About time I showed and explained my version of a wrench for setting up a BH 209 BP.

Look at the pliers. The bottom of the handles (there's two of them) fit into the slot in the BP just like the proper BP wrench does.

Screw the new BP as far as it will go by hand. Then put the pliers handle in the BP slot. Open up the pliers so you have leverage to tighten the BP. Tighten as hard as you can until the BP bottoms on the barrel. This sets the BP for just your barrel and will keep the threads clean. Back off the BP with pliers, and then from then on just tighten it with forefinger and thumb. It all the pressure it needs, and will come off easily. Lube with anti-seize lube for all powder and pellets except for BH 209. With Bh 209 the threads in the barrel and on the BP can be left bone dry. No lube needed.