Franchise has great words of wisdom on the Seirra fp bullets.
I have used seirra 300 grain fp bullets in a 44 mag at max velocities and have never recovered one. the animals died quickly if not dropping on the spot. I have shot numerous deer and several black bears with them. I know it is not the same caliber but it is a testimony for the bullet design.
the only Sierra FP bullet I have recovered was from a 375 win shot out of a contender this last year. 125 yard shot on a deer shot stem to stern (front point of shoulder to rear hip with over 36" of penetration and the bullet only shed 2 grains of weight. I have not shot swifts but have shot speer deep curls and like what they do. There are alot of guys with more experience than me on this forum. just my 2 cents worth. Good luck on your bullet testing and keep us posted!