The best for hides is a 12 gauge. A properly choked and patterned shotgun with lead BB or better yet TSS #2's is a killer that the fur buyer or taxidermy guy can't complain about.
I just ordered some Hevi-Shot Tungsten #2 and a Turkey (extra full) extended choke in 20 gauge. The options in this area for 20 are much more limited than 12 and I think I did the best I could. Turkey chokes are usually designed and tested for smaller size shot. I'll just have to see how it patterns with the #2. My intention is bobcat, and red and grey fox. No coyote. 20 ga because it's what I have and prefer for quail and chukar.
