Here's another one chambered in 5.56. It was built a little on the cheap but has room to grow. Weighs 6lbs 12oz bare.
-BCL (IBI) stainless 18.6" fluted mid-length gas 1:7" twist barrel
-Geisselle .750" stainless gas block
-MRA V1 M-LOK 13.5" handguard
-MRA stainless gas tube
-stainless bird cage flash suppressor
-BCL BCG
-BCM Gunfighter charging handle
-DPMS dust cover
-Anderson LPK
-BCL milspec buffer tube (a little loose in the CTR stock)
-ATRS's generic buffer and spring (unknown brand)
-Magpul CTR stock
-Burris PEPR 1" mount
-Leupold 3-9x40 American Marksman
2nd pic (with much nicer optic)
-Aero 30mm mount
-Premier 3-15x50 Gen II XR
I have around $2030 into it without scope or mount.