I know production diaphragms are hit or miss. Mostly miss.
Years back, I got a diaphragm from a big-name company. It was freakin' awesome !!! Killed every bird that year with that call.
So, my Mrs found me a 3-pack of the same call. When those calls arrived, it was a matter of 10 minutes or less that thsy were ALL 3 in the kitchen garbage can. Junk from brand new.
Bought a call from a guy named Gooserbat. Been a user ever since. The calls last. And one bought this year sounds the same as one bought 5 years ago. Quality control. CONSISTENCY.