I have an Aimpoint Comp M4, and am thinking of getting a 3x magnifier with a flip to side mount for an all-around optic.  However, I have been having second thoughts and wondering if a 3x (or 4x) ACOG is more precise.  How precise/accurate is an M4 with a magnifier, as precise/accurate as a similarly magnified ACOG?

ACOG will have the bullet drop compensator so that will help with hold over at longer ranges.  I just sold my aimpoint to buy a ta33g-8 (3x30) which i actually picked up from UPS today.   I think it is a much better solution for longer ranges rather than an aimpoint + magnifier, that and it is a lot more compact and I think there is less to go wrong.  The prices are likely very similar as well.

 

I had both.  I sold my Aimpoint magnifier.  I now have rifles with T1s, M4s, and M3s.  I also have rifles with TA11F's.  

The ACOG is far, far, far superior than a RDS + magnifier.  No comparison.  For me, the 3X magnifier is a poor solution.  The eye relief, FOV, and optical quality is not near as good as the ACOG.  Most people also have some amount of astigmatism.  This makes the RDS look like a comet behind the magnifier.  

The ACOG is an awesome scope.  You will not be disappointed.

+1 for T-1's and TA11(x)'s

Thanks for the very useful reply.  I thought that the MOA might be huge with a magnifier and not give any precision on longer range shots.  Is this a problem too?  I suppose I could use an ACOG with a RDS mounted on top, but it seems you'd have to use an adjustable stock and adjust to either aim down the ACOG or the RDS.  With no adjustable cheekpiece, I just don't see how you can get aim down an RDS riding on a ACOG under stressful conditions.

3 guners will mount a 3x-9 on top of the rifle and a rds or jp irons canted off to one side.

The MOA of the dot on the aimpoint will not change under magnification.  The magnifier will magnify the dot and your target by the same amount so the relation of the dot size and target size will be the same. Does that make sense?

 

That does make sense, thanks.  I wonder about precision too.  If your target is a small plate at 300 yards, what gives the best chance of a hit, a 3x ACOG or a CompM4 with a 3x magnifier?  Do they even give the shooter an equal chance I wonder?

Unmagnified, at 300 yds, your M4 dot will be 6".  With the magnifier, the dot and the target will be magnified together.  So, no big deal.  But, the dot will be distorted unless your eyes are perfect.  

The ACOG will give you a better sight picture because the glass is clearer .  And if you use the chevron, you will have a smaller aiming point.

You're not trying to avoid being put in Open class, are you? Put both the ACOG and Aimpoint on flip mounts!



 

I have both, and they excel at what they were designed for. Aimpoint is better up close, and ACOG is better at medium range.
I've shot my Aimpoint/magnifier setup successfully out to 500 yards on silhouettes, but the ACOG is more precise and a better choice at those ranges.



As previously stated, the MOA size of the dot does not change when
magnified since both the dot and target are magnified.



That is why many people use an offset mount for the RDS––you keep your head in the same position and cant the rifle inward 45 degress so the RDS lines up your eye. Only downsides are that it doesn't work for support side shooting with the RDS, and it's not an ideal position of your RDS is your primary optic.



The ACOG/RDS setup is better if your rifle is mostly for medium range shooting with a little up close shooting, and the RDS/magnifier setup is better if your rifle is mostly for up close shooting with a little medium range shooting.
 



 

I'd echo the statement above, and add that the magnifier exists up primarily to increase target identification, as is the ACOG.  The speed of the Aimpoint below 100 yards for a typical sillhouette can't be argued.  Same can be said of the ACOG beyond 100 yards.  They're designed to increase your hit potential.  I'm in the camp of those who don't want two primary sights attached to their gun, for a few key reasons.  

The magnifier is there to supplement the RDS when required.  Of course you could say the same for an offset RDS over an ACOG - but again, you get into offset issues, head position, lag time in swapping optics under duress, etc.  Most of the time the 3X mag will remain disconnected and stuffed in your gear bag.  I only break it out on occasion.

I have astigmatism too, and that "comet" shape is definitely there.  But for what it's intended to do - the 3X is an awesome add to a general purpose carbine.  Is it better than a 1-4X or ACOG?  Depends how you value: weight, manual illumination, magnification, bullet drop, speed, precision, etc etc etc....

Get what you want - but make sure you want what you get!

At mid-range the RDS with 3X is usable, but inferior to the ACOG for the reasons quoted above.
However, for me, magnified optics such as the ACOG are unusable in CQB.
So, for me, carrying a single rifle and not knowing the situation I'll encounter, RDS with flip-up 3X is the best choice.

I tried both a T-1/3x on larue and a TA11 on my recent lightweight scout build.
The t-1/3x was obviously better up close and lighter (but a little bulkier IMO), but due to the clarity and FOV at distance, the ta11 won out.

My opinion is worth the paper its written on, but here it is.  The 3x is a great add on option for making farther or more precise shots at distance, but shouldn't be a primary system.

ACOG plus T1 on a Larue offset mount.  You can do everything you need to - CQB + distance.

What about a TR24 1-4 variable?

I understand that with training it can be learned, but offhand I could not get any kind of comfortable or repeatable cheek or chin rest with an offset T-1.

It's a compromise.



The TR24 doesn't have the Aimpoint's forgiving unlimited eye-relief or the ACOG's BDC, and it's heavier than both. It's good at close and medium ranges, but superior at neither.



 

Chapper, the Larue offset mount is not the one you mount on top of the scope.  You don't have to worry about cheekweld or mounting issues.

I didn't try the larue.  

To clarify, I tried the dd at every angle as well as direct mounting on all angles of a jp/vtac tube.

if i was to go two-at-once, then I'd get the top-of-the-acog mount.  at least then I'd have a chin-weld.

A C-More mounted offset on a JP/VTAC tube works much better.  Bigger window and all that.