I want to build an M16A4 clone since I have a M16A1 clone, M16A2 clone, and multiple M4 builds.  I have gotten where I like 20" barrels, so i decided to build M16A4.  

The spec for the builds will be as follows:
-Anderson Manufacturing A2 Lower ($65 from my local mom & pop store)
-$50 dpms lpk
-Anderson Manufacturing M4 stripped upper
-KAC rails
-Windham Weaponry 20" 1/7 twist barrel
-BCG (first one on sale)
-A2 buttstock kit
-MaTech rear sight

My question is whether I'll have to get a taller front sight since it isn't F marked.  I looked for other builds that people have done but aren't having much luck. Any help will be appreciative

I built an A4 with a Green Mountain take off barrel, non F marked FSB and a GI Matech rear BUIS and it zeroed fine. Standard front sight post as far as I can tell.

You could wait to see if the BCM standard 20" upper comes back in stock. They are shipping with free BCG right now.

The KAC Rail will cost you..........Ive seen used sets at varying prices..........and with that being said......the rougher the shape....the cheaper you can get them.........I believe........they retail for 375.00

KAC had factory blems awhile back for 150 and I've bought two very nice sets with pistol grip and rail covers on the EE for 75 and 80 dollars each.  Very nice quad rails and worth every penny even if you're not building a A4 clone.

Is your M4 upper coming with M4 feed ramp cuts?  And your 20" bbl is probably coming w/o M4 feed ramp cuts?  That's a potential bullet nose trap.  Otherwise, sounds very nice.

Yes the Windham Weaponry barrel I'm looking at has the M4 extension and the Anderson upper does as well. Should be a fun build after Christmas

Nice list!  These are addictive. I have 1 store bought RRA Operator 2, a Spikes build, separate 300 Blackout Upper with Nikon glass, just finished an AR build for the wife, and I am working on a 300 BLK pistol.  That lower is complete, but waiting on what to do for the upper.

Good luck, and post pics!

I have a A4 and am getting the parts together for an A2 but trying not to build another A4 lol