Alright i just purchased a dpms bull 24 and i love it for target shooting and varmit hunting but I've decided i want one shorter and lighter this time and would really like to build this rifle. just wondering what parts are needed and such.

The wish list would be: 16inch barrel, well balanced, very dependable, affordable, four rail handguard. 

I have intentions of putting a trigicon acog on it also. so any help, advise or anything will be appreciated. 

Thanks guys

I advise you to go with gas piston, I have it on mine and have never had to clean my bcg past a light rub down. No excessive ware on any thing either. I look at my AR as my disaster gun, and if shit hits the fan I don't want crap building up on my operating parts. Look at rainier arms, they have good prices.

Bravo makes good barrels with good prices. If this isn't a precision rifle you can stick with the stock trigger, but nobody really wants to do that. Mine is a RRA 2 stage match, is a blast to shoot fast.   Think about getting a 14.5" barrel and a nice 2" long flash or muzzle brake pinned on, after building a 16" barrel, it will really be 18". Shorter is handier.  if you are thinking about an optic, aimpoint a has the best battery life, but I swear by my eotech.