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[ARCHIVED THREAD] - Good Mil Spec Explination From RRA (Page 1 of 2)
Posted: 7/11/2007 9:08:34 AM EDT
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It depends on what you refer to as "Mil-Spec". Even though it is completetly erroneous to use it this way, for many people"Mil-Spec" now means "does it have parts interchangabilty within our brand and with other brands"...in which case yes, RRA products meet that criteria. I would call that "industry standard" though, rather than "Mil-Spec". To be legally responsible, I have to say that only Colt and FN-USA (and any contractors/sub-contractors they use under the terms of nondisclosure agreements (and the threat of federal law) have the government TDP (technical drawing packages) which contain the actual "Mil-Specs" and can only be used on rifles and/or their component parts made for the military. EVERY other manufacturer has to come up with their own drawings and specifications/tolerances on parts. Also, there is no "Mil-Spec" for many components on AR-style rifles...unless the governement has taken the time and effort to come up with an actual spec, do the drawings, submit it for a MS number, etc...there is no "Spec" on it. Example...rails. There is a spec (MS1913) for the rail itslef, there isn't for the quad rail handguard that the rail is a part of. Varmint and other non-standard barrels, mid-length gas systems, muzzle brakes, semi-auto and match trigger groups all come to mind as common componnets that don't have a "Mil-Spec". About the only thing that I know of that there is any kind of current "controversy" over is the carbine receiver extension (buffer tube). There are two specific diameter of tubes in use...commercial and military. We, as do many other manufacturers, do use the commercial diameter..as did almost every commercial manufacturer except Colt for more than thirty years. It has only really become an issue within the past few years as a plethora of new stocks have hit the market, many of which require the small diamter military tube. Both tubes retainthe same thread pitch and diameter, and will fit in the same lower receivers. It is strictly a function of what diamter the sliding portion of the stock will be and whether or not it will fit correctly (or at all) on the extension in use. We also use 4140 moly rather than 4150 in the barrels. For most shooters the extra carbon content isn't really needed, and for the full-auto crowd we always stress going chrome-lined, in which case the 4140 versus 4150 discussion is also largely immaterial. Hope that helps..although it may not win you any bets. |
 That's the guy that posted a "swan song" "I'm leaving arfkom to spend my time in better ways" post on 11/6/2004 and then opened a new account with a different name on 11/16/2004.www.ar15.com/member/member.html?id=62764 www.ar15.com/member/member.html?id=1051 Last I knew Armalite used 4150 |
And had 5.56 chambers |
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That was originally posted in the RRA Industry Forum as an answer to a question by an ARFCOMer. As far as the chart goes, several aspects are incorrect. As far as the RRA line, bolts are randomly tested for MPI and pressure. If any ina batch are questioned, the entire batch is checked. We've used black extractor inserts and appropriate springs for years. The front sight base is the correct "F" height, but not all are marked as such, the model in question has always been standard with a 5.56mm NATO chamber, and an "H" buffer is optional. Steve/RRA |
And had 5.56 chambers I think RRA has chrome lining as a readily available option, I would not describe it as being only available on special runs. edit Steve's comment about testing is also true as to Bushmaster, I think. edit2-whoops did not look at the specific model number |
| And whats this about CMMG advertising 4150 steel in thier barrels and not using it? Ive never heard of that, what are these reports of them not using the materials they advertise. If this is true id like to see some proof. As far as the others, BM, Armalite, DPMS, RRA, well, we all know they are very far from MIl-spec. |
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Don't shoot the messenger. I would like the chart to be as technically correct as possibly myself so I can use it as an accurate teaching aide. Sorry no linkee to the site of he who had to be thrown off arfkom ;)-Aimless IM me for the link that can't be posted here. |
Armalite tech note concerning their chambers |
Armalite's statement of barrel material is about 3/4 of the way down that page. |
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+1 - this is a great chart to keep current. I would've found it useful while shopping around. I've heard reports that S&W M&P15A and T models are now coming with LMT manufactured BCGs. Can anyone confirm? Also, I understand that LMT 10.5" uppers are parked under the FSB, but 14.5" and 16" are not. A minor distinction, but perhaps one worthy of a footnote. |
I'll bet you my $40 tear-down and rebuild charge that LMT 10.5" barrels are NOT parkerized under the FSB. Shall I go tear one down this evening and take a picture for you? |
biggerhammer.net/picatinny/    |
You don't have to. I had my FSB off my LMT 10.5 5 days ago replacing a gastube and it was most definatly NOT park'd under the FSB. I'd bet your fee and my post count on it 
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Damn you for spoiling my bet.  I had to tear one down anyways. Someone wanted an upper built. I could have gotten TWO people to pay me to tear down that upper. That would have been sweet! 
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No, that's the old spec. Not the new spec that RRA uppers are made to. 
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This chart is not correct. For example: Armalite has properly staked gas key, M4 feed ramps, 5.56 chamber. Colt 6920 does not use 4150 barrel steel. I called Colt customer service and specifically asked if they use 4150 barrel in 6920. The answer: proprietary Chro-Moly-Vanadium steel. Check the price of the same profile Colt chrome-lined barrel and the other brand 4140 or 4150 chrome-lined barrel. You're not paying just for the Colt name or logo. |
We need Paul from Bravo Company to come educate us on the differences between 4150 and CMV steels. They ARE different, but 4150 is damn close to being CMV. |
I don't get your point. Your linked page Armalite states their CM and chrome-lined barrels are chambered in 5.56 and that their SS Match rifles are chmabered using a modified SAAMI chamber (probably a Wylde, but that's just a guess). Am I missing something? Are you suggesting Armalite does not offer 5.56-chambered barrels? |
Some of the items on the chart are very subjective. We could argue for days if it mattered if the barrel is parkerized under the FSB or attached with taper pins. I don't hold either of these as being important enough to base a purchase decision on. The "properly staked" item is also VERY subjective. Remember, the chart is just some guys opinion. Many of the items on it are facts that you can independently verify though. Overall, it's a very good piece of work. |
No, I missed something. I did not read that last line closely enough when I skimmed it the first time. I only saw the line above it about "modified SAAMI". |
But too many people get caught up on the F-Marked front sight base, mill-spec extension tube, etc, and will come on a website and say that Bushmaster/RRA/Etc. sucks because they don't have mill-spec extension tube. Give me a break. If it goes bang, it is good to go. Any company can have a lemon once in a while. That is why you test out all of your equipment and see if it works. Unless you plan on getting a Vltor stock or a stock that that requires mill-spec extensions, can anyone tell me why it is so important to have a Mill-spec extension? What's wrong with the Bushmaster or RRA collapsible stock or the A2 stock? I can care less about F-Marked front sight bases since I prefer flip up BUIS on the front and rear, but I never had any problems with my bushmaster that had a regular front sight base. |
Or an LMT Sopmod, or a Magpul CTR until recently... The commercial extension limits your stock choices. Personally, I like the commercial extension as it's thicker, but that's not what uncle sugar and Colt settled on... F-height front sight bases ARE important if you want to run a fixed front sight and a flip-up rear on a carbine without having to run a special post. It's up to EACH INDIVIDUAL to decide if these things are important to them or not. Without educating people, they would not HAVE THE OPTION of deciding. They would just use what Bushmaster shoves down their throat and then post questions like "why won't my front sight zero to my new BUIS?" or "why won't my LMT Sopmod stock fit on my carbine?" None of these things effect me, I'm a 3 gunner... 
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I absolutely agree with the F-Marked front sight base. But as long as people understand the differences, it shouldn't be a problem. If I wanted to get a Vltor stock, I know that I have to get a mill-spec tube. It doesn't mean that the regular tubes suck, it just means that they won't work with the Vltor. Ad that is my point. Too many guys just say something sucks just because it is different than a Colt. |
Where did you get that magwell grip? I've been looking everywhere for one. |
It's not a grip. It's an extended magwell. It greatly aids reloading. Manufactured by Ralph Arredondo. Sold by Brownells here. |
That would be the 1913 spec. |
Circa 2001-2002 or so, RRA was selling a bunch of out of spec flat top receivers on their carbines. This was noted in several threads here on arfcom. RRA then went into this whole fictional story about how their receivers were being made to the new picatinny spec and this new spec was going to be announced at the SHOT Show. Well, it was all a lie to cover for the fact they had a bunch of out of spec parts. Word on the street has it these same guys (former Armalite employees now at a company named after a river) are the ones who stole Armalite's AR-10 plans and gave them to ASA. That ended up in a Federal court case which ASA settled before trial. |
[ARCHIVED THREAD] - Good Mil Spec Explination From RRA (Page 1 of 2)
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