Cleaning Grendel chamber

[Bedford]

Hi,

Any tricks in cleaning the chamber in a Grendel AR15? I've got some carbon build up in the shoulder area that I can't get to. The regular .223 chamber brush is too narrow. I've tried wrapping a few patches on the front of the brush, but it doesn't work. I've tried .40 and .45 pistol brushes, this doesn't work either. It is a chrome lined chamber and bore, so I'm not too worried about it hurting the chamber. However, I'm running a suppressor and get a lot of back pressure filling the chamber with soot. Since I can't get the chamber completely cleaned, I can only shoot 60 rounds or so before I start having malfunctions.

Would an AR10 chamber brush be too much?

Thanks!

[wheelguner]

The best thing I've found to get rid of carbon is General Motors Top End Cleaner. I apply a generous amount with a 45cal Mop and let it work for a while and reapply as needed. The stuff is REALLY NASTY Smelling and for safety sake work in a ventilted area. I have friends that use Mercury Outboard Carb Cleaner and seem to like it. Works well on bolts and carriers also.