I have two AR's, both with 16" barrels.  One has a fixed handle - the other removable, so I guess I want to set this up for carry handle mounting and have the iron sights available as well.

I plan on using 55 grain commercial ammo and would like a bullet drop compensator as well.  

My eyes aren't what they used to be.

Which ACOG/Compact ACOG  model do you recommend?  Which reticle?  Shooting paper from 50 - 300 yards.  

Any other mounting information/tips?

Best places to pick up a bargain on one of these?

TIA

Not an expert (have only had the TA31 for 30 hours 33 minutes [;)], however, for what it is worth my take is:

If you are shooting paper at 50 yards plus, then the BAC feature is of limited (no?) use for your application.  However, if you ever need to shoot at distances from your muzzle outwards then the BAC feature works very well ...

If you maxium range is 300 yards then the bullet drop feature is of very limited use (check out the thread on using various ACOGs in various mouts with various bullet weights .. which is pined on the top half dozen discussions).

With this said, I would look very carefully at the TA01 or TA11 with cross hairs or even a good variable scope.  Other option for the ACOG could be the TA31f (wrong BDC but at 300 yards no big deal).

Having tried the TA31 on the carry handle, would / did mount on the flat top (which the BAC feature you can get by with no iron sights ... unless the ACOG fails or is covered with mud / snow ... both which can be addressed with BUIS and ARMs mounts)

Regards
John

Thanks, fellas...

Any of these models made specifically for a 16" barrel - the ones I see all specify 20" or nothing at all?

TIA

All ACOGs with 5.56mm BDCs are designed for either 14.5" barrels and flattop or 20" barrels and carry handle (not including some special manufacture versions for JP Rifles).

For a 16" carry-handle mounted ACOG shooting 55gr M193, the difference between your point of impact and the 20" BDC will be less than the width of a crosshair at all ranges.

However, you can match the trajectory on the BDC closely just by adjusting your initial sight-in process. Check out the "Big ACOG BDC Chart" tacked in this forum for more details on that.



If you are shooting 50-300yds, a BDC doesn't really do you much good. The Compact ACOG will sit better in the handle than a full size and will cost less and weigh less.

If paper punching is your primary goal, I'd look at a red crosshair reticle.

The only consideration with a compact ACOG will be that in a carry handle mount, it will mount more forward than a full-size ACOG. So keep that in mind when comparing eye-relief measurements - even though the 4x32 ACOG and 3x24 Compact have the same eye relief listed, the Compact will be mounted further forward and you'll be pushing the limits of usable eye relief in a carry handle unless you drill another hole in it.

CSGunWorks - the TA01NSN is for a 14.5" barrel. Trijicon's website is wrong on that.

Thanks, Kelly - you sure know this stuff...

If I decide to dedicate a compact to a flattop - how would you mount it?

Appreciate the tips...

Well, you basically have several options. You can go with the special ring mount, you can use the TA60 flattop adapter (which will put it at the right height), or you can use it with the ARMS #19S throw-lever mount (quick removal; but designed for a full-size ACOG, so like the carry handle mount, the compact will sit lower). Some people also use the compact and #19S combination on top of an ARMS #38 to get more height but retain the quick detach ability.

I've only used compacts with the TA60 flattop mount and carry handle mount, so you'll have to ask around here about the others.

Making the question in your topic more specific will draw more replies from people who can help you better than I can with compacts.

Because the TA01NSN was design for the SOCOM M4 which has a 14.5" barrel.  

Not 100% positive, but the TA31-F is calibrate for the 55 gr @ 3250 out of a 20" barreled flattop.

To be fair, it is an educated guess; but here is what it is based on:

The NSN on the TA01NSN is because it was designed for the SOPMOD project - which is based around an M4 with a 14.5" barrel.

Knowing Trijicon's website is often wrong is based on past experience where they had the eye relief values on the TA31 and TA11 switched for almost 2 years. I also deal occasionally with Trijicon personnel and while they are a good group - they do seem to occasionally put out contradictory info on their products.

However, it is pretty much a pointless disagreement. At 300yds the difference in point of aim/point of impact between a 14.5" barreled flattop firing M855 and a similar 16" barrel would be 0.2". At 600yds, the difference is about an inch.

Short of locking a 16" flattop in a vise and firing M855 at a target 600yds distant in an environmentally controlled condition, we are unlikely to get a decisive answer; but my bet is on Trijicon's promotional material being wrong.



According to Trijicon, all the Fs are supposed to use the same BDC as the NSN. However, with the USMC adopting the scope for general use that may change to a 62gr 20" flattop. Who knows?

Nothing technical here. I have a TA01 on my 16" Hbar flat top using a #19 Acog. I zeroed it at 100yds with M193. I've shot it with various 55 gr ball and M855 out to 400. I was shooting at 12"x12" steel plates. I held center mass at all ranges and used the hash marks on the scope. I was geting hits at all ranges regardless of ammo type.

Mark

Regarding mounting, I'm still thrillin' with my set-up of a removable carry handle and a TA31 mounted to it.  I have both the iron sights and the ACOG sights instantly available.  The one caveat would be it's imperitive to remeber to hold 4" high when engaging targets at CQB range because of the difference in height between the ACOG's reticle and the rifle's bore.