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Posted: 11/28/2005 10:32:51 AM EDT
| How hard is it to change a barrel extention on a barrel or can it even be done by the home AR15 mechanic? Are there headspace issues involved? Thanks. |
It is NOT an easy project for an amateur. Charles the Gunsmith. 
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This IS where the headspacing is set on an AR15/M16; at the mating of the barrel extension to the barrel. This is not for graduates of Wiley Coyote School of Gunsmithing. Suggest you buy a complete new barrel assembly and leave the professional work to the pros. Mike |
| Thanks, I was afraid that might be the case. I just noticed they were selling barrel extentions (although they are out of stock) with M4 feed ramps over on Bravocompanyusa.com, and I wondered if I could install one on a barrel that does't have feed ramps so it would match up with an upper that does. But I guess it's probably a better idea just to get another upper. I'm just currious though, what keeps the barrel extention from turning once it's installed, does it tighten down solidly against part of the barrel or is it the barrel indexing pin? Thanks. |
Barrel extension is torqued against the barrel shoulder (for the extension) at around 150 ft lbs. |
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My response was a simple dollars and cents answer. The extension costs $21.95 and the tool costs about $60. The cost of labor to get it done is another story. I simply wouldn't do it because I'm lazy. M4 ramps and bayonet lugs.............................................the money spent on these two useless options makes me wish I were tooled up for this kind of work. IMO, IIRC, YMMV, et al. |
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Unscrewing your present extension and screwing a new on on is easy. Getting it to index properly and headspace all at the same time, that is the problem. The barrel extension is really put on during manufacture, and all the rest of the barrel is finished around it. That is, it is put on the barrel, the chamber finish reamed, index pin, barrel port, front sight base, etc, all done to line up correctly. From what you would spend on the extension and tool, you are almost to a new receiver. You could also have someone ramp your extension. Or trade your upper receiver for one without the ramps. The last thing you want to do is screw up a perfectly good barrel by trying to change the extension. The cost to pay a machinist do all that is required is just prohibitive. This was not a part that was intended to ever be replaced. |
"MyRight" It's a 16" M4 bushy barrel. I appreciate the offer, but I have already ordered a (non-m4 cut) reciever to match it. I think I have decided to just hang onto it and save the rest of my parts for a CMMG barrel I have been thinking about buying in the future. I never was really that worried about having M4 ramps, since I've never had any problems from an upper that didn't have them. I just figured if it was an easy switch, it could save me from buying another reciever. I figured it wasn't that easy though. It sounds like changing the barrel extention on a finished barrel is pretty much next to impossible. Thanks everyone, for all the responses. |
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