Airborne -- You shouldn't need new chokes and if you want to cut cost stop purchasing Black Cloud or Blind Side or other designer loads, don't get caught up in the hype from the ammo companies. Get some normal round or almost round (Xpert) loads and shoot some patterns with your Mod choke to see which will give you good patterns at the distance you shoot your birds. If you shoot a variety of ducks then a #3 steel load should work good for you on decoying birds.
While load and choke are important to killing birds, if you really want to reduce your bird-to-shell ratio then get your birds close and work on your wing shooting skills. For starters, go start shooting skeet with a low gun. Remember, if you can't put the pattern on the front end of the duck then little else matters.
Here is a link to a patterning article that might be helpful.http://www.wildlifedepartment.com/hunti ... erning.htm
And, here's a table that will help you select the right load/pellet size/pattern density for your birds.http://www.wildlifedepartment.com/hunti ... yTable.pdf
Here are some pattern numbers of mine that will give you an idea of what you might get from a Mod choke with some of the loads you shot and others you should try.
Pattern results from a 12-gauge 3" Remington 870 Special Purpose with a 28" barrel and factory flush Rem-chokes (pattern average of five, 30" post-shot scribed circle, yardage taped muzzle to target, in-shell pellet count average of five, and true choke constriction from bore gauge).
12 GA 3" FEDERAL PREMIUM BLACK CLOUD FLIGHT-STOPPER STEEL LOAD
1 1/4 oz #2 steel (91 regular zinc plated steel pellets + 53 FS steel pellets = 144 pellets) @ 1,450 fps
40 YARDS -- Mod (.018" const.) / pattern 92 (64%)
12 GA 3" WINCHESTER ELITE BLIND SIDE STEEL LOAD
1 3/8 oz #2 Hex Steel (176 pellets) @ 1,400 fps
40 YARDS -- Mod (.018" const.) / pattern 104 (59%)
12 GA 3" WINCHESTER XPERT HI-VELOCITY STEEL LOAD
1 1/4 oz #2 steel (146 pellets) @ 1,400 fps
40 YARDS -- Mod (.018" const.) / pattern 106 (73%)
12 GA 3" FEDERAL SPEED-SHOK STEEL LOAD
1 1/4 oz #2 steel (154 pellets) @ 1,400 fps
40 YARDS -- Mod (.018" const.) / pattern 115 (75%)
12 GA 3" REMINGTON SPORTSMAN HI-SPEED STEEL LOAD
1 1/4 oz #2 steel (152 pellets) 1,400 fps
40 YARDS -- Mod (.018" const.) / pattern 110 (72%)
Thanks for your service. Good luck.