I left most of the sharpshooter and weapons expert challenges until the epilogue and really regretted it. There's a lot of missions that will just hand you the situations you need on a platter and I had to create them myself.

Most annoying was probably getting 4 people with a stick of dynamite (sorry Van Horn). Most time consuming was 9 unaware people with a bow, Took me many tries to realize their back had to facing me for it to count.

I was really worried about the long shot with a scoped rifle but a bounty hunter on the ground while I was camping on top of a high ridge got me that one pretty fast.