I am building a light weight 16 inch carbine.Is m4 the way to go or A2?Probably will mount a red dot sight.I will most likely use all RRA?

           thanks

Do you mean A2 fixed carry handle vs M4 with a flattop? If so, then I would spend the extra few bucks to get a flattop upper-especially if you were going to install a red dot. I think RRA calls their flattop an A4 rather than A3.

A flattop can do everything that a A2 can do, and an A2 isn't as versatile as a flattop.

[img]http://home.comcast.net/~cjan99999/Hbar_m41_copy.JPG[/img]

This is mostly personal preference. Think about what you want to do with it. If it's for normal use, plinking, etc and not used for competition or really rough use, either will do the job very well. And you'll probably wind up with both anyway, since most of us seem to.

A couple of things to consider.

If you want really light weight, remember that a carry handle adds weight. Then, too, many people never remove their optics and use the carry handle anyway.

If it's for really rough use, I don't feel as secure with large optics on a flat top as I do with the standard A2 sight (and I really prefer the old A1, indestructible sights). But then lots of people find them acceptable, including our GI's.

 

Flattop is definitely the way to go, on account of its flexibility. I have an A2 and regret it everyday. If you want optics, double the recommendation for flattop.

But.. if lightweight is your #1 goal, an A1 is the ultimate choice.