I've used BH209 with 3 different CVA guns (2x Accura V2 and 1 Accura MR). Get the BH209 breech plug- I haven't used it with 150 containers of BH209 but looking at the two side by side I'm not sure that simply drilling it out would work the same way. You can see the difference just google CVA BH209 plug.
What I found was a noticeable positive shift in accuracy using the BH209 specific plug instead of the factory plug. I'm assuming the ignition was better/more consistent. I managed to ding my chrony with a sabot so I can't quantify other than groups went from 2" inches at 100 yards to 1" at 150 yards with a 3-9x leupold.
