advantage of various upper rail heights?

[Scott Clearman]

So, I"m slowly gathering the pieces and parts for a rifle. For the record my plan is for a hunting gun, budget build. I"m not looking to drop lots of money for no reason, but at the same time quality parts are worth it. 

This is a DPMS pattern lower, actually an 80% I'm starting with.  My question is about the rail heights on the uppers. I understand the differences, what I don't understand is the reasons and advantages of the different heights.

Please give me some advice on which height I should be considering.  What does the height affect? Scope mounting? 

[BrianK]

I don't know about rail heights, but I like to raise my sight so that I'm not skoonching my head down through contortions to see through the sight(s). I've had people comment on the height until they try it. Just raise the gun up and put the buffer tube where it's comfortable and look through the sights, no contortions required. The downside? The distance between the barrel and the sight can be large and that needs to be taken into account when the target is close for pinpoint accuracy. Unless you're squirrel hunting pinpoint accuracy isn't required. Raising the sights up also allows the buttpad to actually be in place in the shoulder pocket and not floating above it. Yes, sights that high will look strange, but they're there to actually work and not for looks. Straight line recoil stocks require raised sights. That's just the way it is. 

I hope I addressed your question. It doesn't take a fortune to have various height "mounts" in stock. There are risers available to add or remove height as needed and they can be stacked to find what you need. 

edit: I don't see your location, but if you were near me (probably not) we could fit you to find what you need. 

Edited May 9, 2022 by BrianK

[Scott Clearman]

Thank you, I'm in Texas, near Dallas for the record.  

Which one of the rail heights is closer to, or the same as the height of a standard flat top AR15?  I already have that to compare with both open sights and scope mounts.

Just to make sure, no real functional difference, more a preference issue?

[98Z5V]

10 hours ago, Scott Clearman said:

 

Which one of the rail heights is closer to, or the same as the height of a standard flat top AR15?

DPMS High is standard .308AR height.  DPMS low is supposed to the the same height over bore as AR15.

[Scott Clearman]

10 hours ago, 98Z5V said:

DPMS High is standard .308AR height.  DPMS low is supposed to the the same height over bore as AR15.

Perfect! Exactly the info I was looking for. 

Thanks!

[Armed Eye Doc]

22 hours ago, Scott Clearman said:

Thank you, I'm in Texas, near Dallas for the record.  

I am South of Dallas a bit and avoid it and most big cities for that matter.

[msgriff]

Some measurements from the centerline of bore to the top of the Picatinny rail. These were mostly measured or compared by myself and are not represented as a spec.

 

AR-15                 ~1.215"

DPMS low          ~1.253"

DPMS high         ~1.313"

DPMS target      ~1.638"

ArmaLite AR10  ~1.318"

PSA PA-10 and LaRue PredatAR are in between DPMS high and low

Most small frame .308's, like the DPMS G2 and the POF Rogue, are AR-15 height.