Closed feed calls usually take less air to use, big deal? I suffered from asthma until I retired, still have some problems but not bad. It was easier to use a close reed call without going into a coughing fit. Down side to a close reed as they are usually metal reeds in them and in cold weather they freeze up and I had to keep a few on lanyards keep them inside my coat and rotate them as they froze.
Open reed calls usually take more air but are more versatile as to getting more varied sounds and some even make decent howls, plus their reeds are plastic, more open and less prone to freezing.
Most people that use mouth calls have whole drawer full of them, I do. We keep trying different ones untill we find ones that are easiest to make the sounds we want.
I usually keep close reed calls in my e-caller bags as back ups as they are less prone to damage getting jammed between the equipment there. I have open reeds around my neck.
I like open reeds from Carver and TT. Close reeds from RR and Sceery. Plus a Sceery bite call.
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After the first shot the rest are just noise.
Make mine a Minaska.
Heaven has rules and walls, He-l has open borders