"Actual" Parallax-Free Red Dots?

[J Whisky]

CGNr's,

I'm doing research in an attempt to decide on my first RDS. I know topics like this must come up all the time but I'm hoping I can draw on some experience concerning a specific question I have about parallax.

All of the RDS' I'm looking at are advertised as "Parallax-Free" but a little extra digging has led me to learn that this is usually only the case outside of 25m or 50m but that parallax is present at closer ranges.

I'm looking to put this on an SBR so closer range accuracy is important to me.... I'm looking at shooting at various ranges inside of 100m primarily. Obviously I could co-witness with my mbus for really close range but I'd prefer to pick up an RDS that is truly and completely parallax free. Do these exist and if so which ones? I'm assuming the longer tube types may be the ones to look at? I like the micros but I have no issue with a longer tube if it means zero parallax at any range.

Weigh in please with your thoughts and experience!

 

[RyanMumbles]

Interesting, I will have to test for parallax further out. I have a holosun RDS and it appeared to have a parallax at ~ 8-10m. I had no idea range factored into it lol.

 

[Phat Eagle]

AFAIK EoTech and Aimpoint are as close to parallax-free as possible. An EoTech technician shared the following info about the 550 (and all EoTechs are pretty much the same):

"The sights do have parallax error of +/- 1.2 " or +/- 0.6" (1.2 " side to side). The sight is designed to be parallax free at long distance 100yds to infinity. At close range, there will be a parallax error equaling to the width of the window which is 33mm or 1.3". A perfectly aligned sight will have parallax error of 1.3" at 10 yds and at 17 ft.

As you move further away from 10 to 40 yards parallax becomes less and is almost zero at 50 yards.

If the sight is parallax free at 10 yds or 17 ft, it would be way out of alignment."

So there is a minute amount of parallax, but that's the nature of the beast with a holographic RDS.

BTW: I run an EoTech 512 on my 16 inch AR and a Vortex SPARC on my 10.5 backup. I use both for CQB competition, and have not found parallax to be an issue with either, even when shooting over simulated hostages or the like. Scope hold over ends up being more of a factor at very close ranges.

If you're looking for RDS recommendations you'll invariably wind up with the Eotech vs. Aimpoint argument. IMHO this is a Ford vs. Chevy or Glock vs. M&P argument... Still, I'll offer you my EoTech koolaid:

-Most importantly I find the EoTech "donut of death" much faster than a single fine point like an Aimpoint or SPARC. The 65 MOA circle is fast to acquire when tearing around a CQB circuit; I find a 2 MOA dot slows me down.
-the 1 MOA centre point can be used for precise aiming at distance, especially when coupled with a GOOD magnifier.
-Speaking of magnifiers: I originally had a Vortex VMX3, and my shooting partner had an Aimpoint 3x. We both dumped them in favour of the EoTech STS33 finding it was an excellent balance of cost and quality. They're not cheap, but they are robust and easy to use, and still cheaper than the Aimpoint equivalent.
-I find the BIG window of the EoTech easier to use than the smaller sight of an Aimpoint or SPARC. This is particularly true when messing about with VTAC boards, getting into "urban prone", etc. Smaller sight requires more effort to get into the correct position to see the dot... It's tough enough when I'm contorting my fat a$$ to get into urban prone to shoot!!!
-I opted for a 512 as I wanted to be able to use AA batteries and had no issues of rail space on my flat top AR.
-Aimpoint fans will cite the 5 year battery life as a factor; I use my EoTech A LOT, and just replace my batteries once per year. I've not run into dead batteries yet.
-Barring failure of your RDS you'll not use your BUIS for CQB... RDS is much faster and more accurate. There's a reason why they invented and deploy them.

For your consideration... I'm sure others will have input too!

 

[J Whisky]

AFAIK EoTech and Aimpoint are as close to parallax-free as possible. An EoTech technician shared the following info about the 550 (and all EoTechs are pretty much the same):

"The sights do have parallax error of +/- 1.2 " or +/- 0.6" (1.2 " side to side). The sight is designed to be parallax free at long distance 100yds to infinity. At close range, there will be a parallax error equaling to the width of the window which is 33mm or 1.3". A perfectly aligned sight will have parallax error of 1.3" at 10 yds and at 17 ft.

As you move further away from 10 to 40 yards parallax becomes less and is almost zero at 50 yards.

If the sight is parallax free at 10 yds or 17 ft, it would be way out of alignment."

So there is a minute amount of parallax, but that's the nature of the beast with a holographic RDS.

BTW: I run an EoTech 512 on my 16 inch AR and a Vortex SPARC on my 10.5 backup. I use both for CQB competition, and have not found parallax to be an issue with either, even when shooting over simulated hostages or the like. Scope hold over ends up being more of a factor at very close ranges.

Awesome, that last bit was exactly where my mind was at. Thanks.