Apparently CMMG changed their dimension to .700 and per Lothar-Walther I need a .675 to use their barrel. Thanks for any info or leads on getting one this size.
Does anybody know where to find a .675 collar for dedicated .22 AR upper?
- Thread starter Mike_in_FL
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Just have it machined down or sand it if super patient.
CMMG Collar length Question for Dedicated Upper - AR15.COM
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To be perfectly honest I haven't put one of these together before but I thought what they're referring to would be the O.D. of the barrel shank where the chamber is. And that the collar I.D. had to be .675 and at .700 it would have too much slop. Don't know. Owned an old DPMS dedicated complete upper but it was inaccurate and traded it off quickly.
It's the length not the inside or outside diameter. It will create a gap between the breech face and the bolt if you use the longer collar.
Yes. This issue was exposed a while back when a few of us at RFC ordered 17HM2 barrels. At least that's when we discovered it anyway. I think Lothar Walther had pre-made a bunch of 22LR barrels with that dimension and put a disclaimer on their website that you needed the "older" collar. Some guys have had luck sanding down the backside to achieve the shorter dimension. Some sandpaper on a flat surface, patience and set of caliper and you'll be there in no time.
Otherwise you might call CMMG customer service and see if they'll supply one for you.
FWIW I had a LW barrel in 22LR and it shot great! I sold it to a fella here at the hide. I hope he's enjoying it.
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Just have it machined down or sand it if super patient.
CMMG Collar length Question for Dedicated Upper - AR15.COM
Firearm Discussion and Resources from AR-15, AK-47, Handguns and more! Buy, Sell, and Trade your Firearms and Gear.
I went the sanding route on a flat glass plate and took my time and my LW barrel runs fine.
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