I have a Mossberg 835 turkey gun. I tried to pattern it but the factory sights ran out of adjustment while still shooting 6" high at 40 yards. I took them off and got a TruGlo Gobble Dot. It has a red front and green rear but isn't adjustable. Would I be better off using just the red front or the unadjustable front and rear. It's my only shotgun so will get used for waterfowl and small game too. Any help would be greatly appreciated! Thanks!