I've been shooting Bookes USA enhanced .30 mortar since I got it on the 3rd of July . I learned some and made a slight change .
Regular firecrackers worked OK but w/ only about two seconds of flight time ,ok for a shell gun or howie .
So I got some fancy firecrackers "Blackcat brand" has them , I like "Bunker Busters" better . Both brands come in 100 packs bulk packed not woven together like regulars . The best thing about these firecrackers is they have nice little green cannon fuse
.
I 've gotten up to 5-6 secs flight time w/ them . They are the same size firecracker as usual , the construction is differant though, they use a tiny bit of powder w/ over half the "shell" filled w/ clay plugs on each end more .
ONE problem the better fuse is thicker (.050") ,meaning tight bore ,so tight that what usually happened was Blammo everything goes off in the bore ..... I bored it out to .310". and now use 5 grains of powder . I usually also leave a bit of gap between the powder and bottom of shell . It seems to light them better . If I was to have realized that I would have drilled only most of the tube leaving a bit of a chamber in the bottom . The cleaner the bore the longer the flight time it seems , as the bore gets dirty more pressure seems to light up on the fuse somewhere so time is shorter . Times are very reliable right at 5 secs when the bore is clean .
Now I tape the fuse down along the side of the "shell" exposing only the tip so it won't want to light up on the fuse somewhere . Then for reliability I paint on a slury from tip of fuse to the bottom of the shell basicly in touch w/ the powder except for the small gap I try to leave . I dont think there would be any problem timing them for airbust , but it's a hoot popping them across the yard in high arc then watch them sit and sizzle then bang .
The better class cracker are $1.25 per 100
rocklock
rocklock
