I've got an M4 barrel with a 1:7 twist and the rails.

Am I correct that I will need an upper assembly, forward assist, a bolt carrier and charging handle to complete the upper?

Also, concerning parts, if parts are parts as I have read, what is the most inexpensive brand that I can buy and still get quality?

On the opposite spectrum, if I wanted to go with the best quality parts, would that be Rock River?

Thanks for the help in advance.

Quoted: I've got an M4 barrel with a 1:7 twist and the rails. Am I correct that I will need an upper assembly, forward assist, a bolt carrier and charging handle to complete the upper? Also, concerning parts, if parts are parts as I have read, what is the most inexpensive brand that I can buy and still get quality? On the opposite spectrum, if I wanted to go with the best quality parts, would that be Rock River? Thanks for the help in advance.

You will also need a bolt and firing pin to go with that bolt carrier

And a carbine length gas tube w/ roll pin...

And depending on the type of rails, you may need a delta ring assembly as well.

- AG

For a stripped upper you will need the forward assist, BCG, CH, and dust cover. If you dont already have a bolt for that barrel, you may consider getting a headspace gauge or some go/no go gauges.

Cheap but good: RRA, Bushy, Oly, DPMS.

BEST:Colt, LMT, Stag, BCM