APS 15" Outer Barrel for M4 / M16 Series Airsoft AEG Rifles

"This barrel is great and all, but I had a problem getting my barrel nut over the lump at the end. So, if you buy this, you might have to get a Dremel and grind away at the barrel nut.

"This barrel is awsome but be sure to buy either barrel spacers or a 407 mm inner barrel cause inside of the outer barrel is hollow and it will cause your inner barrel to not be flush with your outer and then you cant gett bbs out properly. Also it has 14 mm negative threads in case you were wondering. And yes it fits on my g&g gbb.