Well sighted it in with Hornady 250 gr. Monoflex's pushed by 100 grains of Shooters world MPB. Accuracy even with my Grandson shooting is under 2 inches for three shots. I do have a snivel though, seems like there is a lot of blow by past the primer getting some heavy residue on the face of the reciever upper right corner. To me this breech plug is very sloppy, it beeing a Nitride aftermarket one made for 209. Primers are very loose in it and the through hole is larger than that on the new looking original breechplug. Is there any reason the original breechplug woudn't work for an easily ignited powder such as SW MPB? Should I use magnum primers with it?