Various M4 makers and the features they offer
- Thread starter rob_s
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Eightball
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Nifty. You collect the data yourself, or find it somewhere and compile it?
Don't Tread On Me
Member
In my opinion, only Colt properly stakes the gas key. I don't feel that LMT's or CMT's method is as good. It might hold, but then again - so does Bushmaster's. It doesn't make it like Colt's. Colt's stakes are simply the way it should be, and should be considered THE standard.
Overall, that is a pretty darn good list. The 6920 would be a full blown M4 with 1] full auto parts 2] 14.5" barrel 3] standard trigger/hammer pins.
There's more to the M4 than just that. There's 6/3 rear sight on a mil-spec detachable carry handle. Many have junk handles or use an 8/3 rear dial. While NOT an M4gery, the 6520 ranks better than most of the rifles on that list. It has everything the 6920 does, but instead with an A2 upper and a pencil barrel instead of the M4 profile. Neither of which decreases its quality.
It is also a fact that Colt HPT and MPI tests each individual rifle along with its bolt/carrier. Other brands batch test.
There's also the issue about high shelf vs. low shelf lowers. Like the 14.5" barrel, pins, full auto parts - this doesn't effect functional quality or material quality. Other things listed do effect either material quality or function/performance. But from a purist's view, a milspec receiver would have the proper shelf and another hole drilled, although that extra hole could get the BATFE after you.
Might be nitpicking, but since this is a detail list - might as well have all the details. There's the flat head grip screw vs. hex head. Flat head is milspec.
IIRC, when the stock if fully collapsed, the receiver extension should NOT be flush with the butt. True M4 stocks are 4 position, not 6 position. Although, that does not hurt function or performance, might even help it.
Some rifles have plastic trigger guards. Milspec is metal.
Finally, a true M4 has a side mounted front sling. The 6920 is on the side, not on the bottom.
Overall, that is a pretty darn good list. The 6920 would be a full blown M4 with 1] full auto parts 2] 14.5" barrel 3] standard trigger/hammer pins.
There's more to the M4 than just that. There's 6/3 rear sight on a mil-spec detachable carry handle. Many have junk handles or use an 8/3 rear dial. While NOT an M4gery, the 6520 ranks better than most of the rifles on that list. It has everything the 6920 does, but instead with an A2 upper and a pencil barrel instead of the M4 profile. Neither of which decreases its quality.
It is also a fact that Colt HPT and MPI tests each individual rifle along with its bolt/carrier. Other brands batch test.
There's also the issue about high shelf vs. low shelf lowers. Like the 14.5" barrel, pins, full auto parts - this doesn't effect functional quality or material quality. Other things listed do effect either material quality or function/performance. But from a purist's view, a milspec receiver would have the proper shelf and another hole drilled, although that extra hole could get the BATFE after you.
Might be nitpicking, but since this is a detail list - might as well have all the details. There's the flat head grip screw vs. hex head. Flat head is milspec.
IIRC, when the stock if fully collapsed, the receiver extension should NOT be flush with the butt. True M4 stocks are 4 position, not 6 position. Although, that does not hurt function or performance, might even help it.
Some rifles have plastic trigger guards. Milspec is metal.
Finally, a true M4 has a side mounted front sling. The 6920 is on the side, not on the bottom.
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Don't Tread On Me
Member
I swapped out the A2 upper on my 6520 with a CMT M4 upper w/ M4 ramps (anodized). Now it is the perfect AR (for me). 
AR15barrels
Member
I don't think it's fair to compare LMT and CMT staking as being similar.
LMT's staking is every bit as good as Colt's staking.
CMT's staking sucks.
They just wack it with a punch across the top of each screw.
Here is a Colt:
(photo courtesy of skintop911 on m4carbine.net)
Now compare RRA and CMT/Stag:
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RockyMtnTactical
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Charts like this are stupid.
It's funny how some people see charts like this made up by one guy on the internet and all of a sudden it's an authority on AR15's...
Some of the stuff listed on that chart are straight up wrong and/or misleading too, although most of it is seemingly technically correct...
Some of the things listed mean something (like MPI'ed bolts, chrome lined barrels, etc...)... but...
A lot of the things listed on that chart mean absolutely nothing.
Seriously, does it matter if my AR is parked under the FSB? no.
Do the FSB pins need to be tapered? no.
Does it matter if I have M4 feedramps on my semi auto? no.
Do I need dual heat shields? no.
Is a 1/7 twist the optimal twist? Not to most.
Some will argue that high pressure testing will actually cause undo stress on the parts being tested...
Another thing to understand is that in some cases, not being milsepc can actually be better. One instance for example is that of LMT barrels, which are overbored. It's not milspec, but it makes for a much more accurate chrome lined barrel (better than Colt). Why isn't that on the chart?
Anyways, I could go on and on...
It's funny how some people see charts like this made up by one guy on the internet and all of a sudden it's an authority on AR15's...
Some of the stuff listed on that chart are straight up wrong and/or misleading too, although most of it is seemingly technically correct...
Some of the things listed mean something (like MPI'ed bolts, chrome lined barrels, etc...)... but...
A lot of the things listed on that chart mean absolutely nothing.
Seriously, does it matter if my AR is parked under the FSB? no.
Do the FSB pins need to be tapered? no.
Does it matter if I have M4 feedramps on my semi auto? no.
Do I need dual heat shields? no.
Is a 1/7 twist the optimal twist? Not to most.
Some will argue that high pressure testing will actually cause undo stress on the parts being tested...
Another thing to understand is that in some cases, not being milsepc can actually be better. One instance for example is that of LMT barrels, which are overbored. It's not milspec, but it makes for a much more accurate chrome lined barrel (better than Colt). Why isn't that on the chart?
Anyways, I could go on and on...
Don't Tread On Me
Member
LOL.
Means absolutely nothing? Well, the U.S. military and their decades of experience (centuries actually) and experts disagree with you. They dictate each and every little thing listed on that chart as part of their specification FOR A REASON. I used to question things like that as being silly, but it isn't silly simply because I was ignorant of the reasons why. Tiny differnces might mean nothing to you, but they might have caused a problem for some GI at some place at some time.
Rob_S. I have a similar set up, with Troy and the very same ACOG & mount. Just no rails ( have no need for them ). Nice rifle.
Means absolutely nothing? Well, the U.S. military and their decades of experience (centuries actually) and experts disagree with you. They dictate each and every little thing listed on that chart as part of their specification FOR A REASON. I used to question things like that as being silly, but it isn't silly simply because I was ignorant of the reasons why. Tiny differnces might mean nothing to you, but they might have caused a problem for some GI at some place at some time.
Rob_S. I have a similar set up, with Troy and the very same ACOG & mount. Just no rails ( have no need for them ). Nice rifle.
RockyMtnTactical
Would you like to know what is really stupid.........
It's obvious that you know little to nothing about The Different AR's and there spec's or the person who did the research and created this chart.
But believe it or not... there are those who seek out information like this and it is a valuable resource to them..
And you sell tactical gear to the the Military and LEO.????
WOW..... you sound like a stereotypical gun store counter dealer.....
If you have something positive to add.. please feel free.. if not........
Would you like to know what is really stupid.........
It's obvious that you know little to nothing about The Different AR's and there spec's or the person who did the research and created this chart.
But believe it or not... there are those who seek out information like this and it is a valuable resource to them..
And you sell tactical gear to the the Military and LEO.????
WOW..... you sound like a stereotypical gun store counter dealer.....
If you have something positive to add.. please feel free.. if not........
RockyMtnTactical
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- 3,539
OK, go ahead and explain to me how all of those features mean something, why and how.
One instance that I will mention right off the bat is, I don't shoot M856 tracers in my AR15's, so why do I need a 1/7 twist? What is it about the 1/7 twist that means something other than shooting tracers? I have a 1/7 barrel, and it's simply not the greatest. I wish it were in 1/9. 1/9 or 1/8 would be best for ME, for the rounds I tend to shoot. Likewise, most people tend to shoot 55gr to 62gr bullets and that is why the 1/7 is not the greatest twist rate for me and many other people.
Dual heat shields would be nice if I had a F/A. But I don't, and none of the rifles being sold to civvies brand new right now are either... so why do I "need" dual heat shield handguards? I've put 1000 rounds downrange in a day and never felt like I needed dual heat shields. i.e. How is this as important as have a correctly stake carrier or a chrome lined barrel?
Similarly, M4 feedramps are nice in a F/A.... but I don't have a F/A... they won't hurt anything to have, but that doesn't mean that they are some huge upgrade that we all need to have in our AR15's.
4150 steel is nice... but it's not nearly as important as having a chrome lined barrel.
The CTR is twice the stock the standard 6-position stock is, but I guess since the 6-position stock is "milspec" I should just stick with that? If it's milspec, it should be more than good enough right?
That's just me criticizing the list itself and it's supposed "awesome mall-ninja features"...
Like I said, some of those things matter, a lot. Some mean nothing! Keep in mind, I like LMT's and CMT's in general (the CMT staking jobs can easily be fixed, it's a 5 minute job). Mostly because they are high quality AR15's. They take more precautionary measures than some of the others. I don't really love Bushmaster, DPMS, RRA, or Oly or anything else that is generally cheaper... They don't take as many precautionary measures.
I'm just saying that the list there seemingly makes a big deal out of some stupid things that don't matter and lists it right along with some things that do matter. That alone seems misleading. Sure, list the things that matter, but listing things that matter that are "milspec" and things that don't matter that are milspec is kind of stupid.
That is not to mention that some of the information on the list is straight up incorrect/false. If the list were 100% correct, I probably wouldn't think the list was quite as stupid, but why make a list of incomplete and false information??
I could go over every single one, but I just don't have the time right now... and to be honest, it would be kind of boring and painstaking... but just to name a few right off the bat, it mentions that some manufacturers do special runs of 4150 barrels in 1/7, etc... Stag does this, but they don't mention it on the chart. You can get H buffers for Stag's as well...
Also, as far as "reports of part not meeting spec", that's just silly, you could mark that for every single manufacturer of every rifle... Everyone has put out a lemon...
I could go on...
I understand the thinking that the list is suppose to be helpful to people looking to buy or know more about AR15's, but it's kind of useless unless you are (1) explaining why it's important for the part to meet that milspec requirement or exceed it, and (2) making it 100% complete and up to date.
One instance that I will mention right off the bat is, I don't shoot M856 tracers in my AR15's, so why do I need a 1/7 twist? What is it about the 1/7 twist that means something other than shooting tracers? I have a 1/7 barrel, and it's simply not the greatest. I wish it were in 1/9. 1/9 or 1/8 would be best for ME, for the rounds I tend to shoot. Likewise, most people tend to shoot 55gr to 62gr bullets and that is why the 1/7 is not the greatest twist rate for me and many other people.
Dual heat shields would be nice if I had a F/A. But I don't, and none of the rifles being sold to civvies brand new right now are either... so why do I "need" dual heat shield handguards? I've put 1000 rounds downrange in a day and never felt like I needed dual heat shields. i.e. How is this as important as have a correctly stake carrier or a chrome lined barrel?
Similarly, M4 feedramps are nice in a F/A.... but I don't have a F/A... they won't hurt anything to have, but that doesn't mean that they are some huge upgrade that we all need to have in our AR15's.
4150 steel is nice... but it's not nearly as important as having a chrome lined barrel.
The CTR is twice the stock the standard 6-position stock is, but I guess since the 6-position stock is "milspec" I should just stick with that? If it's milspec, it should be more than good enough right?
That's just me criticizing the list itself and it's supposed "awesome mall-ninja features"...
Like I said, some of those things matter, a lot. Some mean nothing! Keep in mind, I like LMT's and CMT's in general (the CMT staking jobs can easily be fixed, it's a 5 minute job). Mostly because they are high quality AR15's. They take more precautionary measures than some of the others. I don't really love Bushmaster, DPMS, RRA, or Oly or anything else that is generally cheaper... They don't take as many precautionary measures.
I'm just saying that the list there seemingly makes a big deal out of some stupid things that don't matter and lists it right along with some things that do matter. That alone seems misleading. Sure, list the things that matter, but listing things that matter that are "milspec" and things that don't matter that are milspec is kind of stupid.
That is not to mention that some of the information on the list is straight up incorrect/false. If the list were 100% correct, I probably wouldn't think the list was quite as stupid, but why make a list of incomplete and false information??
I could go over every single one, but I just don't have the time right now... and to be honest, it would be kind of boring and painstaking... but just to name a few right off the bat, it mentions that some manufacturers do special runs of 4150 barrels in 1/7, etc... Stag does this, but they don't mention it on the chart. You can get H buffers for Stag's as well...
Also, as far as "reports of part not meeting spec", that's just silly, you could mark that for every single manufacturer of every rifle... Everyone has put out a lemon...
I could go on...
I understand the thinking that the list is suppose to be helpful to people looking to buy or know more about AR15's, but it's kind of useless unless you are (1) explaining why it's important for the part to meet that milspec requirement or exceed it, and (2) making it 100% complete and up to date.
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Can you please tell me which things are "wrong and/or misleading" so that I can make corrections?
As to one thing being better than another, you're projecting. All I've done is list the features that various major-brand ARs have and checked off boxes for which ones have them and which ones don't. I've made no judgment call as to which is better or worse, I've simply provided a resource for people, should they be in the market for a new AR, to make an informed decision instead of relying on lies and half-truths from unscrupulous dealers and internet-commandos with an agenda.
I want this chart to be as accurate as possible, so please identify which items are incorrect and provide photographic or other documentation of same.
While that may have been the original intention, 1:7 barrel twists help to stabilize the heavier (longer, actually) rounds like the 75 and 77 grain Black Hills and TAP which are more accurate and have better terminal ballistics.
If you've never fired a semi-auto AR enough to get the single-shield handguards hot enough to hold you're doing something wrong. And I'm not talking about bump-firing or spray-and-pray either.
First, M4 feedramps can't hurt, can they? So why don't the other makers bother to use them? As to giving weight to one feature over another, that's back to making a judgment call. This chart is simply a collection of facts.
Again, you've missed the point. The issue here is the OD of the receiver extension and it's compatibility with aftermarket stocks. Magpul was nice enough to manufacture two versions of the CTR so that people with non-spec receiver extensions can easily install their stocks, but those that want an LMT or Vltor will have to replace their receiver extension if it's non-spec adding cost to their "budget" AR.
The list is neither stupid nor is it smart. It's a list of fact. Period.
Again, please enlighten me. So far even the assumptions you've made (see above) have proven to be wrong.
Can you provide documentation of this in some way? I would be happy to add a "2" in those boxes if it can be verified.
You're missing the point. What we're talking about here is whole batches of rifles being uncovered that have problems or do not meet the manufacturer's claims, not an individual lemon.
PracticeFreedom
Member
I myself wouldn't say there's anything wrong, but there is stuff missing (like Bushmaster's plastic trigger guards) as well as misleading.
The misleading part is scoring all these things equally.--or perhaps scoring at all
To me, something like chrome-lining or having the barrel made out of the correct steel are far more important than, for example, the above mentioned hanguard double-shielding---that's a cheap fix.......re-barreling isn't
RockyMtnTactical
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I have no agenda, I just like people to get what they want/need and hopefully get the best deal on top of it. For most people, CMMG, Sabre, Stag, S&W, and LMT make the better ones for the money. Many of these cost as much as a Bushmaster which I don't think is quite as good, yet Bushy gets a lot of business... Yet Bushmaster has some things on the list that Stag and LMT don't have... and people seem to believe that Bushy is great... that's not to say that Bushmaster hasn't put out a good weapon or two... But they don't make as good a weapon as LMT or CMT...
You're just more likely to get a better deal and a better rifle if you buy one of those that I listed as opposed to Bushmaster or DPMS...
I like quality, I do, I just believe that this list is possibly doing a disservice to some people by being misleading and not explaining the importance of the features that you feel are so important... It would mean more if it had an explaination. That way people could really decide which of these rifles they really should consider and why.
You're just more likely to get a better deal and a better rifle if you buy one of those that I listed as opposed to Bushmaster or DPMS...
I like quality, I do, I just believe that this list is possibly doing a disservice to some people by being misleading and not explaining the importance of the features that you feel are so important... It would mean more if it had an explaination. That way people could really decide which of these rifles they really should consider and why.
coyote_jr
member
Was that a commercial for Colt?
AR15barrels
Member
I have to agree with this.
Dump the scoring so un-informed people don't think that taper pins are just as important as proper carrier staking or 5.56 chamber.
Quote by RockyMtnTactical:
No, the chart is just a compilation of data, contributed to by many knowledgable people.
Your whining is based on potential uses/interpretations of the data.
Perhaps you could contribute by correcting what you perceive to be incorrect data.
Mark
No, the chart is just a compilation of data, contributed to by many knowledgable people.
Your whining is based on potential uses/interpretations of the data.
Perhaps you could contribute by correcting what you perceive to be incorrect data.
Mark
Boanerges57
Member
Wow.. does anyone else sense some hostility here?
Um... didnt the man say it was simply a collection of facts?
Colt makes very fine weapons. That is a fact.
I dont own a colt. I dont even want one. They dont make one the way I like, but generally the quality of what they do make is excellent.
The 1:7 twist has never noticably affected the accuracy of my weapon and ive qualified expert with both M16A2, M16A4 and M4. Ive heated a dual heatshield up on semi-auto but I wasnt buying the ammo
The list as I see it is similar to a list featuring car specs: one has AC another doesnt, some are manual others automatic... what you want, what you can afford and what you really need are the main constraints.
He simply made a list. If you are offended by lists im sure there is an anti list forum somewhere.
It is sometimes a benefit to know and understand features available.
If you dont want to see the chart DONT LOOK!!!
_______________________________________________
The government is not out to get you, they already have you and this is just a horrible dream....
Um... didnt the man say it was simply a collection of facts?
Colt makes very fine weapons. That is a fact.
I dont own a colt. I dont even want one. They dont make one the way I like, but generally the quality of what they do make is excellent.
The 1:7 twist has never noticably affected the accuracy of my weapon and ive qualified expert with both M16A2, M16A4 and M4. Ive heated a dual heatshield up on semi-auto but I wasnt buying the ammo
The list as I see it is similar to a list featuring car specs: one has AC another doesnt, some are manual others automatic... what you want, what you can afford and what you really need are the main constraints.
He simply made a list. If you are offended by lists im sure there is an anti list forum somewhere.
It is sometimes a benefit to know and understand features available.
If you dont want to see the chart DONT LOOK!!!
_______________________________________________
The government is not out to get you, they already have you and this is just a horrible dream....
gdvan01
Member
As a recent and first time owner of an AR, I have to agree with the following:
When I got to the point that I was ready to build out an AR, after much reading on various sites, I was mostly confused about many of the options. I spent time asking the fine folks at Frederick County Firearms about each part and their advantages/disadvantages. M4 feed ramps always comes to mind....
Anyway, I think the main duty is on the person to decide upon the particular application for the weapon and choose the components that are suited for the intended task. I could have purchased one of the several that were ready to go in the store but I already had an idea of what I wanted, I just needed clarification from those that were already knowledgeable and could explain the features.
When I got to the point that I was ready to build out an AR, after much reading on various sites, I was mostly confused about many of the options. I spent time asking the fine folks at Frederick County Firearms about each part and their advantages/disadvantages. M4 feed ramps always comes to mind....
Anyway, I think the main duty is on the person to decide upon the particular application for the weapon and choose the components that are suited for the intended task. I could have purchased one of the several that were ready to go in the store but I already had an idea of what I wanted, I just needed clarification from those that were already knowledgeable and could explain the features.
RockyMtnTactical
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It's not about "not looking" for me. I'm worried about others who read it who may be misled.
All I did was point out facts and some of the false and misleading info in that chart. I think it's misleading and I don't believe that mentioning the features as a positive w/o mentioning the reason for why it's desirable or "better" is a good idea. It leads people to believe that some of those features are preferable for the average shooter, and that is simply not true.
I don't like that people post charts that are not 100% accurate and up to date. I mentioned a couple issues to start. I verified this information from the source. If you want to know for yourself, go to the source and find out for sure. If you have the desire to know for yourself, you'll do that instead of look for random sources on the internet.
I'm not trying to be "hostile". I'm trying to be helpful. I'm not trying to be rude. Sorry if I have come across that way. That was not my intent.
In the end, I think we both probably feel the same about buying higher quality AR15's. Like I said, I prefer LMT and CMT, personally. I simply don't believe in making a fuss over which AR15 uses tapered FSB pins, etc... It's nonsense.
All I did was point out facts and some of the false and misleading info in that chart. I think it's misleading and I don't believe that mentioning the features as a positive w/o mentioning the reason for why it's desirable or "better" is a good idea. It leads people to believe that some of those features are preferable for the average shooter, and that is simply not true.
I don't like that people post charts that are not 100% accurate and up to date. I mentioned a couple issues to start. I verified this information from the source. If you want to know for yourself, go to the source and find out for sure. If you have the desire to know for yourself, you'll do that instead of look for random sources on the internet.
I'm not trying to be "hostile". I'm trying to be helpful. I'm not trying to be rude. Sorry if I have come across that way. That was not my intent.
In the end, I think we both probably feel the same about buying higher quality AR15's. Like I said, I prefer LMT and CMT, personally. I simply don't believe in making a fuss over which AR15 uses tapered FSB pins, etc... It's nonsense.
Bobarino
member
Bushmaster does have "properly staked" gas key. i don't have my camera with me and really don't feel like disassembling mine, but the gas key looks virtually identical to Don't Tread On Me's.
Bobby
Bobby
Unacceptable. Data was presented. You challenged that data as being inaccurate. The burden is on you to present documentation of your claim.
I will gladly change the chart if it's shown to be incorrect, but if I changed it everytime somebody whined "it's not right!" without any documentation we'd never get anywhere.
Specifically, I'd like you to show where you got the following:
jacketch
Member
There will always be lots of "my self esteem is all tied up in my rifle and you shot it down" types. The facts speak for themselves and unless someone can document that errors are shown on the chart, it provides valuable information for anyone willing to research the importance of the items listed.
I wish it had been available years ago when I was first looking into purchasing an AR15.
I wish it had been available years ago when I was first looking into purchasing an AR15.
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