A question for experienced shooters

AR/M4 AR General Discussion
1

I am hoping to complete a build I have been working on for the last year or so in the near future and of course I’m second guessing myself at the last minute. The original plan was to build two rifles, the one I am currently working on and a second lightweight variant later on, but now I am wondering if the minute differences between the two warrant two separate rifles or if I should just “meet-in-the-middle” so to speak.

Both rifles would share the following major components:
[ul]
[li]Magpul STR[/li][li]Vltor A5 buffer system[/li][li]Forged lower receiver[/li][li]Vltor MUR1A[/li][li]LMT E-carrier w/ standard bolt[/li][li]Raptor charging handle[/li][/ul]

The first build will have the following components:
[ul]
[li]Geissele SD-E trigger[/li][li]Noveske 16" Recon barrel w/ pinned Switchblock[/li][li]13.5" NSR (modified to accept SB)[/li][li]1-6x variable scope[/li][/ul]

The lightweight variant will substitute the previous components with the following:
[ul]
[li]Geissele SSA trigger[/li][li]Noveske 14.5" Skinny Contour CHF barrel w/ pinned gasblock & pinned flash hider (or similar)[/li][li]11" NSR[/li][li]Aimpoint T1 (or similar)[/li][/ul]

If you haven’t guessed by the parts lists, the first build was aimed at being more of a precision based rifle with the ability to function in a more general combat/defense role as well. The second build is meant to reverse those roles, being more fit as a run of the mill combat/defensive firearm still having the potential to be fairly accurate if needed. What I am contemplating is one “Goldilocks” rifle using the components from the first build but substituting a Noveske 16" N4 Light Recce barrel w/ pinned Switchblock instead. Comparatively, that setup should be 6oz. lighter than the first build and 9oz. heavier than the second (I’m not comparing optic weight at this point because I view that as an interchangeable item). I would also expect it to be more durable than either of the original two builds, and require less maintenance than the first build.

In terms of accuracy, according to Molon’s Accuracy Evaluation the first build should shoot 0.8-1.0 MOA (10-shot groups with match ammo), the “Goldilocks” build should shoot 1.2-1.3 MOA, and my assumption is that the lightweight build would shoot around 1.5 MOA, but given the shorter barrel length velocity will be slightly reduced. The maximum distance I foresee shooting with the first build would be around 600 meters. Doing the calculations with the worst 10-shot extreme spreads measured by Molon, that equates to a theoretical 6.7" group at 600m for the first build and a theoretical 8.6" group at 600m for the second (assuming a capable shooter and ideal conditions). That difference of 1.9" becomes even more minute when taking in to account that it will yield a difference of only 0.95" off center and the fact that maximum magnification will only be 6x.

My questions for you experienced shooters:
[ol]
[li]Would you notice a 9oz. difference in weight along the length of the barrel, and would you consider it significant? (I realize this isn’t quite apples to apples, since the lightest build has a shorter barrel, but bear with me.)[/li][li]Would you notice a 0.3MOA difference in accuracy under ideal conditions at distances out to 600 meters, and would you consider it significant?[/li][li]Given your prior experience, which rifle would you consider the most desirable and why?[/li][/ol]

Thank you for taking the time to read and respond.

2

1.) Yes, but it wouldn’t bother me.

2.) Not really.

I would prefer a carbine length gas barrel with a heavy profile, if you’re gonna build a carbine. Especially if you run an A5.

3

I would go with a mid length 14.5 with a pinned muzzle break of your choice. Then pick up the optics of your choice with good QD mounts so you could do long range and short range work.

Also go with a 13 inch NSR. Just because it looks cooler lol.

4

Solid questions.

  1. Yes, but I would consider it insignificant.
  2. Negative.
  3. For an all-around workhouse, I like a 16" mid-length. A 14.5" doesn’t offer any real advantages, and if I were to go down the SBR route, I would want a 300 Build. If I were in your boat, I would build a solid, general purpose 16", and in lieu of the secondary weapon, I’d go for either a variable powered optic, and a RDS, being purpose dependent.

During the panic, I unloaded a lot of extraneous hardware, and simplified my setups to a common standard.

It is my opinion, and that’s what works for me, and for me only, that I am best served by a single carbine set up for 0-300m, and having various support gear and optics, depending on my useage.

My philosophy has been one of simplification. I look at the weapon itself as vanilla ice cream, and add tertiary equipment (sprinkles and hot fudge) to taste.

YMMV

5

Like others have said:

  1. Side-by-side, you would be able to tell the difference in weight, but it is of little consequence.
  2. Under ideal conditions at 600 meters, yes you would be able to measure a 0.3 MOA difference. However, most rarely shoot under ideal conditions and the practical difference will be negligible.
  3. I, and many others, configure our rifles for specific a specific purpose. But, in general, a good “capable of most things” rifle I consider to be a 16" mid-lenth gas system. This gives you the most flexibility out there. Good accuracy, yet still short enough for most confined space work a civilian will likely encounter. (Marines have been clearing houses with 20" barrels for years.) And you don’t have the inconvenience of a pinned muzzle device if you decide to change your handguards.

One question for you. Why the Switchblock? Do you plan on suppressing the rifle at some point? It is a solid piece of gear, but not really necessary. Just curious.

6

Myself, I don’t see enough difference between the two proposed configurations to justify two separate rifles. Given my experience, I would build the simplest 16 inch carbine that is as light and accurate as practical, keeping a couple of things in mind-

-Running an AR hard can take the fine edge off it’s accuracy. The increased heat an AR will subjected to in a carbine class, will accelerate throat erosion. It will be small amount but it will be there nonetheless

-An AR built as a general purpose carbine will be carried and handled more. Light weight and fast handling rules here. 9 oz is a half pound and I know I immediately notice weight savings as little as 4 oz and appreciate even smaller weight savings over time. However, it’s best to get the lightest components that fit the mission rather than get the lightest components possible. To me, that means using a lighter weight profile barrel instead of an HBar profile barel for a GP carbine

-1-6x optic is at the lower end of the magnification scale. For field applications, such a hog hunting, coyote calling, use on medium game or ringing steel, the difference between .5 and 1.5 MOA isn’t great enough to be usable. If we’re talking about prairiedogs or very precise shooting, then it would be and you should be using a scope in the 3-15x range and maybe a barrel length of about 20" or more

I think what I’d do in your shoes is build a GP carbine first, with a good quality but not overly expensive lighterweight 16 inch stainless steel barrel with the flat bowed version of the SSA trigger and shoot it. I’d get both optics you’re talking about and swap them back and forth as needed and see how everything performs. The worst that could happen is that you learn to shoot better and in doing so, uncover the shortcomings of the rifle that will let you build a second rifle or upper that’s better suited as an SPR. It’s also possible that you discover your GP carbine works well enough as is or only needs a bit of tweaking

7

As a basic response to your questions:

  1. A half a pound is noticeable but not significant. The difference between a RDS and a variable can give you this kind of variance.
  2. If you are shooting a match for groups, then yes, you’ll see it on paper. However, over 600 meters variable wind gusts can throw you off more than .3 MOA.
  3. If this is your first AR I’d go with a 16" Noveske mid-length (switchblock if a suppressor is in your future), 11" plus handguard and the Aimpoint T1. 14.5" barrels are nice but, unless you are going to SBR it I’d stay away from pinned muzzle devices. Chances are you will want to change something in the future and a pinned MD just gets in the way. If this will be used as a SD/HD weapon the Aimpoint is the clear winner IMO.
    If this is just for range fun and, you’re going to limit yourself to just one AR and, have regular access to 600 meters then by all means get the 1x6 variable.

You can always:

Have both optics with QD mounts and switch them out on a single upper.
Or, have one lower, build two complete uppers with different optics, barrel lengths / types.

8

I’d go with a good GP carbine first. A Noveske N4 barrel will be accurate and not terribly heavy. Then get a red dot of your choosing.

Next build up a dedicated long range rig.

9

1 - You would notice it, but it would rank low on priority.
2 - probably - significance depends on use
3 - If it were me, I would build the 2nd rifle with a 13" nsr and a pinned gas block - not switchblock as I have no use for it. How often are you going to shoot at 600yds and at what targets? How good are you at long range shooting right now? The 2nd rifle will be more than accurate enough for most uses. I would then buy both the scope and aimpoint on return-zero qd mounts. I would NOT build the precision rig until/if you decide it would really make a difference for you. Just my $.02.

If you decide you want 2 rifles you can always do it for the same price down the road, but Id definitely build the GPCarbine first.

10

More info please. I was not aware that there were mounts available that allowed you to take an optic off a rifle and reattach to keep your same zero.

11

http://www.laruetactical.com

http://www.bobroengineering.com

http://www.americandefensemanufacturing.com

http://gdiengineering.com

All will return to zero(or pretty damned close.) I haven’t had the greatest experiences with ADM based on issues unrelated to their RTZ(though many people love them,) but Larue, GDI, and Bobro are excellent excellent mounts in my experience.

12

My QD Bobra mount has ALWAYS returned to Zero when remounted.

Bobro is the cats pajamas.

13

The largest practical difference is in the optics.
Pick whatever shivers your timbers and choose the optic based on application.
I can get more done with a decent gun and good sighting capabilities than with a great gun and shitty aiming devices.

14

What optic would be your first choice?

15

Depends on application focus.

HD/SBR: T1/EXPS
GP: 1-4x/1-6x
DM/Dual Role: 1-8x or 2.5-10x with Mini RDS
Practical Precision: 3-18x

Sent from my VS980 4G using Tapatalk

16

Roger that. I am still using an Aimpoint ML2 for contact distance out to 300 meters. I guess I am farther behind the times than I thought.

17

That’s still a wholly acceptable optic. I wouldn’t seek one out, but I wouldn’t throw one away either.

Sent from my VS980 4G using Tapatalk

18

No need for the fixed 3x or 4x then?

19

Very good recommendations. It would be nice if he would indicate what his end use(s) is going to be.

20

For me, no.
I go through cycles with ACOGs where I forget how much I hate them, get one, use it for a while, sell it, and repeat the cycle. They can be ok for a few specific tasks, but generally lack real flexibility.
If I was going for a lightweight carbine that would primarily be used at 50 to 400 meters, in daylight, that I wanted to be battery-free; I would probably consider one of the 3x ACOGs again, as they are about 1/2 the price of a sort-of equivalent heavy-duty 1-4/1-6. The only acceptable reticles are the crosshair and the horseshoe-dot.
My only current ACOG is a TA01 with a piggybacked RMR, which I own only because a customer user-group is similarly outfitted (bought prior to my input and unable to change for another couple of years).