Which ACOG for an M4? Are USGI Acogs more durable? BUIS with an ACOG?

Tactical Gear Optics & Mounts
1

How long is the tritium good in an ACOG? Do they rebuild them when it runs out? Can I run a back up iron sight that flips up behind my ACOG?

Can I use the same Acog on a 16 and 14.5 inch M4? I want to run it on my colt 6920 or 6921. I want to use it for 0-500 meters point of aim and out to 700-800 point of target.

Are USGI ACOG’s tougher than the standard ones?

What color inserts should I go with and why?

My problem with the USMC issue one is that there are no back up irons on top and CQB is sort of hard. The guy that is training me knows how to use the USMC issue ACOG. Would he be able to teach me as well on one that has an iron sight on top?

http://www.trijicon.com/user/parts/products1.cfm?PartID=481&back_row=4&categoryID=3

http://www.trijicon.com/user/parts/products1.cfm?PartID=142&back_row=4&categoryID=3

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http://www.trijicon.com/user/parts/products1.cfm?PartID=142&back_row=4&categoryID=3

I like this one but is it as good as the USMC issued m4 acog? I noticed that the sides are not as wide.

3

The tritium in an ACOG is guaranteed for different lengths of time depending on what type of ACOG and what color the tritium insert is. If you click on the links posted above, to the right of the picture of the particular ACOGs are a few more links and one is for “Warranty Info”. Click on that one and determine which criteria applies to your particular ACOG and you’ll be able to determine how long the warranty is good for. And yes, they will replace the tritium if it fails within the warranty period. Personally I like this one (there are a few others similar to it) because it has the RMR attached for CQB. It is however the most expensive 4X model they offer.

http://www.trijicon.com/user/parts/products1.cfm?PartID=757&back_row=4&categoryID=3

4

Yes. If you get one, invest in a LaRue or similar throw-arm mount so that it makes sense to but a rear BUIS behind the thing. The stock TA51 mounts are okay, but are a PITA to get off in anything resembling a quick fashion.

Yes, but you will have slight variations on your POA, as an M4 RCO is designed specifically for a 14.5" barrel, 1-in-7" twist and the M855 round.

It would make no $$$ sense for Trijicon to tool a manufacturing line to make the same optic in a different robustness level. No, there’s no difference.

Whichever one your eye picks up the fastest, if speed is a primary concern. Only you can decide that. Scientifically, green is the color your eye picks up fastest, and that applies to about 90% of the population, with red and amber falling behind it in regard to what the human population sees better in the real (outside the laboratory) world.

The problem lies not in the lack of irons on the optic, it lies in lack of confidence with the optic and shooting at close ranges. Those things are a little silly, and you lose out on the fiber-optic reticle with that model. The ACOG does just fine, 50m and in, but you will have to train for that. I taught 147 Marines about that aspect just 2 days ago using occluded-optic exercises; it’s not really that tough to do.

A TA11 or TA33 would likely be a better choice, if the close-up stuff is a greater need/want than the long range aspect. The eye relief on either of those is nearly a whole inch greater and is more forgiving, and the respective 3.5x and 3x magnification aids in faster acquisition for the closer ranges compared to 4x.

5

I want that model…pricy though.

6

Just FYI, that was the SOPMOD ACOG.

7

I used to be a Supervisor in the Trijicon ACOG Department. Now I’m a Military and Law Enforcement Tactical Gear retailer. I can answer all of the questions you might have.

How long is the tritium good in an ACOG? Do they rebuild them when it runs out? Can I run a back up iron sight that flips up behind my ACOG?
I know that the different colors of tritium lamps have different lifespans (but all of them are at least 5 years, and some go out past 10 years). It would be best to email Trijicon at info@trijicon.com to ask them what lamp is in the model you like.

You can get the lamp replaced when it runs out. You simply send it back and they’ll open the scope and replace the lamp for you (there is a cost, and you can’t replace the lamp yourself).

Can I use the same Acog on a 16 and 14.5 inch M4? I want to run it on my colt 6920 or 6921. I want to use it for 0-500 meters point of aim and out to 700-800 point of target.
There are 3 different barrel lengths that Trijicon ACOG scopes are made to.
TA31RCO-M4 = 14.5" barrel
TA31F = 16" barrel
TA31RCO-A4 = 20" barrel
TA31RCO-M150 = 20" barrel

  • Note: Unless it specifically says a barrel length in the description, the scopes are generally calibrated with 16" barrels.

** With that in mind, you can go UP or DOWN one barrel length and still be OK. So if you got a TA31RCO-M4 (14.5" barrel) you can go UP one to a 16" barrel but not UP TWO to a 20" barrel.

Are USGI ACOG’s tougher than the standard ones?
That’s a common misconception that only the “military models” are MILSPEC tough. The TA01 uses the same tough housing, lenses, and internal components as the TA31F. For Trijicon it doesn’t make sense to make any “non-military” ACOG models because they’d like to sell them ALL to the US Military. So no matter which one you choose, it will be MILSPEC tough.

What color inserts should I go with and why?
I think you’re talking about the Reticle Color here. Reticle color is generally a “user preference” issue. What I like to say is “You’re not going to find much RED in your target environment unless you’re shooting at stop signs, shooting at things that are on fire, or shooting at things that are bleeding. In that case you can probably stop shooting…lol”. The other colors are OK, but we’re not big fans of the green because there is too much outside that is green (the Trijicon green isn’t the same as grass green or tree green, but it’s close and might cause some target acquisition issues).

My problem with the USMC issue one is that there are no back up irons on top and CQB is sort of hard. The guy that is training me knows how to use the USMC issue ACOG. Would he be able to teach me as well on one that has an iron sight on top?
I have to say that the backup ironsights on the ACOG scopes are a bit overrated. They are not adjustable, so you can’t “zero” them. If you’re looking for backup ironsight capability it’s better to go with a separate low profile flip-up ironsight like the ARMS 40L. The ARMS 40L will fit nicely under a TA01 series (TA01, TA01NSN, TA01NSN-RMR, etc) or TA31 series (TA31, TA31F, TA31RCO-M4) scope.

If you have any other questions don’t hesitate to ask. If you’d like to email us just use the contact email in our profile. You can also see our website address in our profile.

8

I just got a $414 quote from Trijicon to have this done on my 7 year old TA11E. :eek:

9

Replacing the tritium lamp is a fairly expensive process. Its just like replacing an engine or transmission on a car. It’s not as simple as opening up the scope and dropping a new lamp in. A brand new fiber optic assembly has to be made with a new lamp (the old fiber optic assembly can’t be used again). Also the internal prism assembly needs work and prep before the new fiber optic assembly can be installed. After this is completed, the scope needs to be reassembled, refilled with nitrogen, and then run through the quality assurance checks.

10

Not sure the RCO-150 is for the 20" barrel.

I looked through my new RCO 150 and at the bottom of the recticle it says “TA31RCO-M4”.

Although I’d use it on either rifle.

-Arbiter

11

Huh. The M150 should be for the 20" A4, that was the original intent of them buying the thing, for an organic (if ad-hoc) DM capability within the squad.

So, either they got both the A4 and M4 variants, like the Corps did (don’t think so, but I’ll check just to be sure), or yours isn’t actually an M150, but a no-shit TA31RCOM4. That indicator at 6 o’clock of the FOV definitely makes yours an M4 BDC.

If I may ask, did you buy it face-to-face or order it?

Using an ACOG tuned for a 20" barrel isn’t catastrophic, but one needs to practice at distances past 300m IOT know their holds; for 0-300 non-“precision” shots, there’s little functional difference.

12

I’ve been using a TA33G-H for about 8 months now and I don’t find it to be an issue at all.

I live in the mountains of VA (green everywhere) and I’ve yet to have the ret wash out on a green background. Various light and weather conditions as well as terrain… As far as I can tell you’d virtually have to be aiming at a green neon sign for it to be a problem.

After using all three (green,amber,red) in various optics… They all work well IMO. All in all I prefer the green… Followed closely by red and amber. I wouldn’t be upset if I was “stuck” with any particular color.

13

Arbiter has the right of it, the M150 is calibrated for M855 out of a 14.5" 1-in-7 barrel. NOT made for 20". That’s direct from Trijicon.

Still waiting on word as to what it’s supposed to read, but it occurred to me that if you have a TA31 with actual adjuster knobs (external, toolless, unlike the RCO, which takes a flat screwdriver or similar…), you definitely have an M150 variant. Which is still simply a modified TA31RCO-M4, so it wouldn’t surprise me that they’d leave the markings as they were.

14

I understand the cost as it is a detailed process to replace the tritium. One would think that if they figured out how to apply battery power to the Tri-Power offering, they could do the same with the ACOG’s.

15

With almost new ones on EE and places for less than $1000, it might be better to just relegate a degraded ACOG to a secondary weapon or fun gun and get a new ACOG for the primary… Nice new glass, new tritium and no scratches on the lenses…

It’s not as if the fiberoptics won’t power up the reticle in MOST SITUATIONS a secondary weapon would be used for…

Rmpl

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Concur, with practice I had no problems quickly acquiring the chevron and placing it on the appropriate POA to hit COM or the “T-box”. The EOTech on my personal rifle was of course faster at close range, but since I’m unlikely to be the number one man in the stack for an entry team anytime soon, the ACOG is plenty fast for my needs.

One question for our ACOG SMEs: When they replace the fiber optic, can they change the color as well? Looks like the color of the fiber optic is what causes the reticle to show up as red, green, etc. I’m strongly considering a TA31F but am intrigued by the green reticles. Mostly just curiosity though, since TBD7117’s post seems to indicate that the cost would be prohibitively expensive just to change the reticle color.

18

Yeah, all the tritium does is provide a light source. The FO provides the color and directs light to the reticle.

The cost mentioned above is for replacing tritium, so what it would be for a FO swap is another question. Might be less $$$, might not. Worth pinging Trijicon to find out.