I recently picked up a Vortex Sparc to play with on 10/22 for some fun matches. The rifle has a Knoxx pistol grip stock but so this isn't any kind of AR clone therefore i'm limited to just 6" of rail on top of the receiver to pick a position. Vortex says to mount it at least 4" for eye relief so thats not a problem, the closest position on the rail satisfies that point WRT my cheek weld.

 

This is my first red dot on a rifle so i'm not well versed with the advantages/disadvantages of mounting them long or short. Looking around the web, i see both extremes and everything in between so thats no help. Commonly i see the discussion in regards to an AR15 which doesn't apply to me I've noted some of the various talking points below for the differing positions to start, but other than that, i'm curious about what are some of the other philosophies of use in where you mount it?

 

Close

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pro - Largest field of view available through the tube.

pro - front end lighter

 

con - Dot size grows.

con - interferes with BUIS (if u have them)

con - scope controls interfere with other eyes view of periphery.

 

Far

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pro - Dot size is smaller

pro - Can use BUIS

pro - less interference of view periphery

 

con - FOV gets small

con - front heavy

I have a red dot scope I used to use. I preferred the red dot mounted rearward for precision target style shooting. I really liked the forward scout-style setup for point-and-shoot shooting. If I were going to use it in a match where I was walking around shooting at targets, I would use the scout mount. If I had to put three shots in the tightest circle, I would use the traditional setup. That was just the conclusion I came to. People who are more knowledgeable may have a different answer.

What Chris (Lunker) said is 100% correct.

From my understanding about RDS systems that are parallax free, you want to mount them as far forward as possible. I'll try to do some digging for where I read that.

I know that some red dots and the eotechs reticule size changes, further forward the larger it becomes. Personal preference really. Eye relief may play a role if its not unlimited.

Personally i like my eotech mounted forward, however, if i were shooting past 100 yards i would pull it back, reduce reticule size and improve accuracy. Some people say the quality of your eye sight will be the biggest factor.

 

Parallax free means nothing unless you buying an aimpoint or eotech, or something of similar quality. I know the Eotechs use a curved lense to create PF and aimpoints use a different method, but neither are completely true Parallax free. I would say that the further forward its mounted the harder it is to get the reticule into a space where Parallax becomes an issue, as it's easier to create more angle the closer you are to the sight.

 

Some people can actually see where parallax occurs in a scope using Polarized glasses, the Dot will disappear when the angle is off.

I mounted my red dot where it balanced the best on the rifle, period. Unlike magnified scopes, you should mount them where it works for YOU and where YOU can use them best.

It depends on the system and application. On my SCAR I have my T1 mounted foward about 4 inches so that my PVS14 can mount behind it. On my Colt its dictated by the mount with BUIS.

I got my red dot mounted evenly above the magazine so its about mid way