Muzzle loader shooter I know made up one of those tire tunnels some years back, about ten feet long, quieted down his flintlocks and caplocks very satisfactorily. Stuck the whole front end of the rifle up to the trigger guard and lock into it. Unknown to him unburned black powder collected in the tires and about the third summer he got a terrific flashback which (1) scared him sh--less and (2) singed his eyebrows. After recovery from this nasty surprise he made holes in the bottom curve of the tires and flushes them out with a hose a couple of times each summer.
