Question about ACOGs

[d90king]

The answer to the question is yes, it is usable. I have run my NSN on my .308's with no issues and the holds are much closer than one would think. Eye relief on the NSN is a bigger issue using .308, than the BC is...

I'm running a 200yd zero on the 100 hash, it is very close all the way out to 500 with everything from 150gr - 175gr... I have run it on my MWS, SCAR 17 and OBR.

Keeping in mind that I have not used it to shoot groups but I have shot plenty of steel with it.

Is it ideal? No, I think you would be better served with a 1-4X, 1-6X or a 1-8X on a SCAR 17. I'd look at the new MK6 for the SCAR 17 (probably what I will be adding for mine)

[shootist~]

Yes - The trajectories at normal distances are not that much different and are potentially more affected by your local environmental conditions (DA = density altitude being the biggest) - compared to what DA might be used for the ACOG. Also the ACOG may be calibrated in meters and your known ranges might be in yards, so nothing is ever perfect anyway.

Set your zero using a mid-range (using that specific hash-mark). For example, 300 meters works well for a TA01NSN and minimizes the ammo's ballistic differences at 100, 200, 400 & 500. If you are then high by 1" at 100 yards and 3" or so low at 500 meters, will it really matter? Going from sea level to 5,000' will change things even more (at 500 meters, but not at 100).

Run some type of ballistic software - set various zeros (100 or 200 or my suggested 300 meters - or yards) - with 5.56 and your 7.62x51 inputs, and see if it meets your requirements. For practical purposes it will do fine out to 500 and certainly to 400.

FWIW, Surplus 7.62x51 in my SCAR 17 runs around 2,550 fps (a little more for Aussie '91 and a little less for S.A. '81). Using the BC (ballistic coefficient) for Hornady 150 gr FMJ @ .398 works pretty well for both.

M855 out of a 14.5" barrel will have a higher initial velocity, but it's offset somewhat by a lower BC.

But an optic with a ranging type reticle - Mils or MOA hash-marks, works too.

[shootist~]

Just my personal opinion, but I think a black scope & mount looks "correct" - if that matters, and possibly more so than adding more tan to the rifle.

Optic is a NF 2.5-10x32 with the ADM Delta mount. Switching to this (beefier and non cantilevered) mount made a noticeable improvement in my SCAR-17 groups. Related post in the "How Accurate is Your SCAR" thread:
https://www.m4carbine.net/showthread...=106843&page=4

[VIP3R 237]

I was thinking the exact same thing, ridiculous.

OP, get the correct Acog ceracoated.

Exactly this, Cerakote is a high quality firearm finish, much more durable than a rattle can job.

Plus with the many color options you can choose which of the 3 colors of the SCAR you want to match!

[The Rat]

Another problem you're going to run into is the short eye relief on a standard ACOG combined with the stouter recoil on a 7.62 platform.

I had a TA31 ACOG on an AR10-type platform for a while, and it was pretty hard to keep it from banging into my glasses with every shot.

[ptmccain]

Another problem you're going to run into is the short eye relief on a standard ACOG combined with the stouter recoil on a 7.62 platform.

I had a TA31 ACOG on an AR10-type platform for a while, and it was pretty hard to keep it from banging into my glasses with every shot.

Thanks for the great advice, guys. Really appreciate it.

[Jippo]

I run a .223 TA11 on my Heckler & Koch MR308 and it is an excellent optic for the rifle. It is much more forgiving than the 4x models regarding the eye-box and eye relief.

It being .223 makes absolutely no difference since the .308 may be fed anything from 123 grain to 185 grain bullets: they won't have matching trajectories anyway. Ballistic compensated reticles work for one specific muzzle velocity and bullet type only, roughly put. I have small plastic covered prints for my rounds I use which I can tape on the buttstock. I have a point blank range of 200m so if I am in a hurry I can always point & shoot, but on longer distances I can check the cheat notes and be sure of the correct hold over.

By varying zeroing distance I can get most rounds hitting the reticle ladders on even distances. I mean, I have shot torso sized targets with the same scope at distances of over 600yds with a 7.62x39! (zeroed @ 150m it will fully match the 500 hundred ladder at 300m, and closely match the 700 ladder at 400m and 800 ladder at 500m.) Compared to that .308 is easy.

[nimdabew]

The reason I ask is because I want to get a SCAR 17s in FDE, but Trijicon does not presently make an ACOG for .308 in FDE, but they do in 5.56.

... really?

[ptmccain]

I run a .223 TA11 on my Heckler & Koch MR308 and it is an excellent optic for the rifle. It is much more forgiving than the 4x models regarding the eye-box and eye relief.

It being .223 makes absolutely no difference since the .308 may be fed anything from 123 grain to 185 grain bullets: they won't have matching trajectories anyway. Ballistic compensated reticles work for one specific muzzle velocity and bullet type only, roughly put. I have small plastic covered prints for my rounds I use which I can tape on the buttstock. I have a point blank range of 200m so if I am in a hurry I can always point & shoot, but on longer distances I can check the cheat notes and be sure of the correct hold over.

By varying zeroing distance I can get most rounds hitting the reticle ladders on even distances. I mean, I have shot torso sized targets with the same scope at distances of over 600yds with a 7.62x39! (zeroed @ 150m it will fully match the 500 hundred ladder at 300m, and closely match the 700 ladder at 400m and 800 ladder at 500m.) Compared to that .308 is easy.

Thanks, appreciate it.