C4iGrant said:
DPMS usually represents one of the lesser choices in AR's. Here is a good chart to show you where they line up compared to a mil-spec weapon.
Remember that not all AR's are created equal and that there is a standard (TDP) on how a fighting weapon is supposed to be built. It is great to go above the baseline, but to go below it is a no go.....
C4
that looks liek a chart grading how close to an M4 an M4 clone is. Which is worthwhile if what you want is an m4 clone.
Mil-spec means it's what the army wants, and not necessarily what's the best. It definitely doesn't mean it is the best for other purposes. DPMS has a lot of market share in the 3-gun world, and you can get nice reliable ARs from them.
The chart is comparing weapons against the TDP (not the M4). The TDP is the standard for how to build a fighting weapon. There are several ways to go above the TDP, but there are also many ways to go below it. I have never seen a DPMS AR go above the TDP (to date). The TDP also tells you to properly stake the gas key and castle nut. DPMS does neither of these things either at all or very well
The heavy buffer is a matter of taste and purpose of the gun. For a full auto using mil-spec loads with a carbine length gas system it is pretty much a must have. You shooting something else for a different purpose, it might not be the right choice. For a full length stock, you really don't need it. In the civilian world, ARs come in lots of flavors.
The H or H2 buffer is not really "personal taste", but more a matter of reliability. The heavier buffer increases lock time. While its main purpose is to help a FA weapon run better, it also helps a SA weapon run better.
The m16 carrier is not of much use when you don't have a full auto trigger group, and by going with different carrier designs and materials, you can acheive results that might suit your purposes much better.
The M16 BCG was what was designed for use in the weapon. This again adds weight and slows things down. There are better bolt carriers out though. JP tactical carrier comes to mind.
The balck spring insert indicates a heavier spring rate extractor spring. If people followed the rules. Of course it isnt' the only way to fix it, and also wasn't the original spec.
The black extractor insert does NOT indicate a heavier spring. To my knowledge, only in the CRANE upgrade kit do you find the black extractor with a 5 coil extractor spring. All A2's, A3's and M4's come with black extractors. These extractor inserts are far superior to the blue extractor inserts.
The 5.56 chamber is more reliable in the civilian world, but mostly you are feeding .223 ammo to it, and lose accuracy. If accuracy counts for you (say using your EBR as a varmint gun), then you probably want a .223 chamber. If you want to split the difference, you probably want a .223 wylde chamber. Depends on your plans for the gun.
Who is most likely feeding their AR's .223? I'm not! Reliability (on a fighting weapon) is more important than accuracy. We are also talking about such a small loss in accuracy, that most shooters would never know. All of my Noveske SS barrels have a 556 NATO chamber and shoot at least half inch groups.
I do agree that on a Varmint gun, a .223 chamber is most likely the best choice. On just about anything else though, it isn't worth it.
The 1:7 twist can be debated quite vigorously once you aren't talking a sub 16" SBR.
M4 feedramps are also of debatable benefit when not talking a full auto weapon. But they don't hurt.
It can be debated, but generally not by anyone that is looking at their weapon for a defensive purpose. I actually even doubt that a Varmint shooter could argue against a 1/7 twist once they look at the extended range a 1/7 twist shooting 77gr ammo can give them.
M4 feed ramps help with HP ammo and larger grain bullets. They are something that only help reliability of the weapon. So that makes them a must have in my book.
The mil-spec diameter receiver extension... well this is one place i wish everyone followed a single standard for dimensions. The real answer for most people is that you want it to match the stock you want on your gun. Which means you want it or don't wont it absed on situation.
The other dirty little secret about commercial RE's is that they they tend to be made MUCH cheaper and not nearly as strong as a mil-spec RE.
Staked castle nut. If you are in the deep thorws of black rifle disease you REALLY do NOT want a staked castle nut. Because you will be taking it off and putting it on multiple times, and it is a PITA when staked. If you are uncle same and your soldiers WILL be using the stock you gave them no matter what, then staking it is a very good thing.
Unstaking a castle nut is VERY easy. What is worse is too NOT stake it and then have it come loose on you. Then you start to lose springs and detents. The solution that most lesser quality AR manufacturers have gone to is to use red loctite on the threads. Do you know what Torque + red loctite equals?????????? That is a MUCH more permanent setup than ANY stake job could ever be.
Staking the castle nut is the only correct answer.
DPMS makes quality parts. Lots of those parts deviate from standards like their lo-pro upper receiver. This makes some people really happy, and others don't care. But the parts are sound and generally well made.
Can you tell me which DPMS parts are good? I would love to know as I have not seen any to date. Their barrel steel is 4140 (cheapest there is), they do not HPT or MP test their bolts or barrels and use commercial RE's.
I had a new DPMS M4 (
http://www.dpmsinc.com/firearms/5.56x45mm/ap4_carbine.aspx) come into the shop the other day. I had to ream the chamber as it was a .223. Notice in their specs, that it says they use a 556 chamber. This is a lie. The gas key and castle nut were not staked either and they used a blue extractor insert.
Companies don't cut corners like this to "improve" the AR design. They do it because it saves them money.
C4
