5KU Machined Outer Barrel for TM M4 MWS Series Airsoft GBB Rifles (Style: CQB / 7")

"Tokyo Marui MWS Carbine - 5Ku 10" barrel length

It's really straight forward to replace the outer barrel, the stock conical brass conical fits over the 5ku snugly and inner barrel/hop up unit fits true and snug. Eye-balling it, the inner barrel, relative to the outer barrel, it's pretty centered. With the stock inner barrel, the barrel falls short by 4.8 mm. Fits into the upper receiver no problem.

Cons:
It isn't a one piece, there are two pieces to the outer barrel, the main base (that inserts into the upper receiver) and the shaft that fits into a cylindrical base of the main base and is secured by two grub screws at 12 and 6 o clock. There is enough tolerance between the base and the shaft that it'll un-tighten the grub screws loose, making the outer barrel wobble. To minimize this tolerance, I've carefully wrapped teflon tap to the shaft which did take out significant amount and blue loc tite the grub screws. Hopefully this'll be a semi permanent solution, otherwise I'll be trying retaining loctite (green) to secure the shaft.