Hey everyone!!!
I bought myself my first blaster a couple months back and played a few matches which I love.
I know nothing about the technical side of these things and I want to know more, particularly how TF do I swap out the barrel and make it into CQB?
My biggest mistake was not looking into that as I always smash my barrel into walls while taking cover etc.
pretty sure the inner barrel is 385mm at the moment and I have a DB FH Hopup on there too. Any advice on what size barrel/outer barrel adjustments i’d have to make to successfully do this whilst keeping my hopup/FH on too.
Any and ALL advice would be super bloody helpful here, as I love this hobby but struggle to understand the finer details on how to make my dream blaster/s etc.
Thanks y’al! 
The end section of the outer barrel may be able to be unscrewed (may models do this, can not remember if the Double Bell do).
If it can, all you need to do is trim the inner barrel down and you are good to go with a “CQB” M4A1.
If not you will need to change the outer barrel to a shorter one, and likely the handguard as well as not all aftermarket outer barrels will support the hardware for the stock clamshell handguard.
Dropping the inner barrel size should also help bring FPS a bit tighter spread and match the cylinder volume too, really the only potential downside is you may lose some FPS, but given these are pretty hot standard it really isn’t a downside- I would take the consistency of the shorter barrel over the top potential FPS these offer any day.
We are all here to help and provide advice as you go, so ask away 