Someone had to get the ball rolling.:ph34r:
Thats interesting about the MK18, is there any public files to view about this?
Main reason i looked up this thread was because of the 2003ppt. About the CQB-R had these in it.
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Someone had to get the ball rolling.:ph34r:
Thats interesting about the MK18, is there any public files to view about this?
Main reason i looked up this thread was because of the 2003ppt. About the CQB-R had these in it.
So a month or so ago one of the rings in my Larue BCG broke so I replaced them with the MacFarland.
It was uber tight to begin with and I expected that. But now after less than 500 rounds the rings will no longer support the weight of the carrier and the bolt nearly falls out under its own weight.
Gun functions just fine though so I am inclined to leave it alone.
Here are a few previous discussions on the subject:
https://www.m4carbine.net/showthread...ight=McFarland
https://www.m4carbine.net/showthread...ight=McFarland
https://www.m4carbine.net/showthread...ight=McFarland
https://www.m4carbine.net/showthread...ight=McFarland
https://www.m4carbine.net/showthread...ight=McFarland
See last question of the Armalite FAQ regarding the McFarland ring:
http://www.ar15.com/forums/t_2_27/16...ome_FAQ_s.html
and
http://www.armalite.com/ItemForm.asp...e-c76eaa613b0a
http://www.armalite.com/ItemForm.asp...e-c76eaa613b0a
"– CQB Receiver –
M4A1 Carbine with
10-Inch Upper Receiver"
"Presented by Jeff Johnson
Weapons Department
Ordnance Engineering Directorate
Naval Surface Warfare Center – Crane, Indiana"
The PDF is public domain, released by NAVSEA/Crane.
www.dtic.mil/ndia/2003smallarms/john.ppt
Slides 8 & 9
Also here:
https://www.m4carbine.net/showpost.p...2&postcount=44
I've had a little experience with these rings. What I've found is they can be completely different diameters, from the same source.
I know that Armalite sends these out with every AR10 BCG that goes out their door. However, the 308 action is very different - you really almost CAN run an AR10 BCG without gas rings. My AR10 BCG is as loose as it was day one and it's been 100% reliable.
Back to the 5.56 versions, I've even swapped around these gas rings on various BCGs to verify it wasn't the BCG that was different dimensions. I own 5 of them (experiement) - each seems to have it's various dimensions. Some are so tight I have to force the bolt into the carrier, some are so loose it drops right in. I've never taken the time/ammo to do any real testing with them and have pretty much resorted to regular rings on a maintenance schedule.
I still have all of the rings. It's good to hear many are very pleased. Have you all seen this much variance in manufacture between the different rings? I wish somebody would say, it doesn't matter. I know Armalite gives an acceptable variance measurment on their website - 'cept I don't have a micrometer.
Had to order some stuff from DSG last week so I threw a couple McFarland rings on the order based on some of the recommendations in this thread. Both of them have an OD of 0.5025". I'll be PMing my Noveske upper in the near future and installing one.
mine will be here tomorrow to go on my Bolt with around 1,500 rounds on it so well see how it does
I'M going to be switching out standard gas rings shortly on by BushMaster and Colt and will also go with the McFarland rings this time a round.
Will report back later with results.