Trying to determine what parts to buy to build up an M4.

Leaning towards Colt... because of the history... quality... and resale value.

Definitly want a Colt mil-spec upper. (sans bayo lug and with welded FS of course. :-)

What are the differences between post-ban lowers?

I've heard something about Colt's not having mil spec tooling... trigger group pins or something like that?

I don't want something that would not be compatible with common parts... or something that is out of mil spec. Going for authenticy...

Can someone elaborate on the differences... and mabye rate the quality of the two?

Also... any idea of prices and places to buy a Colt reciever? I had heard around $200 stripped.

Thanks.

Sadly, Colt lowers will use non-standard trigger pins, and possibly front take down pins. They will also has the Colt sear block.

Rock River will use all standard parts and pins. As will almost any other lower from a quality manufacturer. I am also pretty sure Colt doesnt sell lowers only. So I'm not sure you'll find a stripped one. Rock River's stripped lowers are going for as low as $110 at the moment.

What new-arguy said!

Do the RRA lower and be HAPPY! I'm about to do a RRA M4 myself.

Me too.

resale would be the ONLY reason to buy a colt lower. and not enough reason for a shooter IMHO.
the "colt only" bigots make me chuckle.

(sans bayo lug and with welded FS of course. :-)

i hate nit-pickers, but- you mean kkf, wilson, or egw comp- right?

Quoted: (sans bayo lug and with welded FS of course. :-) i hate nit-pickers, but- you mean kkf, wilson, or egw comp- right? hr

But of course.