New M4 is jamming a lot

[Zeta Crossfire]

Here's kindof a no-brainer...
When you stuck a cleaning rod down your gun's barrel, did you turn the HU off first?

Also please describe the jam. Is it failing to feed or are BBs feeding into the HU and then getting stuck there?

It's getting caught at where the bb enters the barrel, usually I can see the BB thats stuck in there.

*to add*

Just got back from shooting it outside and it's still jammin... If I open it up I'm going to screw over my weapon so I'll bring it to S4 in the next few days, thanks for the help guy's.

[Bush Killer]

I've seen some issues where the bucking is actually not stiff enough and the lip will fold over and jam the BB. A bucking replacement should be sufficient; I've always fixed jamming issues with a bucking replacement.

Another possibility could be your BBs. Tolerances vary from rifle to rifle; for example, I had an SRC G36E that absolutely HATED Madbull BBs. One every fifty or so would mis-feed. I literally could NOT get through a mag. It loved G&G BBs though. The size difference was tiny; ~5.98 vs ~5.95, but the it did make a difference.

Maybe list what kind of ammo you're using?