LE6960-CCU Colt Combat Unit Carbine
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BattleRife
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I'm going to guess that Colt will be outsourcing all components related to that mid-length barrel and gas system.
The clue: the barrel material is listed as 4150 CMV, while any barrel Colt makes for government contract must be chrome-moly-vanadium per MIL-B-11595. It would be a logistical accident waiting to happen to allow a non-conforming material into the Colt barrel works.
The clue: the barrel material is listed as 4150 CMV, while any barrel Colt makes for government contract must be chrome-moly-vanadium per MIL-B-11595. It would be a logistical accident waiting to happen to allow a non-conforming material into the Colt barrel works.
Exactly lol.
Cool offering.
Here is a little secret guys, Trump won the presidency and things are changing at COLT now soon.
MK18 will be made more available as Tax stamps will be by by. Donald Trump Jr knows all this stuff and Trump elect already addressed this.
M4A1 marked lowers coming along with all other stuff at Colt USA.
Good times coming from Colt. BY 2018 unless Trump gets assassinated.
This is from a very reliable source.
BattleRife
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Yep I have, got a copy right here:
CMV indicates chromium, molybdenum and vanadium, but that doesn't make 4150 CMV the same as chrome-moly-vanadium as listed in MIL-B-11595. 4150 CMV itself is a non-standard steel not defined by any widespread spec I have ever heard of, but the base chemistry of 4150 is well known and listed separately within MIL-B-11595, look at the table and you will see that in addition to some non-overlap in carbon and manganese, the specified ranges for molybdenum are mutually exclusive. If it is a 4150 it cannot be chrome-moly-vanadiam per MIL-B11595. And yes, Colt does have to use the latter.
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BattleRife
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The only important takeaway from that post is that barrels from Colt and FNMI were tested and found to comply with the chemistry of chrome-moly-vanadium per MIL-B-11595, and not with any breed of 4150.
The rest is what happens when a guy who works in firearms retail tries to interpret the world of metallurgy and engineering specifications.
I stand by my first statement. Colt has probably outsourced manufacture of mid-length components because it would be unwise to allow non-conforming 4150V material into their manufacturing facilities.
OK, so technically I misspoke. 4150 technically can't be CMV because of the lower carbon content. 41V45 would be more correct I guess. Basically 4150 CMV is more marketing than anything else.
Take a look at Colts spec sheets though and every single AR is listed as 4150 CMV, which as you've pointed out isn't technically correct.
And no they don't have to use CMV. As long as they use any of the three specs listed they'd be GTG.
ETA: I'm no metallurgist, nor do I play one on TV.
Take a look at Colts spec sheets though and every single AR is listed as 4150 CMV, which as you've pointed out isn't technically correct.
And no they don't have to use CMV. As long as they use any of the three specs listed they'd be GTG.
ETA: I'm no metallurgist, nor do I play one on TV.
BattleRife
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I'm just drifting back to this thread now.
4150 can't be chrome-moly-vanadium per MIL-B-11595 (CMV) because of the molybdenum content. The carbon content of CMV, 4150 and even 4145 show considerable overlap, and it is entirely possible to produce a steel that meets all 3 specs at the same time. But the minimum moly content of CMV is significantly higher than the maximum moly content of the AISI steels.
Interesting, I didn't check that. Sounds like the marketing folks got into the brochures and tinkered with the facts in order to convince people they are getting what they think they want, rather than what they actually want (but don't know they want). The AR-15 barrel steel question has been so confused for so long that unfortunately this is not uncommon.
Everything I have seen says this is untrue. The 3 steels listed in the spec are absolutely not equivalent or interchangeable. They have distinct properties and are intended for specific applications. My references say Stoner specified the CMV steel after AR10 prototype #1004 exploded in testing at Aberdeen, and that has been the material of choice ever since. I have a copy of only one Colt barrel drawing, an M16A1 barrel probably dating to the 1970s, but it does not say "use whatever MIL-B-11595 steel you can find", it says "chrome-moly-vanadium per MIL-B-11595". Use of either ORD 4150 or ORD 4150 Resulphurized in the face of this drawing callout would be a violation of their contracts with US government.
4150 can't be chrome-moly-vanadium per MIL-B-11595 (CMV) because of the molybdenum content. The carbon content of CMV, 4150 and even 4145 show considerable overlap, and it is entirely possible to produce a steel that meets all 3 specs at the same time. But the minimum moly content of CMV is significantly higher than the maximum moly content of the AISI steels.
Interesting, I didn't check that. Sounds like the marketing folks got into the brochures and tinkered with the facts in order to convince people they are getting what they think they want, rather than what they actually want (but don't know they want). The AR-15 barrel steel question has been so confused for so long that unfortunately this is not uncommon.
Everything I have seen says this is untrue. The 3 steels listed in the spec are absolutely not equivalent or interchangeable. They have distinct properties and are intended for specific applications. My references say Stoner specified the CMV steel after AR10 prototype #1004 exploded in testing at Aberdeen, and that has been the material of choice ever since. I have a copy of only one Colt barrel drawing, an M16A1 barrel probably dating to the 1970s, but it does not say "use whatever MIL-B-11595 steel you can find", it says "chrome-moly-vanadium per MIL-B-11595". Use of either ORD 4150 or ORD 4150 Resulphurized in the face of this drawing callout would be a violation of their contracts with US government.
Interesting, I guess I'm misunderstanding the whole MIL B 11595 thing. I assumed that as long as it meets the spec it would be GTG. Otherwise why not list the specs seperately? A very good explanation though, thank you.
It doesn't help that 4150 CMV or even just plain 4150 has become a marketing term that just leads to more confusion.
It doesn't help that 4150 CMV or even just plain 4150 has become a marketing term that just leads to more confusion.
