Do you like Probability? Do your like using weapons with a Rate of Fire > 1? Have I have written the AnyDice for you!
https://anydice.com/program/26f54
However, AnyDice basically doesn't handle dice about d10 with exploding and such well. The less good looking, but still useable solution is to go to the Troll Dice Roller and use the following code.
http://topps.diku.dk/torbenm/troll.msp
\ Savage World (d10) RoF 3 w/ -4 penalty
largest 3 { ((sum (accumulate x:=d6 while x=6)) - 4 ) >= 4,
((sum (accumulate y:=d10 while y=10)) - 4 ) >= 4,
((sum (accumulate y:=d10 while y=10)) - 4 ) >= 4,
((sum (accumulate y:=d10 while y=10)) - 4 ) >= 4 }
Hope this helps someone else.