I have a flat receiver action wrench I made using two 1" square steel bars with two clamping bolts. One bar is longer and is turned so a piece of pipe will slip over it. I use a couple of shims to protect the receiver finish. Have used this wrench successfully on 99s, Ruger No. 1s, Win 94s, etc.
I believe a Brownells wrench could be used with appropriate jaws.