Semi

Just my opinion mind ya, but even with hotter 209 I do not think it would be reliable... That flash channel allows heat andflash to escape the primer and also creates sort of a vortex to pull moreheat and flash out and into the flash hole.

If you look a White nipple Doc did it just the opposit, that is why the #11 cap is so reliable in a White ML... the flash hole is almost directly under the primer and the 1/8" flash channel is on the other side down into the powder... this really is effecient. but itis a bit dirty - not blow back but soot from the primers or caps...

I would still probably try the hotter primer but I do worry about reliability especially as the BH-209 fills up the breech plug and it does not take long.