question can I shoot regular reenacting blanks in my .303 rifle in a grenade launcher shooting tennis balls or do I have to use special ones.? any info appreciated.
No these were 7.62x54r blanks and they will definitely launch a tennis ball a long distance. Op, just curious, you make a homemade launcher or are you a reenactor? The one I used was not mine but it was a simple pipe fitted to the end of a 91/30. Also got to play with the groups mortars.
If you reload you can drop 1o~15 Gr of pistol powder in a primed case & seal it with soap. Just push twist & pull.
Clean with hot water & the soap is in there anyway!
It'll fling a tennis ball about 75 yds or more.
Here's my No4 spigot type with its dual tennis ball discharger attachment!