi hammer. If yours has not been altered to use a .223 upper, you should just be able to drop on the 9mm upper and go shootin'. But having the incorrect hammer in there makes me wonder what else may have been changed. Can't really say without seeing it..... |
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