For reasons not understood, Remington often installs the coupling so tight, some of them get damaged during removal.
They've been told over and over MANY times that they're installing the coupling too tight, but they continue to do so.
The don't seem to do this on the Police guns. Why they do it on the commercial guns is a mystery.
To remove, use a small strap wrench or a large set of well-padded pliers to get a good grip on the coupling.
If you damage this one getting it off, contact Remington and complain. They'll send you a new one.
To reinstall, screw the coupling on finger tight, then give it one more "click".
The coupling should be snug against the barrel ring and the barrel should be tight in the receiver.
However, you should be able to remove the coupling with just your fingers.
When installing the extension tube, screw it in until it JUST contacts the guns magazine tube, then install the clamp.
If you screw the extension in too tight, the pressure may cause the two tubes to misalign, causing stoppages.
If you don't screw it in until the makes contact with the magazine tube, there may be a gap that will cause stoppages.
