I'm using these https://tinyurl.com/yb6zccs9 for the Black powder 12 bore and they can be "cut to length", so no problem with filling.
As for "punch", because the targets are these![]()
not these:
and the general distance will be 20, max 30 metres, I don't anticipate a problem >)
Thank you for the offer of the "dig around" re subsonic assistance.
Bookmarks