The pre-war Beretta Model 38A was a magnificent SMG, but it included a fair number of fancy elements that would prove to costly to justify once wartime production needs grew. Beretta would simplify the design progressively over the course of the war. What we have today is a Model 38/42 with a much simpler fixed-firing-pin bolt and a smooth barrel without jacket.
Is the 38/42 as nice to use as the original 38A? In my opinion, no – but it’s pretty close. The Beretta 38 family in all its iterations are excellent guns.