It has the same head and tube base diameter as a .338 Lapua magnum, but with less taper in the body. .33 XC also has a steeper shoulder angle and is longer than a .338 LM, holding quite a bit more powder. It is even taller than a CheyTac.
The concept of the .33 XC was developed by David Tubb, a long-time dominant force in the long-distance, competitive shooting community. He is also the designer of the 6 XC caliber. Tubb turned his attention to Extreme Long Range shooting, and the ELR community. He designed the .33 XC for shooters who have the gear to load and shoot .338 Lapua, who want to reach out farther. With a chamber reamer from Tubb a .338 Lapua Mag owner can have their gun rechambered for the .33 XC and turn it into an ELR gun.
Peterson Cartridge is a US rifle casing manufacturer with a strong reputation in ELR circles. Peterson brass is used in winning the King-of-2-Mile competitions – first in 2017 and also at the first KO2M France. Peterson brass was used in the win of the Nightforce Challenge. Peterson brass figures prominently in ELR Central competitions. Many shooters attempting new world-record, long-distance shots use Peterson casings.
Because of this, Tubb contacted Derek Peterson president and head calibre developer at Peterson Cartridge to design the tool pack to make the new .33 XC.
Peterson has successfully developed about two dozen different caliber tool packs across the last few years but the 33 XC was one of the largest.
Warning: Only use Peterson Cartridge Co. casings in firearms in good condition, designed, marked, and chambered for this cartridge. Do not use Peterson Cartridge Co casings for “fire forming” or any other purpose other than what they were designed and tested for. Peterson retains no responsibility for the enclosed casings if they are used outside of the manufacturer’s recommendations.