Responses so far use the word "make". Do consider making yer own. To me, that is a big part of the fun of this ml insanity. I have made many measures of several types of material (horn, antler, wood, copper pipe, even goat horn). Quite easy to do. Make a bit oversize then stuff something in the end to reduce charge or cut shorter.
I'm a little lazy for the pic taking this this a.m. But, the soft copper pipe idea is a good way to start and very simple. Using yer adjustable measure, set to volume desired, take a good look at it and, in yer mind, try to remember wat it looks like. Then cut the pipe, guesstimating, over length. Hope you allowed about 1/2" at the bottom.
Then just squish the bottom in a vice, drill a thong hole, grind off the sharp corners and use. In very short order the thing will get a nice dark and grungy patina. It will blend in nicely with your other fake rendezvous accoutrements and you will be on yer way.
For rendezvous use, I make mine a half-charge (e.g. 35 gr.) since most targets are novelty types at very short range. If needed for longer ranges or hunting I just measure twice. (that makes 70 gr. if ye ran out of fingers. :wink: )