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Posted: 2/7/2017 11:10:11 PM EDT
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Hi,
I have Black Rifle II, and it shows the bolt reliability kit in the M4A1 SOPMOD section. I wanted to see if anyone had the specifics on the parts list? I have a good deal of information and also understand several companies make similar kits but I'm interested in the NSN kit that the military currenty uses for SOPMOD Bolt Upgrade: Viton Crane O ring Milspec Extractor Spring Insert Extra Power Extractor Spring - not in original kit/not sure if it's officially used? Extra Power Ejector Spring One Piece Gas Ring This is what I have can anyone ellaborate on additional items and specific brand names or manufacturers? Thanks! |
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Quoted:
That was a good upgrade 10 years ago, but wasn't 100% GTG in every gun. I saw plenty of problems with the o ring and those junky McFarland gas rings. Today, the better option is a Colt extractor with copper spring and black insert and a new set of Colt rings. This is the truth right here. Last time I ordered from Brownells, I just ordered a bunch of those along with my order so I have spares, or can help someone having malfunctions related to those parts. Colt gold springs are like $5. |
| I have been using Colt bolts and gas rings and Sprinco extractor five coil springs with insert and viton oring. I'm ordering some Sprinco ejector springs for all my bolts soon. So standard gas rings, and the enhanced spring with insert is good to go? I heard the McFarland one piece rings issues were due to the fact that folks would believe they were unservicable because they would not provide as much resistance when they did the BCG Inversion test? Can anyone ellaborate? They currently cost less than Colt gas rings. I found several different American made manufacturers selling them for $2-2.99 each. |
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I use BCM extractor springs, but I think the point is to use HD springs vs. standard springs.
I do not need and do not use the o-rings in any of my AR’s. I have never had a problem with McFarland rings and I have several sets in use some dating back to when they first came out. |
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Quoted:
I use BCM extractor springs, but I think the point is to use HD springs vs. standard springs. I do not need and do not use the o-rings in any of my AR’s. I have never had a problem with McFarland rings and I have several sets in use some dating back to when they first came out. The Navy found that the McFarland rings increased mean rounds between stoppages significantly. It reduces friction and apparently when they shine is with heavy carbon buildup. I don't know if I'm convinced they are better than standard gas rings.. I believe one major improvement is the enhanved extractor spring and a heavier CrSi buffer spring. Analysis of the military is that the springs don't get changed often enough. If they did it's likely there would be fewer stoppages. |
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I have been using Tubb’s flatwire CS action springs since they came out generally with heavier buffers.
The Tubb’s spring works with both rifle and carbine stock setups. As long as you don’t let them rust CS springs should be good for the life of the weapon. There have been posts about problems with Tubb’s springs and McFarland rings, but that is not my experience so I will continue to use them. |
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Quoted:
It was a stop gap upgrade until the Army finished testing the Colt upgrades. I believe the Colt copper extractor spring + black insert, new gas rings, and ejector spring all finished testing in 2007. |
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