Chioke Williams, Daniel Dubidat, Jason Woodley and Nathan Ali received sentences of between four and a half and six years.
The four men had robbed a mini-market, a grocery store and an off licence in May and attempted to rob the Good Cheer off licence and convenience store in Hamstead before being confronted by owner Reg Rowe. Members of the gang fled empty-handed and were later caught by West Midlands Police.
Reg, who refused to hand over the store's takings despite being threatened at gunpoint, said: "A bit of justice has been done to say the least.
"I'm glad they got sent down, they'll have a black mark against them for the rest of their lives, although personally I don't think it's enough as they'll only serve half the sentence."