I've shot a lot of doves on big fields and I can tell you from experience that 50 is not near enough guns on a 100 acre field. Figure it like this. Let's say the field is 2000ft x 2200 ft which is 101 acres and basically square. If you space your shooters out on just the perimeter with a generous 60-65yd spacing between shooters, you've got 43 stand locations to adequately cover just the perimeter/outline of the field with nobody in the actual field itself. You'll need to scatter another 60 or so guns (at a minimum) out in the field itself (this is where the majority of your acreage is) to keep the birds in the air and moving. If it is a "true" 100 acre field, you should not have any problem whatsoever with 100+ guns/stands on it.