I have two methods I use for days I seem to be having trouble pouring prime from my main horn, or with horns that make it tough.
One, pour a small amount into the powder measure, pour into the pan from that using index finger to control flow.
Two, a small antler priming flask without the plunger tip.
View attachment 128837View attachment 128838View attachment 128839
Behold the prime ejaculator, lol
The end plug is held in by the round leather thong that goes through a hole drilled straight through antler and plug. Pipe bowl used for scale.
There are options.