Rock River LH Upper Compatability

[Walt Schmidlin]

I have a LH Stag upper which works well on a Colt lower. Want to purchase a Rock River LH upper but the Rock River website specifically says for Rock River lowers only.
Does anyone have any experience with a LH Rock River upper on something other than Rock River lower or is this just a CYA by Rock River.
Thanks

 

[DocBII]

Walt,

Two major types of uppers, based on the shape of the back of the upper. The Rock River and I believe Colt use a straight back, and the DPMS style uses a round back. DPMS is the most common type at this time.

HTH,
DocBII

 

[Fast14riot]

Rock river Lef-T lowers have right side bolt release and safety, ambi mag release.

 

[Walt Schmidlin]

Appreciate the info, will visually check Colt, and my friends RR and DPMS lowers.
Learn something everyday, thought all lowers were created equal excepting smaller trigger pin holes on some Colts.
Thanks again.