I was experimenting this weekend with the new MUBP I just bought from Nick for my Huntsman.
It was boring accurate with 90 grs BH209, Hornady 250 gr XTP, Harvester short black sabot and Rem STS primers.
For excitement, I decided to try some of the "for muzzleloader" 209 primers. Specifically Winchester T7 and Remington Kleenbore with some Remington 209-4 (for .410) primers thrown in as well. I forgot to bring along the Vari-flame adapters but that will just give me another reason to play another day.
I was not shooting for accuracy so I don't have any targets worth posting but all three worked fine. Not a single hang fire or even the slightest noticeable delay. This was on a 75 degree F day so I will not speculate how they will work in much colder conditions. It was just neat that they fired so reliably and gave me an opportunity to use them up.
In summary, there was zero noticeable blow back in the breech area of the gun. It is hands down better than the factory plug and I would even share my opinion that it is better than the .25 ACP conversion plug that I have used for the past several years.
