Kevin,That's kind of strange that even after you replaced the caps it's still not going off. Without seeing I have no idea what would cause that.
Have you tried the hotter Remington caps that are out now? Don't know why it would just stop going off because fire on powder is fire on powder unless somthing is blocked or the flame is being kept a way by some built up crud or or something. Let me know what you find out.
That shotgun sounds like a good turkey gun! Mike