I’ve been reading up a lot and have found that it has been discovered that, apparently, CMMG does not use proper “milspec”/MIl-B grade steel.
I searched this forum, Arfcom, and google and could not find any conclusive evidence if this was true or not.
Does anyone have a link or info to irrefutable evidence to this? If they are not using what they have been advertising, then what exactly do they use?
I own a middie that was built from mostly CMMG parts (including the upper group), and, despite having no problems even when putting it through light abuse in the middle of the country, I’d like to know exactly what my AR is actually made of.
I could be wrong since my search-Fu is umm…weak…but this what they have posted on their website for uppers
CMMG M4 Profile Uppers have the following standard features.
Mil-spec certified 4150 chrome-moly vanadium steel M4 contour barrel
5.56x45 NATO chamber
1/7 twist
Hard chrome lined chamber and bore
M4 feed ramps
11 degree recessed target crown
F marked forged front sight base
Parkerized Barrel including under the front sight base
A2 Flash hider installed with Peel washer
Forged A3 upper receivers are T marked and have extended feed ramp cuts (M4 ramps).
Semi Auto bolt carrier
Each barrel is individually magnetic particle tested. Barrels are engraved CMMG MPC 5.56 NATO 1/7. Each Upper is head spaced and test fired before shipping. Upper specific features are listed with the individual item. When selecting the gas piston operating system, it will override your choices for the bolt carrier and front sight/gas block.
and the barrels
CMMG M4 barrels have the following standard features.
Mil-spec certified 4150 chrome-moly vanadium steel barrel
5.56x45 NATO chamber
1/7 twist
Hard chrome lined chamber and bore
M4 feed ramps/Barrel Extension
11 degree recessed target crown
1/2x28 Threaded Muzzle
Parkerized Barrel, including under the front sight base
F marked front sight base for flat top receivers
Round M4 Handguard cap
M4 contour for attaching 40mm M203 and 37mm Less Lethal launchers
Each barrel is individually magnetic particle tested.
Barrels are engraved CMMG MPC 5.56 NATO 1/7.
Barrel specific features are listed with the individual item.
All of their standard uppers have their barrel steel advertised as you listed, along with all the other features. No real difference until you look at their other sections that have nitriding, WASP coating, etc.
However, the M4 chart no longer credits CMMG as using a correct or better grade of steel. It used to a couple years back, but does not now.
I have one of their mid length uppers currently, I have only put around 450 rounds through it with no problems. If you aren’t having a problem with anything I wouldn’t worry too much about mil-spec. But then again thats my own opinion. I’m military and mil-spec usually means lowest bidder. For example I am avionics on the B1-B our FCGMS (Fuel Center of Gravity Management System) computer is made by BF Goodwrench. What the H*ll is a car parts manufacture doing making Fuel computers for a multi million dollar air craft?
I think the deal with CMMG is that no one really knows what the deal is with CMMG. Lots of reports of long wait times, bad customer service, etc. Some accusations that materials used are not what have been advertised. That said, I’ve used a few CMMG barrels in builds and have been happy with the quality. Not happy with the fact that they seem to no longer produce a chrome-lined 1:8 twist barrel. They were about the only outfit in town making a barrel of that type.
This has been discussed numerous times here before. Milspec does not mean lowest bidder. And every company that produces anything Milspec must meet the minimum requirements as set forth by the gov’t. So if a company can’t meet that standard what does that say? There are of course those that exceed the standard as well.
Why is a stretch for a car parts manufacturer to make something for an aircraft? There are plenty of companies out there that have diversified manufacturing capabilities. Think back to WWII when companies supported the war effort by manufacturing weapons and other equipment outside of their normal purview for the gov’t.
Here’s my take on the whole question - Don’t sweat it. It ain’t worth it.
I’m Dave and I’m an engineer. (Hi, Dave!) I think I remember this correctly. Generally, the M4, M16, etc. are spec’d to use 4150 ordnance steel. It’s a good choice to stand up to overheating and full-auto shooting. Many recreational barrels are made from 4140 steel because its a bit easier to machine. That means that machine tools last longer and barrels cost less. I don’t know what CMMG’s barrels are made from, and I’d be surprised if their supplier hadn’t had to change alloys from lot to lot if materials are in short supply.
Performance-wise, I don’t think you can create conditions where a barrel made from 4150 would function OK, but one made from 4140 would fail. I don’t think a recreational shooter will notice the difference. A scientific sampling of say 2 million barrels (GI quantities) might turn up statistically significant differences, though.
This is one situation where I think “The List” gets overly anal. Chrome-plated chrome-moly steel gets a check mark, but something like stainless would be “incorrect”? Get outa here. Just don’t go to bed worried that your barrel is made from Play-Doh.
Are any manufacturers audited by a 3rd party to verify any of their claims?
The only way to know that my CMMG and BCM barrels are 4150 is, well, that the respective companies say they are. That or sending one of their barrels off for alloy analysis. If I did that, though, and posted the results who’s to say my claims are any more genuine than the manufacturer’s? The lack of a trusted 3rd party to independently verify means you either trust what the manufacturer says or find another manufacturer, I guess. (Or you spend a boatload to constantly verify their claims.)
This is one situation where I think “The List” gets overly anal. Chrome-plated chrome-moly steel gets a check mark, but something like stainless would be “incorrect”?
Rather, people misusing The Chart™ for something other than its only useful purpose get overly anal. It would be incorrect…for an m4. If you’re not trying to reproduce an m4, you shouldn’t really care.
I agree, however, that some folks get wrapped around the handle about a part that’s going to be replaced anyway. If you do a lot of shooting. And if you don’t, it won’t matter.
As a Certified Flight Instructor, Advanced Aviation Ground Instructor, Commercial Pilot, and an aviation professional… I say you need to stop posting.
And don’t fly another plane or drive another car if the thought of cross-industry production scares you. The same companies that make automobile tires also produce aircraft tires, tank treads, and similar products across various industries and theatres. Those $150 GPS systems that you purchase for your daily commute to work? The same companies make the systems that fly multi-million dollar commercial aircraft on autopilot.
Sorry my opinions don’t sit well with others. Guess I’ll stop fixing the planes too. This might as well be my last post on the internet. God forbid everyone not agree with what I say. I only brought up that particular part because I know exactly how much it fails and causes me more work. I directly relate it to the manufacturer. Now the name might be off I’ll have to take another look at the part. As far as WWII most of the companies that took on government contracts completely stopped production of their civilian products and focused entirely on military ones. Like I said my opinion no need to crucify me for it.
Hugo Boss once manufactured uniforms for the SS. General Motors once manufactured M-16s. Mitsubishi manufactures bombs and airplanes for the JSDF. Saab makes submarines and fighter jets. Texas Instruments doesn’t just make calculators. And MIT does more than house Noam Chomsky.
Oh, and if you receive a bad part out of supply from Goodrich, be sure to QDR it. Sorry that you have to work B-1s… just think: you could be working C-5As, or AC-130Hs. I recommend HH-60s if you ever get the chance - they’re the best aircraft to work on, by far.
I ordered a CMMG upper from the Sportsmansguide a month ago and the first time at the range my weapon jammed, the forward assist parts came loose and jammed the bolt, it took almost an hour to break the small parts free to send it back to CMMG direct.
I called Garson @ CMMG and he took care of it ASAP and sent it back to me before my next Coyote Hunt the following week.
I never got a we are sorry for the problem you had with our product but, they did fix it…
As for the barrel, it groups nicely I had it out yesterday @ the range and I`m happy with it. No malfunctions / No pieces lodging in the weapon so …so far so good!
Later
Louie S.
And
Remember
A Firearm Should Be Considered A Fighting Weapon First.
Any Other Use Should Be Considered A Bonus !!
Perhaps you should, because as a former Air Force and current commercial pilot, it doesn’t sound like you can tell your A** from a hole in the ground. Lots of BF Goodrich parts on commercial jets. And I guess the Boeing jet I fly must be pre-WW2, since Boeing is the biggest military contracter the Air Force has.
I honestly don’t know; I have a DD Omega rail on it and can’t get to it at the moment (still at work). But if memory serves me right, it was something like “MP 1x7 twist”, and I think it said 5.56 somewhere. It was marked in the middle where the rail system covers it up.
Is there something in particular it should say? I can get pics up later.
Also, it was not a bargain bin or anything. It was one of their “government profile” uppers. I got it in the later part of 2008.
Another neat point to point out in reference to my “chart” question: the full-auto carrier came properly staked.
OK for recreational use is all well and good, but you also need to recall that not everyone here decided to plonk down $1000-$3000 for “recreational use”. Quite a few might even be using them on select-fire lowers for work.
Stainless steel is apples to oranges. The chart refers to M4 type rifles.
Well, i am aware of the technical limits of the steel, the question was: what does CMMG use, and who found out (and how/what evidence) that they don’t use the 4150 mil-certified steel they advertise.
Truth is, yes: most users - including most military applications - won’t notice a difference between 4140, 4150, and 4150 CMV Mil-B cert. steel, assuming it is chromed and properly made. The majority of military firearms (note: refering to other nations’ militaries and designs here) out there use 4140 and even 4130 steel in most major components; AK-47s are known as being unbreakable beasts, despite being made out of mostly “lower grade” material.
And milspec is nowhere near lowest bidder standards. In fact, it is quite the opposite: it is the “you must do all of these things this exact way; this is the absolute least we will expect this rifle to be made of” standard. And the scary thing is, comparing old firearms and even the original M16 TDPs, and even to the most modern designs’ TDPs that have been fielded as potential replacements, the M4 is quite overbuilt, from what it seems.
My lightweight barrel is super accurate, and has never given me a single problem. I have put about 1000 rounds through it, and I expect it will get above 10K before I think of replacing it.
Since there are some here who really get to shoot (I guess those guys have deep pockets or get ammo from the department - I can’t afford to shoot the number of rounds I would like to)…
Who has a bunch of rounds (say ~10K or more) through a CMMG barrel and what is your conclusion?
