APS M4 CQB-R Convertible Barrel Adapter / Extension Set (Thread: 14mm- Negative)

"It may not be shooting straight due to the fact that theres a longer outer barrel and not a inner barrel. You may need to buy the correct inner barrel length, if you have the inner barrel u may need an entire new hopup system or to adjust your hopup correctly

"This will fit any 14mm negative thread. (DBOY has 14mm negative FYI)

All 3 sets can screw onto each other and so it can be used to install a M16 free float on a M4 if you want to convert your M4 into a M16....

"They are good but they're kinda hard to take apart once put together and they scratch pretty easily

"yes it does attach like a silencer but they thing i noticed on my gun is it iisnt the same diameter as my barrel, it could be just because i have a classic army scar but im not really sure...... it might be the right diameter for a m4 or m16, but not my scar...... still this is a great barrel extension! slightly on the heavy side but very good.....

"does you put this in as if it were a silencer, or do you actually need to open uo your gun and put it in, becuase I really don't know what im doing here if I have to rip open my $200 M4

"I PURCHASE THIS FOR MY CQB AND IT LOOKS GREAT. BUT WHEN I FIRE THE BB THE FLY OUT OF CONTROL. EVEN THE HOP UP COULD NOT CORRECT THE PROBLEM. ANY ONE?