As MSAR prepares to release the E4 and MCS, I'm wondering something.  Can you switch between top rails of different heights?  I know that some of the generations used lower rails while the current ones use a higher rail.  I prefer as low a cheek weld as possible and would therefore like to eventually buy one of the older "low rails" and install it on a new rifle if that's possible.  Thanks!

Well, yes and no...

I believe the RAIL heights between the older (Gen I-IV) guns are the same as the soon-to-be-released Gen V and E4.

It's the factory 1.5x OPTIC is higher on the upcoming Gen V and E4.

And yes, according to MSAR reports, the new higher 1.5x optic will fit the older guns (so I would assume the older/lower optics will fit the newer guns, too).









Now if I'm wrong, though and the rail heights have changed, too... I would assume the same would be true when considering old vs. new rails since they all use the same attachment set-up.

We are about to release our higher optic, the rail height has remained the same since the first rifle.

Yes, if anything we need a "lower rail" for the railed STG's.

Come on Rizzo.

I agree.  It's over .46" higher than the AR rail making using AR BUIS a bit of a...chin weld affair.

Oh man!  Screw that...I want it as low as humanly possible.  That way, for those of us who prefer a low cheek weld, it's perfect.  And for those that prefer a higher one, there are rail risers available all over.

1/2 lower ?   then your right back were you started with  " the optic sits too low " complaint.

We're talking about the rail not the factory optic.

AR BUIS would be the appropriate height on the MSAR if MSAR lowered the rail .46".  Most optics/mounts are made to cowitness with AR BUIS so they would in turn also be the appropriate height.  Lowering the rail would help everyone out.

Well in all honesty, it's all relative.  As long as your mounting both your BUISes and optic on the same rail, it doesn't matter how high or low the rail itself is.  Both sighting systems are mounted on a "relative ground zero", if you will.  But I think that a lower rail is preferred because it affords a tighter cheek weld.