308 AR Rail height

[AlterEgo]

Hi Guys,

I'm designing a new 308 AR upper/lower combination.

The 308 AR patterns that are out there that come to mind are DPMS, Knight, and Armalite. I know that DMPS has moved around their rail height on the upper receiver to the chagrin of many.

The basic specifications I am designing for is DPMS. As is typical for the 308 (there being no .mil spec) I am going to incorporate some things Armalite into my design. That said, the barrel nut and rail dimensions will be 'DPMS'.

What rail height would you guys recommend designing for, and why?

Thank you for any help in advance!

 

[Drifter™]

An important factor might be which height / platform has the most handguards available. Nobody wants a receiver and handguard with top rails that don't match up appropriately.

 

[wareagle700]

Most 308 rails now use the height designed for the older DPMS A3 receivers (which are a little higher than the new ones), SI Defense, MEGA MA-10, and KAC.....IIRC.
Even though there is no "standard" I'd say the most common used heights are still those for the KAC, MEGA MA-10, and SI defense.

 

[AlterEgo]

Ok, got it. Sounds like the older (higher) DPMS height is the way to go. Anyone know the rail height from the centerline of the barrel?

 

[biner626]

Most 308 rails now use the height designed for the older DPMS A3 receivers (which are a little higher than the new ones), SI Defense, MEGA MA-10, and KAC.....IIRC.
Even though there is no "standard" I'd say the most common used heights are still those for the KAC, MEGA MA-10, and SI defense.

This, I believe the Armalite is the same height.
What would be nice is if someone made a barrel nut for the different Threads that would work with one rail system. Of course the rail would be the most widely accepted height.
One could even have a menu to select the barrel nut/select rail height.
It would also be nice to not have to eff with indexing the barrel nut.

 

[KevinB-KAC]

I'd argue their is a Milspec for 7.62mm AR's
10K+ Mk11 Mod0
3K+ Mk11 Mod2
9k+ M110 in government service...

 

[wareagle700]

I'd argue their is a Milspec for 7.62mm AR's
10K+ Mk11 Mod0
3K+ Mk11 Mod2
9k+ M110 in government service...

There may be a milspec for those. But the platform in general has not been standardized.