Rifle Scopes Co-witnessing red dots

[jonny pankau]

Hey guys, I was hoping you could provide a little direction to me for the best way to go. Backstory: I currently have an AR-15 with a TA31 ACOG on it. It is a great scope, but I am trying to sell it to free up some funds for something else. The direction I am trying to go now, is to find a good red dot that can co-witness with my Magpul Gen 2 BUIS. So my concerns are:
Is 1/3 co-witness more useful than absolute?
Does something like a Fastfire 3 have too small of a sight window?
What is a good red dot with a good price point that I can co-witness with?
Is co-witnessing even worth the trouble?

I know it's a lot, but any advice would be appreciated. Thanks!

 

[Papa Zero Three]

You need to provide some more info, like your budget for the red dot optic for starters. On the low end of the price range but still of good quality ,a few good optics would be the TRS-25 and the SPARC and price goes up from there.

As for 1/3 vs absolute, IMO it's personal preference as you can argue pros and cons for each. Personally, I run absolute, it's just easy and makes more sense to me. One of the reasons I like it is that I can take an optic off and put it back on and compare it to the irons to see if its moved at all. I've even used absolute witness of a known zero'd optic to "hillbilly zero" a second optic. I placed an eotech in front of my zero'd ACOG and adjusted the eotech dot to the ACOG and then removed the ACOG and confirmed zero of the eotech. I use the same method for zeroing my PEQ and reconfirming it if I've taken it off and am putting it back on. But this is my preference and what works for me, others may have a differing view. The other thing to keep in mind is if you have fixed or folding irons, height of your optics, your personal comfort/neck strain,etc may dictate which you choose or find works best for you.

 

[jonny pankau]

I appreciate the tips, my sights are folding and I was hoping to spend around $300 or less.

 

[Papa Zero Three]

OK, then just off of the top of my head in no specific order and by no means all of them:

TRS-25
SPARC
Strikefire
Aimpoint PRO
Burris fastfire III

 

[ajwcotton]

I personally have not found any of the micro red dots to be robust enough for carbine use, they just get banged around too much. I have broken two.
If weight is a concern then the aimpoint t/h1 are my recomendation, I know it is more than you want to spend but is the only real way to get a rugged optic into a small package. The downside of them is that the window is small and requires you to have at least a semi good shooting position to be able to pick up the dot.

Of the stuff in your price range I would go for an aimpoint pro, I honestly can't tell the difference between that and the older comp series and it is a couple hundred less. It has a bigger window so it is more forgiving from awkward positions than the micro and still has very good battery life. I prefer to mount them in a foward cantilever mount to I can run a magnifier or pvs 14 in between the optic and the rear sight.

As to the cowitness, I generally run lower 1/3 because I run an ir laser and it gets the sight up a little higher so I can have a little more FOV in the bottom of the window. I also like lower 1/3 for guns that have fixed sights so that I can see over the sights not through them, I have an entry gun that I set up with fixed sights so that it is always good to go kind of an emergency situation type gun. You can still use the sights to zero on lower 1/3 also the dot moves inside the window since it is a paralax free optic bullet impact is wherever the dot is so using it to zero is not an issue. You said you have folding sights that will be folded so absolute is probably fine for your application, I just think lower 1/3 is a little more versitile.
Anyway just my .02

 

[snowdog650]

Spend the extra $$ to get an Aimpoint PRO. You won't regret it. When on sale, they can be found for $365.

 

[scudzuki]

Absolute co-witness for folding BUIS, lower third co-witness for fixed sights or folding rear with fixed FSB.

The Bushnell TRS-25 with the mid-height UTG riser (which is surprisingly well made and robust) is close to absolute co-witness and 9/10 the functionality of an Aimpoint; it does not have the incredible battery life (courtesy of Aimpoint ACET), the incredible top end brightness (which I can't see ever using unless I'm taking pot shots at the sun) or the battle proven toughness, but myself and many others have run them for years on weapons from 10-22s to 12 gauge shotguns without failures.

That said, I have 2 Aimpoint Comp M4s that I'll likely never sell, they were a lifetime investment and worth the money spent (like an Aimpoint PRO could be for you if you can swing it).

Joe

 

[shovelstrokeed]

+1 on the Comp M4. The one atop my KAC SR-15 is never leaving the gun. It replaces a Trijicon Accupoint 1-4 with a gold spear reticle and, with the 2 moa dot has no problem reproducing the 100 yard groups and is effective on steel out to 300 with no problems for me. Also much faster to pick up targets shooting with both eyes open than the scope was as field of view is no longer limited. If gun is on shoulder and cheek is on stock, the bullet goes where the dot is. I'll be switching to a 20" Kreiger 1:7 upper so I can reach out a little further and that will probably get a variable optic for use on critters and longer range steel.

I have 2 of the Bushy TR-25s on my M&P 15-22 and 10-22 and they have proven reliable and repeatable. For the price, they are an outstanding buy. Only the M&P provides co-witness and it is spot on with the Magpul sights on that M&P. I rarely flip them up as it is pretty much for plinking but they are there if my batteries do go out. A danger since I got the Comp M4 as I don't worry about turning it off, like you have to with the Bushnells.

 

[hewlett260]

Not meaning to hi-jack but how does the Sparc compare to the Strikefire

 

[Mike_Honcho]

OP - start watching RiverOfGuns.com - just type Aimpoint in the search box. Pros and older 'M' models routinely show up for $300 - $350. Also, while FUGLY, the QRP mount is cheap and very serviceable; and depending on the use of the QRP spacer the user can decide on lower 1/3 or absolute.

RE: lower 1/3 or absolute - all personal preference. I like absolute.

 

[rayrevolver]

Is 1/3 co-witness more useful than absolute?

- My opinion is yes. Better sight picture.

Does something like a Fastfire 3 have too small of a sight window?

- Too small, no. I recently ran a Trijicon RMR as a primary optic on an AR-15 in a match. It worked great, no issues. It is a very light setup. SHTF optic for me is an Aimpoint Micro.

What is a good red dot with a good price point that I can co-witness with?

- They all will co-witness. Save us for the big three if you can (Buy once, cry once). $300 should get you something used in an Aimpoint. Maybe Trijicon RMR or EoTech.

Is co-witnessing even worth the trouble?

- Yes. What trouble are you talking about? Once the irons are zero'd, you can always just move the red dot to the top of your front sight. I would always re-check, but this method works fine.

 

[DaNooB]

TRS-25 is great for the money, I have tortured mine, not on purpose but it has taking a beating and still works just fine. Works great on my Vepr 12.

 

[Strykervet]

I always used 100% co-witness on the EOTech with KAC rear flips and fixed fronts. Never thought anything about it one way or another as the irons are simply a backup to me. I never used 'em together, but looking through the peep it looked a lot like a red lollipop.

But when I got NODs, I got the Larue EOTech mount and the Larue PVS-14 mount (both are required to line up right). This setup provides a 1/3rd bottom co-witness, and truth be told, if you run 'em together, it's not too bad if you're like me and don't like the dot superimposed over the tip of the iron. The dot rests above the iron with the iron inside the 60MOA circle. I'm okay with that.

In addition, a 1/3rd lower iron in the co-witness is ideal if you are using NODs affixed to the rifle behind a reflex sight, and fixed front iron sights. It allows for a much better sight picture when looking through the PVS-14 if the front iron isn't in the way, particularly at 1x.

So I guess it depends. How you plan to use it, how you prefer it to look, etc. But I find too much going on with the sight picture is problematic. That's why I tend to save the irons simply as backups. All my AR's have 'em, same 600m KAC flips, and they're zeroed and worked with for the most part, but they're only intended to be used if the scope fails at an inopportune time.

I also find that co-witnessing any sight to a reflex works best with the large window provided by the EOTech. It's just ideal for it IMO. I was always inclined to remove the Aimpoint if it failed (and batteries 12 years ago were problematic in M63's) because it didn't have a very wide FOV comparatively. As for 1/3rd vs. 100%, that's up to the shooter really, though *I* do find it more handy if running simultaneously, particularly with fixed front and a PVS-14.