I was wondering if the 9mm bolts in the Oly and Colt systems are the same. I've built my lower with the DPMS bobbed type hammer which i've read is compatible with the Oly style 9mm or .223 uppers. I was wondering if it would be compatible with Colt style 9mm or .223 uppers. Also the only 9mm bolt assembly i've got a chance to look at in person is a RRA Colt style which is solid on the buffer end. Do they make different styles of 9mm bolts?

Thanks,
David

There is a bunch of information on bolts and hammers HERE.

Quoted: I was wondering if the 9mm bolts in the Oly and Colt systems are the same. No, they is different.   The COLT 9mm  is the same length as a std 556 carrier, flat at front, and has a .125" pocket in the face for the case head to sit. The Oly is basically a 556carrier (lacking a few minor detail), with a bolt head protruding from the front of the carrier body. I've built my lower with the DPMS bobbed type hammer which i've read is compatible with the Oly style 9mm or .223 uppers. I was wondering if it would be compatible with Colt style 9mm or .223 uppers. If your hammer looks like mine, run whatever you want on top - Also the only 9mm bolt assembly i've got a chance to look at in person is a RRA Colt style which is solid on the buffer end. That "solid" is a weight slid into the bore of the bolt body... Do they make different styles of 9mm bolts? Yes,  COLT/RRA/ASA/Garrison,  and Olympic,  I have a Garrison. Thanks, David

Thanks again SBR7_11. I have a hammer like you've got pictured and i've been talking with TOMMY15 getting all the details on how he used the 4" M1S buffer tube on his 9mm...It looks a lot neater than the CAR or standard tubes sticking out. He said he removed the bumper and weights from a standard buffer. Cut it down to 1" , redrilled the bumper pin hole, reinstalled and pinned the bumper. Starting cutting down the buffer spring and manually cycled until it felt right, which ended up to be about 6" long for him, and removed the weight from the bolt. But he's using a 6" barrel with an Oly setup. I'd like to get the same results with a RRA upper though. Is there anyone that i could send everything to and let them get it to work together or am i jus p*ssing in the wind. My brains hurting.

David