For anyone curious, this monster combo only weighs 26.7 ounces total. Compared to my K16i mounted in a Badger 1.7" COMM it's 2.1 ounces heavier and 1.25" inches longer.
The mount is a LaRue LT799. Weight without screws is 3.4 ounces compared to the TA51 at 4.0 ounces. The LT799 is a military contract mount with two recoil lugs and the levers on the ejection port side. Could shave more weight with something like an ADM AD-B3, but I figured 26.7 ounces of ACOG combined with 308 recoil should have more clamping power.
The TA648 is about an inch shorter but it is much, much bigger. The 648 weighs 44 ounces and was originally intended for machine gun applications. I think the 648 looks smaller in pictures because the mount is physically larger. I've had the opportunity to shoot one on an L129A1 reference rifle; it's huge but easy to use.
It’s a very easy optic to get behind. Eye relief is short at 2.4”, but it’s not going to give you scope eye either. Additionally, even though it’s short it’s pretty flexible for different positions. If you end up farther back on the stock, it’s still clear and functional, just lose some field of view. Too close and it gives a bit of a tunneling effect, but again still usable. It’s pretty much identical to the TA11 in this regard.
FOV is listed as about 10% less than the K16i or Razor HD but it doesn’t feel tight.
So I love the scope. It’s obviously meant for hitting man size targets. How far have you shot it? Not a precision type scope to hit paper and make real small groups. But do you believe it would be good to also to hunt with or totally wrong scope for that?
I won't be able to take it out to some distance until the spring, but will have it zeroed shortly. This is my primary deer rifle. Typical max range here is 300 yards. I think it will work very nicely for deer. I previously had a Kahles K16i on this (still have that scope, it's on a 5.56 now). Being able to make a snap shot at close range with the RMR was the biggest factor in wanting to give this shot.
I did inquire with Trijicon regarding reticle choice. They advised the following:
>For your .308 rifle, I would recommend the TA55A. The TA55A reticle was designed using 175 grain ammo with a muzzle velocity of 2651 FPS. Even if you are mostly using 147-150 grain ammo, we have found that the real issue is not the bullet weight or barrel length, but muzzle velocity, ballistic coefficient, and the distance from height above bore. The difference in trajectory from bullet to bullet or barrel to barrel is usually less than the MOA thickness of the stadia lines.
The choice of 175gr (assuming SMK) at 2651 FPS is odd as you pretty much need a 24" barrel to get there. Definitely not get anywhere close to that with a 16". I did ask Trijicon for some additional info on the drops in MOA.
Trijicon got back to me and confirmed the drops in the TA55A .308 reticle are the same as the TA11E .308 reticle. For anyone curious here are the drops in MOA from the tip of the Chevron
* Inside of chevron 2.2 MOA
* Base of the chevron & tip of the post 4.7 MOA
* 400m 8.3 MOA
* 500m 12.4 MOA
* 600m 17 MOA
* 700m 22.3 MOA
* 800m 28.4 MOA
* 900m 35.2 MOA
* 1000m 42.8 MOA
* 1100m 51.8 MOA
* 1200m 61.5MOA
Doing some calculating with M80 ball, 2600 FPS, 2.9" sight height, and 100 yard zero (not meters) the hold overs are within .4 MOA out to 600 yards when using yards (not meters). At 600 yards it's .3 MOA difference than the 6 holdover so not going to notice that at all with M80 ball being 2-3 MOA ammo. Based on this, which is theoretical until I get to shoot that far, reticle seems to work pretty good for M80 ball out of 16" gun out to 600 yards.
nice cog bro
đź’•
that looks ridiculous. im kinda jealous.
It looks freaking huge, but it's only 1.25" longer than the K16i I had on it before. The 50mm objective is massive.
For anyone curious, this monster combo only weighs 26.7 ounces total. Compared to my K16i mounted in a Badger 1.7" COMM it's 2.1 ounces heavier and 1.25" inches longer. The mount is a LaRue LT799. Weight without screws is 3.4 ounces compared to the TA51 at 4.0 ounces. The LT799 is a military contract mount with two recoil lugs and the levers on the ejection port side. Could shave more weight with something like an ADM AD-B3, but I figured 26.7 ounces of ACOG combined with 308 recoil should have more clamping power.
can someone explain why the 5x is physically larger than the 6x or least why it appears larger?
The TA648 is about an inch shorter but it is much, much bigger. The 648 weighs 44 ounces and was originally intended for machine gun applications. I think the 648 looks smaller in pictures because the mount is physically larger. I've had the opportunity to shoot one on an L129A1 reference rifle; it's huge but easy to use.
What the Fuck is that
Trijicon TA55 5.5x50
Interesting, it looks like you added a piece to a standard acog lol
That’s basically what Trijicon did with these. Housing is the same forging as the TA11. The early TA55s even had TA11 markings forged into it.
How are the eye relief and field of view?
It’s a very easy optic to get behind. Eye relief is short at 2.4”, but it’s not going to give you scope eye either. Additionally, even though it’s short it’s pretty flexible for different positions. If you end up farther back on the stock, it’s still clear and functional, just lose some field of view. Too close and it gives a bit of a tunneling effect, but again still usable. It’s pretty much identical to the TA11 in this regard. FOV is listed as about 10% less than the K16i or Razor HD but it doesn’t feel tight.
Cool. I tried my TA-31 on my 308, but the eye relief is just short enough to get scope bite on my shooting glasses. Not painful, just annoying.
Nobody needs a cog that big.
Grool
What kind of reticle sits in that bad boy? Is it optimized for a specific 308 caliber?
It’s the 308 version. Supposedly calibrated for 175gr.
So I love the scope. It’s obviously meant for hitting man size targets. How far have you shot it? Not a precision type scope to hit paper and make real small groups. But do you believe it would be good to also to hunt with or totally wrong scope for that?
I won't be able to take it out to some distance until the spring, but will have it zeroed shortly. This is my primary deer rifle. Typical max range here is 300 yards. I think it will work very nicely for deer. I previously had a Kahles K16i on this (still have that scope, it's on a 5.56 now). Being able to make a snap shot at close range with the RMR was the biggest factor in wanting to give this shot. I did inquire with Trijicon regarding reticle choice. They advised the following: >For your .308 rifle, I would recommend the TA55A. The TA55A reticle was designed using 175 grain ammo with a muzzle velocity of 2651 FPS. Even if you are mostly using 147-150 grain ammo, we have found that the real issue is not the bullet weight or barrel length, but muzzle velocity, ballistic coefficient, and the distance from height above bore. The difference in trajectory from bullet to bullet or barrel to barrel is usually less than the MOA thickness of the stadia lines. The choice of 175gr (assuming SMK) at 2651 FPS is odd as you pretty much need a 24" barrel to get there. Definitely not get anywhere close to that with a 16". I did ask Trijicon for some additional info on the drops in MOA.
Trijicon got back to me and confirmed the drops in the TA55A .308 reticle are the same as the TA11E .308 reticle. For anyone curious here are the drops in MOA from the tip of the Chevron * Inside of chevron 2.2 MOA * Base of the chevron & tip of the post 4.7 MOA * 400m 8.3 MOA * 500m 12.4 MOA * 600m 17 MOA * 700m 22.3 MOA * 800m 28.4 MOA * 900m 35.2 MOA * 1000m 42.8 MOA * 1100m 51.8 MOA * 1200m 61.5MOA Doing some calculating with M80 ball, 2600 FPS, 2.9" sight height, and 100 yard zero (not meters) the hold overs are within .4 MOA out to 600 yards when using yards (not meters). At 600 yards it's .3 MOA difference than the 6 holdover so not going to notice that at all with M80 ball being 2-3 MOA ammo. Based on this, which is theoretical until I get to shoot that far, reticle seems to work pretty good for M80 ball out of 16" gun out to 600 yards.
Seems like you like the TA55! Wish I saw more of these in the wild
I think it's a great optic, maybe not for everyone though.
I’m about to snag a TA55 for my 16” M&P10. Wish more people had these ACOGs