If you're cleaning a mil-spec flattop or A-1/A-2 receiver, Brownells Upper Receiver Action Block is also an excellent choice. This block was originally designed to provide the gunsmith a safe, effective way to tightly clamp the upper receiver in a vise for barrel installation and removal. With the upper assembly removed, it works equally well for bore cleaning. The block is supplied with a cylindrical, internal support tube to prevent damage to the receiver when torque is applied to the barrel nut. This piece can be set to the side when using the action block for cleaning. Because the block fits around the receiver, it requires the dust cover to be closed or removed. Therefore, it's best suited for use with a muzzle guard, or one of the small diameter bore guides that clear the dust cover latch. These include the Dewey AR-15 Bore Guide and C.J. Weapons Bore Stay™. The Stoney Point XL-101 Chamber-All Bore Guide with optional, XL1 1" Diameter Collar also works great, as well as their XL-303 or All-In-One™ bore guides when used with the XL3 1" Diameter Collar.
The injection molded block features an innovative hinge system to completely "sandwich" the receiver between two pieces of non-scratching Rynite. Once clam-shelled around the receiver, the lower portion can be clamped in your vise to immobilize the upper assembly for cleaning and repair.
Several options, all different, all available to you from Brownells. One of them is certain to fit your cleaning style and make the AR-15 more manageable to handle while cleaning.
If you have questions about different cleaning products or techniques you want us to test, be sure to let me know at WebBench@Brownells.com.