The PBR, Portable Barrel “Rench”. Shown here in the stowed condition, with the included 3/16 hex wrench lightly clamped between the two halves by turning the cap screws finger-tight. This minimizes its size for in the tool box.
The PBR is a tool for stabilizing and isolating the barrel while removing / installing muzzle devices. It is made mostly with the AR15 in mind but offers the same advantages to pretty much any design, mainly, keeping the torque and counter-torque isolated to the barrel end and the item being threaded off or on. Using this prevents the barrel from threading out of the receiver or barrel extension instead of the muzzle device breaking loose. It prevents any movement of the AR15 barrel extension under the barrel nut.
I never liked the idea of using the whole gun as a wrench against the wrench getting the flash hider or whatever off—like, pistol grip between the knees style. Done this way, if the barrel comes out of the extension, that’s probably where the problem was and it might have happened all by itself later. What always worried me was shifting the barrel extension from side to side in the upper receiver every time something at the end of the barrel is loosened or tightened. Some rifles tend to get the muzzle device changed regularly-- this could eventually lead to a barrel extension that can shift side-to-side under the barrel nut, or worse.
Installing, below. You can basically do this in your lap, or holding the gun with one hand and tightening the muzzle device with the other—both wrenches being more or less lined up. Here the tightening is done by simply closing the hand on the two wrenches. Going to a torque spec is the individual’s prerogative of course. I rarely do, not because I don’t believe in torque specs, just that my pref is go on the light side of what will stay tight and I’ve acquired a pretty good feel for it. Your bolt carrier becomes the leverage for the PBR, since there’s almost sure to be one around when you’re working on an AR, right?
Tigtening again….
Loosening:
The PBR can also be used as a gas tube clamp. No telltale ChanneLock marks :-) :
….and to help stabilize the buffer tube when loosening and tightening castle nuts. It can be a struggle keeping the buffer tube from turning with the nut, tearing the receiver plate’s key through the soft aluminum threads. Yes, I have done it.
It’s made from certified US-made 7075 aluminum and 1018 steel, and the cap screws and wrench are US-made. Barrel diameter range is < .625 to > 1”. I usually wrap a piece of paper over the barrel first to keep any aluminum from scraping onto it.
These are $105 plus $10 Priority Mail. PayPal: ned dot chr at gmail dot com, or send a check made out to Michiguns to
MG
Box 42
Three Rivers, MI 49093
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