Long Range/Compact AR

[porscheboy]

Okay, so I just recently finished building the lower assembly to my AR. It has a Smith and Wesson M&P lower, AR-Stoner Parts kit, Magpul MIAD Grip, and Magpul MOE stock. (Magpul Products in Dark Earth). And now I'm turning my attention to the upper. At first I though I wanted a 16" Carbine style rifle with rifle length quad rail. But after some thought, It occurred to me that I have no practical use for an AR carbine! So I now plan on ordering a 24" barrel off of Midway and a rifle length Rail system. This is all great, but my question is will the magpul MOE stock be sturdy and solid enough for long range shooting? This is my first AR/build and need some help!

-Thanks In advance

 

[Dionysusigma]

It's... unusual, but it should work fine. Last time I shot my 20" AR, I swapped it with a spare complete lower that has a Magpul UBR stock on it. Nothing out of the ordinary, aside from that it just seemed odd.

Pics are required upon completion, of course.

Edited to add: The Canadian military's C7A2 rifle is pretty close to what you're describing, actually.

 

[chrome_austex]

Some people were proclaiming that you needed a consistent cheek weld to shoot at long ranges with high accuracy, and that the collapsable stocks were ill-suited for this.

That said, I shoot a little highpower competition, and have a 20" AR with a Magpul CTR on it (with no riser), and I feel like cheekweld is the least of my consistency concerns. I assume that the CTR is a bit 'sturdier' than the MOE due to the friction lock, but I wouldn't worry about it much.

I think the consistency and geometry of where the gun meets your shoulder is probably way more of a factor than any forward/back play in the buttstock or inconsistency in cheek weld. Just my 2c.

 

[taliv]

all the magpul stocks give you a decent cheek weld. the CTR/MOE are very light though, and not well-balanced with a 20" barrel and rifle handguard. if you're shooting off a bench/prone, that won't matter much. offhand, you'll have to use a little more muscle

 

[Lovesbeer99]

I'm building a smilar rig, but I'm looking for an ultra light so I'm using an Ace Skeleton stock and I'll get a 20" fluted barrel and the forend is very light weight. This will be a bench or prone gun so balance is not a high priority.

By the way, don't buy a barrel 'till you've checked out the White Oak options. The are great barrels and less expensive then most other premium barrels.

 

[Birddog1911]

For Pete's sake, a longer barrel does not equal accuracy, folks! Don't believe me, just look at the Mk12 platform with the 18" barrel. I know of at least one confirmed kill at 790 yards with a Mk 12.

A longer barrel gives you more velocity, not more accuracy. Keep that in mind when you're thinking of putting a yard stick on the end of your rig.

And I second Lovesbeer's comment about the White Oak barrels.

 

[mc223]

I shoot a White Oak 26 in. It is difficult at best to say that length only equates to velocity, as The White Oaks do shoot quite well.


Back to the original post

 

[madcratebuilder]

For Pete's sake, a longer barrel does not equal accuracy, folks! Don't believe me, just look at the Mk12 platform with the 18" barrel. I know of at least one confirmed kill at 790 yards with a Mk 12.

A longer barrel gives you more velocity, not more accuracy. Keep that in mind when you're thinking of putting a yard stick on the end of your rig.

And I second Lovesbeer's comment about the White Oak barrels.

This.

If you are shooting irons it may give you a longer sight radius depending on how you set it up. I see a lot of guys doing very well with 18" barrels in 5.56, 6.x and 7.62. If you are trying to keep the bullet super sonic past 1200-1400yds than you want all the barrel length you can carry. I built a 1200yd rifle and I'm still learning to shoot it at 600 yds. You get in the field and the wind is moving at all you are in for a rude awakening.

 

[Robert]

18 to 20" would be perfect IMO. Anything longer just gets unwieldy. I like the fixed stock myself but it is your rifle so go with what makes you happy. Whatever length you go with by all mean use a float tube rather than hand guards.

 

[C-grunt]

Also remember that a rifle length barrel/gas system should be mated to a rifle reciever extension, ie buffer tube.

 

[TonyAngel]

Unless you're shooting iron sights, I see no reason to go with a 24" barrel. A nice compromise among velocity, accuracy and smoothness would be to go with an 18" barrel with a rifle length gas system.

As for the stock, I don't know. A couple of guys seem to feel that it doesn't make much difference. I think it does. Whether shooting standing, at the bench or prone, the MOE (or similar stocks) suck for purposes of precision shooting. Having a light rear end on a rifle makes the rifle behave differently. I like to have some heft in the back end. I run a Magpul UBR. I like it a lot.

You can build anything you like, but if you want the rifle to handle well in a variety of situations, you have to keep it balanced or (as I prefer) back heavy.

BTW, unless you're going with a Shillen or Krieger or other brand name that Midway sells, look someplace other than Midway. For the money you could do better. For around $300, I'd be looking at either White Oak or Bravo Company SS410. I'd lean toward the Bravo Company though.

 

[Lovesbeer99]

I agree with TonyAngle. I posted earlier that I planned to build an ultralight rig specifically to shoot from prone with a bipod or from a bench. I want it light but it doesn't have to be balanced.

By comparison I also shoot NRA highpower in service rifle and my rig is pretty heavy. For the various positions I'd rather have the gun balanced at 17 lbs then unbalanced at 9lbs, especially for the standing position. If you're looking for an all purpose rig I'd consider something well balanced.

 

[Zak Smith]

Also remember that a rifle length barrel/gas system should be mated to a rifle reciever extension, ie buffer tube.

False.

For balance, I would not recommend one of the "CAR" style stocks, such as the CTR, SOPMOD, etc. The UBR has a better cheek weld since the top does not move, and it is a bit heavier as well.

 

[C-grunt]

False.

For balance, I would not recommend one of the "CAR" style stocks, such as the CTR, SOPMOD, etc. The UBR has a better cheek weld since the top does not move, and it is a bit heavier as well.

Really? Thats not what Ive been told before.

Also if a carbine extension and buffer/spring would work why hasnt the military, until now with the A5, gone to a collapsible stock on the m16? Even the A5 uses a longer extension than the carbine system.

 

[Zak Smith]

One can only speculate why a huge bureaucratic organization does or doesn't do something.

The Canadian C7A2 is a full 20" rifle with a carbine stock system.

 

[henschman]

I am doing something similar... I am going more for of an all-around battle rifle than long range precision, so I want to keep it light.

I am going with a BCM 20" Gov't profile upper, which is very lightweight compared to all those heavy barrels everyone is recommending, along with being chrome lined for reliability and corrosion resistance. I also want a collapsible stock... I am going with the Vltor E-mod. It is not as light as a CTR or MOE, but it is not as heavy as a PRS or UBR, and it gives you a lot of storage. Plus it is very solid. I figure it will balance well with the light profile barrel. I plan on using a 12" MI-SS free float tube on it, which will help keep the weight down and allow me to use rails only when and where I want them. I will leave the fixed front sight on the barrel, and put my sling swivel on the FF tube... that way I won't be pulling my front sight when I'm slung up and using irons. I will top it off with a TA-31 RCO A4 ACOG, and I will use my KAC 2-600m flip up rear sight... that is, if I get it back in one piece from my friend who is borrowing it and taking it to Afghanistan!

Yeah, you don't see a lot of rifle-length AR's set up with collapsible stocks. I guess most guys either want a close quarters carbine or a heavy long range precision rig. Me, I want an all-around battle rifle that is light and maneuverable enough, but that has the longer max effective range and better sight radius of the rifle length setup.

Now for the question about using a collapsible stock for long range marksmanship. When it comes to precision shooting, consistency is key. You want to always make sure you have the same sight alignment and sight picture for every shot. The reason a collapsible stock can present problems is because if you change the length of the stock, it moves your head and changes your sight alignment/picture. You can do just fine with a collapsible stock though... the key is to find which position works best for you and then always use that position when you are shooting with a particular optics setup. Stay consistent.

Lots of AR shooters put their nose on the charging handle to stay consistent. With a collapsible stock, I like to find the stock position that puts my nose on the charging handle when my neck is stretched out as far forward as it will go, and then mount the optic so eye relief is perfect when I'm in the prone position with nose to charging handle. You can then mark that stock position, or just remember it.

 

[Zak Smith]

Versatile setup- 17", RLGS, carbine receiver extension, UBR.



Been shooting that one since 2004. Here's the new one


That setup was put together for the style of 3-Gun matches we have around here: close and fast, to mid ranges (200-300), and some targets way out there at 300-600 yards. RLGS with slightly lightweight bolt carrier (and regular carbine buffer) is very mild recoiling and does not get off target, very reliable. 17" is short but can still use RLGS. I can set the stock at position 4 for more prone shooting or position 2 or 3 for more "on the move" stages. When new, the tan one shot 1/3 MOA with BH 75gr. The tan one has been shot continuously in matches since '04, local and big/national matches. The black one I use in big matches only now.



article | Evolution of the 3-Gun Practical Rifle

 

[madcratebuilder]

Also remember that a rifle length barrel/gas system should be mated to a rifle reciever extension, ie buffer tube.

Quote:
Also remember that a rifle length barrel/gas system should be mated to a rifle reciever extension, ie buffer tube.
False.

Ideally you want to match action spring and buffer weight to the gas system regardless of what barrel and stock is used.

 

[LAK]

With a low recoil cartridge like the 5.56/.223 a cheekweld is not critical at all from a control and comfort standpoint.

As far as accuracy is concerned it is consistant central eye placement in relation to the line of sight in the scope so that parallax is not an issue.

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Je Suis Prest

 

[Tirod]

The OP has switched horses in the middle of the stream. He's jumped in a built a nice short track chassis for autocross, now he wants to run LeMans.

Anyone can build what they want, the more focused the goal, the better the results. I'd suggest putting on the brakes and give a month or two, literally. Impulsively switching the task list won't put together a firearm that will work out good for either one or the other goal. At this point changing one's mind back in two more week's is highly possible.

We can advise and chafe at contradictory suggestions, or get this jelly nailed to the wall. Until it sticks in one place, tho, not much is really going to help.

A CQB lower with 24" ultra long range precision upper? It's not an optimum combination for either, let's not try to finesse mating a dachshund with a greyhound.

 

[TonyAngel]

18" barrel with rifle length gas system with carbine length buffer/UBR stock.



It works really well. It shoots very mildly. Double taps are very easy. It's very portable. I don't know that I'd call it compact, but it's very manageable. It comes in right at 10lbs as you see it, plus ammo.

 

[Zak Smith]

Ideally you want to match action spring and buffer weight to the gas system regardless of what barrel and stock is used.

There's not really much "matching" to be done. An M4 up to a 24" varmint upper will work properly with either a carbine receiver extension tube & buffer, or a rifle receiver extension tube and buffer, and the proper respective op spring. If the upper or magazines cause problems, the most common problems can often be masked by either going to a rifle receiver extension system or using a heavier buffer and/or bolt carrier. The M4 gas system is particularly short (see ArmaLite timing, pressure, temperature study and others) and to mask that problem some adjustments are made. But that's besides the point of saying a RLGS system must be matched to a rifle receiver extension tube, which is false.