I use my Rockchucker for rifle ammo, including .44 Magnum. I shoot too few of the .44s to warrant setting up the caliber on my Dillon 550B.

However, When using the Rockchucker, I prefer the Lee Auto-prime for priming which attaches to the die holder atop the Rockchucker. Seating primers with a stock Rockchucker is perhaps its only design flaw.