EOTech Rifle Optics on the Benelli M4

[DC DOG]

Hi All:

Came back to this forum to update an old post, but figured I’d share something new as well. Lots of posts on optics for the M4, so I’m posting what I did with mine when I got a little “crazy,” (LOL).

Originally, I purchased EOTech optics, the EOTech EXPS3-0 (holographic sight) and EOTech G33STS (3X magnifier) to mount on a Fulton Armory M14 custom build (300 yard intended range, chambered in 6.5 CM). Then COVID-19 happened, and Fulton supply chain stretched to 8 months or more. I instead went with a Cadex Defense R7 Sheepdog bolt action (also 6.5 CM) with a Vortex Razor HD Gen II 4.5-27x56 FFP and RRS rail set. It’s a tack driver out to 500+ yards (easy) and I love it. With the tuned muzzle brake, a 10 year old kid can shoot this rifle and get amazing results.

I kept the EOTech gear because I got great pricing (shout out to EuroOptics) and because I still want to get that M14. Then one day I was working on my Benelli M4 and just happened to notice the EOTech optics and said, “what the heck!” So, I mounted them. Now, I’m NOT a fan of optics on a shotgun, especially for defense, but I had the time and gear so I did it anyway. The EOTech optics are VERY high profile, so there’s no “through the iron sights” alignment. It turns out that’s a GOOD thing.

To align optics sighting, I started with an in-the-bore laser shot shell at an outdoor range. I tuned the holographic sight at 20 yards first (precisely) then expanded to 50 yards (using slugs) by adjustment shooting. I then added the 3X magnifier and sight tuned precisely out to 100 yards (again using slugs) by adjustment shooting. Probably used 50 shells total to get what I wanted, and locked everything in.

The EOTech holographic sight has an outer ring and a centered point. Using it on a rifle, the point is sighted at the intended range, with measured “drops” below it. Using it on a shotgun, my sighting was 100 yards (point) and 50 yards (ring), specifically for two shot shells: the Hornady SST slug (2,000 FPS), and the Hornady Heavy Magnum “Coyote” BB (1,300 FPS). Without violating forum rules, let’s just say these shot shells are “very effective” for their intended purposes.

I got everything fixed and loaded up the good stuff. WOW. Just, wow. Even though the SST slug is a “blast” to shoot, I was getting 3 inch groupings at 50 yards (standing) using the 3X magnifier. The magnifier flips up and down, so you can use just the holographic sight or both. At 25 yards using the BB shells (also standing), I had about 12 inches of spread, mostly centered at 6 inches, using just the holographic sight. I’ve seen people call it “the donut of death,” and I can attest to that name: if your target is in that ring and you can see it, regardless of how you are holding or sighting the gun, THAT’S WHERE THE ROUND GOES. My friends laughed at me when I told them what I fixed up. Until they tried it at the range…

So, am I trying to “sell you” on EOTech rifle sights for a shotgun? NO, absolutely not. I did this just for fun to see how it worked. The mount profile is ridiculously high, LOL. Practically, and for defensive use, I don’t use optics on a shotgun, especially the Benelli M4. Hope you enjoyed this read…

[CharlesAFerg]

This is a great post, because it gives me a chance to share my experience with these on my M4. I have a 11715, with a collapsing stock, and an eotech that sits slightly lower. (XPS vs the EXPS shown here) I've found that Eotechs work really well in a few specific situations - when you wear armor or just want a shorter length of pull. As you said, the sight sits really high (too high, especially the EXPS) when used from the fully extended stock length, similar to your fixed stock. However, due to the way that the stock extends at an angle, if you only extend the stock to a notch or two back, the optic sits just right. So if I could make a recommendation to anyone looking to reproduce a similar setup, buy the XPS because the added height with the EXPS can make or break it's usability for you.

Here are some photos for reference. Notice how the further the stock is extended, the lower your cheek will be in relation to the optic. Sure, it's great for the irons, but the Eotech sits higher. Originally I wanted to mount a t2 to a fancy lower 1/3rd co-witness mount, but then I wouldn't be able to shoulder it with the stock in a very short position and still have a perfect sight picture.

Anyway, I hope this someone in the future.

 

[NooYawka]

I have a Holosun 507 pistol optic on my M4. It's on a super-low Scalarworks Sync plate so I can actually cowitness with the irons. At 25yds, even with sub-par ammo, I can get three slugs into a 6" circle or smaller. I've put probably 5k rounds through the gun in this configuration and I love it.

[Ronbo77]

Thank you. These are the most useful posts on this topic I have found. I mounted my XPS to my new M4 and I'm using a Mesa Tactical adjustable cheek riser stock. Everything lines up great--can't wait to shoot it. It is a bit bulky but when you start with a 9 pound shotgun, everything is relative, I suppose.  Ronbo

[Ronbo77]

Almost finished. Just need to add a polished/extended shell carrier. 

[Ronbo77]

Any suggestions for a hand stop on the fore end?