Ah yes the infamous Johnny Gun,

I have read extensively of its use by the Devils Brigade (FSSF)...and though they only had about 120 which they traded for with USMC for some explosives.

The Forcemen seemed to like it quite a bit.

Are there any former Jarheads who can give me some impression of how the Marines liked/used it?

Forcemen used it along side the BAR and .30 cal as fire support and were quite fond of its selective fire, rate of fire and magazine capacity.

Im probally remembering wrong but I believe it had a ROF of either 300 rpm or 900 rpm depending on which ROF was selected.

I have few "in action" shots from the FSSF that I can add later.

Though I also recall of one of the forcemen (on Anzio beach) talking about firing his Johnny Gun so much that the barrel had expanded to the point that the rounds he was firing were basically being pushed out...not fired out. So the rounds were falling about 15-25 feet from where he was firing from...funny...kinda...fortunately he also found a .30 cal so he was able to hold off the German attack..but it was a close thing.