Which ACOG to get?

[a1madrid]

So my next AR is gonna be a 12.5 inch barreled gun with a carbine length gas system. I’m pretty set on running an ACOG on it. If you go on Trijicon’s website there are tons of 4x options that claim to have the BDC for 5.56. I know that the model the military has used extensively on the M4 is specifically calibrated for the BDC out of a 14.5 inch barrel. Now looking at the ballistics out of a 12.5 inch barrel vs 14.5 inch barrel, there is some loss in velocity but it is not a HUGE loss. I have seen a decent amount of people running ACOGs on 12.5 setups but my question is which 4x option will matchup CLOSEST to 12.5 ballistics? I saw on a livestream Lucas from TREX arms was running an ACOG on a 12.5 and he said he was hitting steel at 400 easy with it, which is all I would expect the 12.5 to do. I’m assuming the model that will match up CLOSEST to the ballistics of the 12.5 is whichever model is calibrated for the bullet drop of a 5.56 out of a 14.5 barrel but I want to know which one specifically? And do they make that model with a green chevron or with any green options? I also was planning on running this gun suppressed full time so I’m assuming I will get some velocity back but not a whole lot. And the majority of the stuff I will be shooting and what my guns are zeroed with is 55 grain XM193. Thanks guys.


Sent from my iPhone using Tapatalk

[1168]

NSN version for 62gr should be pretty close, if you true it a little further out.

[a1madrid]

NSN version for 62gr should be pretty close, if you true it a little further out.

Also, the majority of the stuff I will be shooting is 55 grain XM193.


Sent from my iPhone using Tapatalk

[markm]

I just set up my 14.5 with a TA01NSN, and I'm running 69 gr RMR bullets hand loaded to about 2850 fps.

I was sure the load wouldn't keep up with the reticle, but the ammo is actually outpacing the reticle. I'm holding belt buckle on a 500 yard target to get close to center mass.

My COG and load would likely match up good with a 12.5. I bet XM193 tracks pretty good.

[bamashooter]

As you know, ACOG and all others are spec'd to a single round and whether people want to admit it or not, a specific barrel length. Just they way it is and can only be. With that said, extended distances aside and a willingness to accept a less than designed for result, you should be able to satisfy your desire for an optic with BDC; within reason. You should be able to get a disabling hit at under 400m / multiple quick hits <300m once you establish your primary zero.

[a1madrid]

As you know, ACOG and all others are spec'd to a single round and whether people want to admit it or not, a specific barrel length. Just they way it is and can only be. With that said, extended distances aside and a willingness to accept a less than designed for result, you should be able to satisfy your desire for an optic with BDC; within reason. You should be able to get a disabling hit at under 400m / multiple quick hits <300m once you establish your primary zero.

I’ve seen videos of people hitting steel out to even 500 yards with them on a 12.5. If it was still a combat effective reticle on a 12.5 out to 400 yards I would call that a success. But again I am not sure which 4x ACOG to go with. Whichever model is for the 14.5 I would assume would work best but I don’t know.


Sent from my iPhone using Tapatalk

[Pikey]

As you know, ACOG and all others are spec'd to a single round and whether people want to admit it or not, a specific barrel length. Just they way it is and can only be. With that said, extended distances aside and a willingness to accept a less than designed for result, you should be able to satisfy your desire for an optic with BDC; within reason. You should be able to get a disabling hit at under 400m / multiple quick hits <300m once you establish your primary zero.

I’ve used a 4X ACOG on a 7.62x39 AR with good results out to 400 yards with some success at 500 yards, prone off of a bipod. At 300 yards an 8” gong was easy just use the 400 yard line and hold a little high. The problem with bcd is that they will probably not be exact for anything. But if you shoot you can figure out the holds.

[308sako]

I have had 2 TAO1NSN'S for a decade or so, in that time I have found that if you take the time to match your munitions to the reticle... you have won the ballistic lottery.

[1168]

Also, the majority of the stuff I will be shooting is 55 grain XM193.


Sent from my iPhone using Tapatalk

If your main objective is just getting to 400, I think you’ll be fine with a version meant for 14.5” M855. XM193 from a 12.5” barrel isn’t too far off in velocity from M855 from a 14.5” gun, so it should work. Like MarkM, I shoot 68gr ammo to 500 or 600 using BDC reticles similar to the ACOG’s all the time. None of those reticles were designed for that ammo weight, and most weren’t even designed around my 14.5” or 12.5” barrels, but I do just fine.

Are you using Winchester, or Federal XM193? What target types?

[a1madrid]

If your main objective is just getting to 400, I think you’ll be fine with a version meant for 14.5” M855. XM193 from a 12.5” barrel isn’t too far off in velocity from M855 from a 14.5” gun, so it should work. Like MarkM, I shoot 68gr ammo to 500 or 600 using BDC reticles similar to the ACOG’s all the time. None of those reticles were designed for that ammo weight, and most weren’t even designed around my 14.5” or 12.5” barrels, but I do just fine.

Are you using Winchester, or Federal XM193? What target types?

The mix of my ammo stash right now is Hornady Frontier XM193, Federal American Eagle XM193, and I do have some of PMC’s XM855 load too. The majority of what I shoot and what I will buy in the future is XM193. Keep in mind I am also going to be running this gun suppressed a lot of the time too. So that will bring SOME (not a a lot but some) velocity back as well, narrowing the gap between 12.5 and 14.5 ballistics a little bit more.


Sent from my iPhone using Tapatalk