Bump fire can be achieved with just about any semi-auto by lighting the trigger pull enough to create a suppression fire ability.
There is no need to buy a special stock and by lighting the trigger pull you will help your long range accuracy.
Putting a red dot or a scope on a gun that can be bump fired can help you put a short burst on target as long as the recoil of the gun is not too much. (pay close attention to the amount of eye releaf you have on the scope or it will bite you)
My AK74s & my ARs with scopes can be bumped and hold tight enough to get 2 to 3 rounds bumped on a 10" gong at 300yds.
If everyone is thinking alike, then somebody isn't thinking.
George S. Patton