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 Opinions on open bolt conversion uppers...
1928A1  [Team Member]
11/21/2006 2:15:26 PM
I have seen these uppers for around $1500 called the LMG upper. Are these any good? What do they bring to the arena? Can you run Beta after beta through them?

Thanks
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Zack3g  [Team Member]
11/22/2006 7:02:39 AM
From what I've read, the original Colt LMG open bolt conversions were designed for "sustained" full auto fire. The problem arises with not being able to find out exactly what they mean by "sustained"..





(stealth tag for more info)
Hail Mary  [Member]
11/22/2006 6:04:25 PM
Had a few over the years and they can take 3 Betas back to back easy; done that. I ran them using standard closed bolt parts as I didn't want to mess up my lower going open bolt. The gas tube is extra thick (as least the real ones) BUT the big problem is no one has spares. If you manage to melt that gas tube, you'll have to machine your own. What I find they can really do nicely is accurate suppressed fire. Had one that was really accurate with my special load. But I ended up dumping them all because of the lack of parts issue and the availability of cheaper bull barrel uppers.
1928A1  [Team Member]
11/22/2006 9:31:25 PM

Originally Posted By Hail Mary:
Had a few over the years and they can take 3 Betas back to back easy; done that. I ran them using standard closed bolt parts as I didn't want to mess up my lower going open bolt. The gas tube is extra thick (as least the real ones) BUT the big problem is no one has spares. If you manage to melt that gas tube, you'll have to machine your own. What I find they can really do nicely is accurate suppressed fire. Had one that was really accurate with my special load. But I ended up dumping them all because of the lack of parts issue and the availability of cheaper bull barrel uppers.


How do your bull barrel uppers compare? How many rounds can you do and do you melt gas tubes with it? What damage does the LMG upper cause?

Thanks
slt223  [Member]
11/22/2006 10:13:37 PM
It is my understanding the OB parts egg out the hammer hole. The gas tube is is about 1/4" in diamter, maybe a little fatter. You cannot get replacement parts for it because they need be F6'ed in from Canada as they are made by Diemco I beleive. The F6's, so I"m told do not get approved. Someone will speak up if I'm off base somewhere.

Edited to mention the model # is RO750 if you want to research it more.
Hail Mary  [Member]
11/24/2006 12:40:34 PM
No one has spares for the LMG uppers, not even Diemanco in Canada. The standard bull barrels weak link is the gas tube, they will melt after 1+ Beta dumps.
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