The other way of thinking is someone making a AK47 type weapon and marketing it in the Thompson SMG area of the Market.
This might be a Good sell in US/UK was there long history of Musketry/ Marksmanship had such a popularized history
This from
http://world.guns.ru/assault/as01-e.htm for the AKM/AK47
Caliber 7.62x39 mm
Action: Gas operated, rotating bolt with 2 lugs
Overall length: 870 mm
Barrel length: 415 mm
Weight, with empty magazine: AK 4,3 kg; AKM 3,14 kg
Magazine capacity 30 rounds (40 rounds box magazines and 75 rounds drums from RPK also may be used)
Cyclic rate of fire 600 rounds per minute
Compared to Tommy gun
M1928
Caliber .45ACP
Weight, empty 4.9 kg
Length 852 mm
Barrel length 267 mm
Rate of fire
Magazine capacity 20 or 30 rounds
Effective range 100-150 meters
The expensive Tommy Gun found markets. So maybe a Cheaper Marketed option called a long Range SMG might sell ( the German MP43 finally became the Stg 44 sold to Hitler as a SMG not a short automatic Rifle
http://world.guns.ru/assault/as51-e.htm )