While looking for a close range destroyer, I came across the No Excuses bullet line. Bought the 600 and 500 grain in .503 for a Knight Bighorn. Dave sells them in various sizes and offers variety packs.
The 600 grain stabilizes very well and hits HARD! Recoil is no joke but the Knight is well built and makes recoil management fine. Bullet is easy to start but snug in the rifling. 80 grains volume/63 by weight of Triple Se7en 3FG and a #11 cap was the clear winner for accuracy and repeatability.