The Howler cannon Mk. v

so i built a high power rapid fire cannon. I got board so I started to mess around with the normal TnT cannon disign and then though, What if i made if it rapped fire? so after acompilshing that I thought about how far I could get it to fire. So I added more Despencers to both sides, the top & bottom. After that I relised that adding more power wasn't going to do any thing if the shot exploded before, or right after it was lanched; so I made a delay system. Once I had finnished that I relised that it could be even more rapped fire if I changed the button I origonaly used with a lever. So then I did that, made it look pretty and here it is; The Howler Cannon Mk. V