I got this from packing.org
You might be able to carry a handgun with this permit while trapping.
Notice it says " while engaged in that activity........"
BE CAREFUL, don't take my word for it.
I am not an expert and just got this from the internet.
Read the actual laws yourself.
Here it is:
Special Sports Permit for Hunting or Fishing From County Treasurer's Offices--
A sportsman's firearms PERMIT allows one who holds a fishing, hunting, trapping, or dog-training license to carry a handgun while engaged in that activity, or moving to and from that activity (but not loaded in a motor vehicle). To obtain one, apply to the county Treasurer (not Sheriff) and bring your hunting or fishing etc. license. The cost is $6 for 5 years. The permit is issued IMMEDIATELY and WITHOUT any application process (other than to list one's name and address and description). One need not be a resident of Pennsylvania to have a permit, but must have a Pennsylvania license for fishing, hunting, trapping, dog training. The Sportsman's permit is a good option for those who only want to have a handgun while hunting or fishing. It's very easy to obtain, at a reasonable cost, and it's issued immediately.
Good luck.
PC