ah yes, the NMLRA ... we knew and loved you SO well, SO many decades ago, now look what you've become. yuck.
traditional muzzleloaders are a niche sport at best, nestled in the now much maligned and literally hated "American gun culture". the bottom of the firearms totem pole in terms of popularity when ar15s and glocks are the darlings of young and old alike. sure, the public interest spikes when period hollyweird movies make their brief scene (jeremiah johnson, the patriot, the revenant, etc), and then interest quickly wans.
the NMLRA was a fine organization whence it was first contrived. their focus, goals, and ideals were all something to reflect and admire. today, that org is a mere ghost of what it was, and in every manner possible. once a certain group assumed the NMLRA helm, things started heading south in bad way. one of the first things the NMLRA enacted was to ban "blowing down the barrel". the ban was to clearly to appease the public's misconception of that
important safety practice. when the overall American interests in all things trad ML started to dissipate, and the NMLRA was feeling those monetary impacts with regards to footing all the bills required to keep and maintain their Friendship range and headquarters, desperate measures were taken. first up was to acknowledge and support modern inline muzzleloaders. eventually, 19th century cartridge rifles were also included. so yup, this isn't Kansas anymore, Dorothy. the NMLRA bubble done got burst and it's no longer anything like it was from the get-to. the main reason is Friendship and the overwhelming need for survival capitol.
for more about "blowing down the barrel" and the NMLRA ...
http://bwanabob.info/page2.html