Help needed; Colt R6600 conversion to flat top

[Bumbellybeak]

Hoping to tap into your knowledge and experience.

Thinking about converting an original Colt R6600 which has the A2 carry handle upper to flat top.
I understand not all the ones out there will work because of the difference in hole sizes.
Likely to use the same bbl. What options exist for a stripped flat top upper receiver on an original Colt R6600 which has the A2 carry handle upper?

 

[ORD]

Well...you can find an OEM Colt upper (even possibly trade your A2 for the flattop) or you can buy a conversion upper made with the proper size pin holes such as this one made by Daniel Defense:

https://danieldefense.com/big-hole-upper-receiver-assembly-b.html

Now...with that said...I have ZERO idea where you can find one in stock currently. There may be other companies making large pin uppers, but the DD is the only one that comes to mind at the moment.

OR...the cheaper and arguably somewhat simpler solution is to just run an offset pivot pin/screw and be done with it. That will allow you to run any standard, current production, 1/4" hole upper on your Colt's 5/16" hole lower. They are somewhat of a PITA if you want/need rapid ability to pull your upper completely off your lower as you need dual screwdrivers to install/remove the pin, but they do work. I did this on several different Colt lowers (especially SP1s) during the '94 AWB. This is the pin/screw I'm talking about:

http://www.midwayusa.com/product/316328/dpms-offset-screw-and-nut-ar-15-matte

Good luck!

 

[Bumbellybeak]

Heyya Sarge, thanks for your suggestions; both good. I'd rather go with the Daniel Defense stripped upper, but looked around and you're right.. didn't see anyplace that had one in stock.
Maybe someone will read this & know a place that has one.
Anyway, I appreciate you- for your great suggestion & for your service. Thanks