AR Sponsor
Posted: 7/19/2011 6:17:37 AM EDT
|
New to me CMMG dedicated .22lr upper, received yesterday. Two years old, black anodized bolt, with set screw barrel collar. Two gray mags w/o fitting "bumps".
Seems to work OK with American Eagle LRN (so far just 10 rnds through each mag to check function). Jury is still out on whether or not it "runs". No BHOA, but bolt is held open after last round fired by magazine follower and remains open until mag is removed. This of course does not replicate full AR function, but it beats the heck out of a dry fire with a closed bolt on an empty chamber! The only thing that I have initally identified as an issue is the lack of "live round extraction. For me this is not just an annoyance, it is a potential saftey concern. My question is this: Can an older bolt be upgraded or modified to effect live round extraction? Thanks in advance for any advice. - G |
|
Quoted:
The only way to get the live round extraction is with a new collar, which will not work with the older barrel. What your other option is: Buy the barrel/collar combo and replace your current barrel and collar, still using your rail and bolt. Dave N Hmmm .... Somehow I thought that I could achieve effective Live round extraction by modifying or upgrading the bolt extractor claw. Worst case, I thought I might have to replace to entire bolt carrier assembly (realizing that I would probably have to retain the older barrel/collar) Replacing the barrel... and the collar... and the bolt shanks this one clean off the fairway. Not a $ option. Might as well buy a complete new upper. OK then... 1. Could the older set screw collar be filed or machined to allow for LRE (Live Round Extraction)? - If machining is possible and required, and I sent the collar/carrier to CMMG, would they be willing to do this? - At what cost, I wonder? 2. Could the new Evolution collar (with LRE functionality) be modifed to fit the older barrel extention., i.e. drilled and tapped for a set screw? - Would this also require a different extractor claw? 3. If it is possible, as you suggest, to remachine an older barrel to accept the Evolution (snap ring) collar, would CMMG be able/willing to provide this service? And again, at what cost? BHOA is a really great option, and necessary to those looking for full AR platform functionality, as such engineering time, talent, and resources have been allocated to develop this capability, and as I understand it, even to the point that it can be retro fitted to older dedicated uppers and conversions. Therefore, would it not also make sense to develop a retrofit collar for the older style barrels that includes LRE functionality? Somehow I got the impression that the only dif between the old collar and the new collar was the setcrew vs the snap ring and the "Go/No-Go" guage (and even that was unique to the SS collar only). Guess I didn't ask the right question. Which also begs another question: Short of buying a complete new barreled action to acquire LRE functionality, how DOES one safely remove a live round fro mthe chamber? :-( G |
| I have always removed the magazine, opened the action with my left hand, then tilted the barrel up to let the round slide out of the chamber. If the round is held in from residue because i have been shooting, I simply pull on the rim of the cartridge with my fingernail and it comes right out. |
|
Quoted:
Quoted:
The only way to get the live round extraction is with a new collar, which will not work with the older barrel. What your other option is: Buy the barrel/collar combo and replace your current barrel and collar, still using your rail and bolt. Dave N Hmmm .... Some how I thought that I could achieve effective Live round extraction by modifying or upgrading the bolt extractor claw. Worst case, I thought I might have to replace to entire bolt carrier assembly (realizing that I would have to retain the older barrel/collar). Short of buying a complete new barreled action to acquire this functionality, how DOES one safely remove a live round fro mthe chamber? :-( G Depending on how skilled you are with a Dremel or file(do this at your own risk) the live round extraction is achieved from the extractor cut in the collar. The new collars have a deeper cut. That gives the extractor the avility to get behind the round for live round extracton. You may even be able to cut a groove in the barrel for a new collar. Again, it depends on your skills. Dave N |
|
Quoted:
Depending on how skilled you are with a Dremel or file(do this at your own risk) the live round extraction is achieved from the extractor cut in the collar. The new collars have a deeper cut. That gives the extractor the avility to get behind the round for live round extracton. You may even be able to cut a groove in the barrel for a new collar. Again, it depends on your skills. Dave N A cub bear wearing boxing gloves is more adept than I! - G |
|
Quoted:
Quoted:
The only way to get the live round extraction is with a new collar, which will not work with the older barrel. What your other option is: Buy the barrel/collar combo and replace your current barrel and collar, still using your rail and bolt.Dave N Hmmm .... Somehow I thought that I could achieve effective Live round extraction by modifying or upgrading the bolt extractor claw. Worst case, I thought I might have to replace to entire bolt carrier assembly (realizing that I would probably have to retain the older barrel/collar) Replacing the barrel... and the collar... and the bolt shanks this one clean off the fairway. Not a $ option. Might as well buy a complete new upper. OK then... 1. Could the older set screw collar be filed or machined to allow for LRE (Live Round Extraction)? - If machining is possible and required, and I sent the collar/carrier to CMMG, would they be willing to do this? i doubt they would do this. not cost effective - At what cost, I wonder? 2. Could the new Evolution collar (with LRE functionality) be modifed to fit the older barrel extention., i.e. drilled and tapped for a set screw? I suppose it's possible but again, is it cost effective? - Would this also require a different extractor claw? Possibly. 3. If it is possible, as you suggest, to remachine an older barrel to accept the Evolution (snap ring) collar, would CMMG be able/willing to provide this service? And again, at what cost? Again, I would say no BHOA is a really great option, and necessary to those looking for full AR platform functionality, as such engineering time, talent, and resources have been allocated to develop this capability, and as I understand it, even to the point that it can be retro fitted to older dedicated uppers and conversions. Therefore, would it not also make sense to develop a retrofit collar for the older style barrels that includes LRE functionality? The improvements made to the new collar and barrel set up were put in place to alleviate problems with the older kits, which included the set screw. Somehow I got the impression that the only dif between the old collar and the new collar was the setcrew vs the snap ring and the "Go/No-Go" guage (and even that was unique to the SS collar only). Guess I didn't ask the right question. Which also begs another question: Short of buying a complete new barreled action to acquire LRE functionality, how DOES one safely remove a live round fro mthe chamber? :-( G |
AR Sponsor