I too shoot mostly cast through mine. I favor the Lee 160gr Semi pointed gaschecked bullet. I have a 6-cavity mold and use 20gr of #2400. I have taped my mold with aluminum tape to expand bullets cast to .315” and size to .314”. Using BLC2 powder and the PPU 180gr semi pointed softpoint bullet, you can approach.308win velocities. However, even at original 2,400fps, it’s not tossing “nerf” balls. My #4mk1 is one of my favorite rifles. BTW; that FTR 1953 means that your rifle was factory reworked with possibly a new barrel and refinished. My #4Mk1 was also FTR and sports a new barrel. It’s a tack driver with good ammo (ie: PPU). But, mine is all original!