RCBS Single Stage shell holders are built from hardened steel and designed to properly align the case with the reloading die in single-stage and turret presses. They're sized to fit specific case heads and capture 0.125 inch of the case head for proper SAAMI headspacing. This model is compatible with the following calibers: 22/6mm/7mm Bench Rest Rem; 22-250/6mm/260/280/7mm-08 Rem; 240 Wthby Mag; 243/6.5-284/270/284/308/358 Win; 25-06; 257 Roberts; 257 Roberts Improved; 6mm/6.5mm Creedmoor; 6.5mm-06; 6.5x47 Lapua; 6.5mmx57; 280 Ackley Improved; 7mmx57/7.65mmx53/8mmx57/9.3mmx62 Mauser; 7mmx64 Brenneke; 30 T/C; 30-06 Springfield; 300 Savage; 7.7mmx58 Japanese Arisaka; 8mm-06; 338 Fed; 338-06; 35 Whelen; 370 Sako Mag/9.3x66 Sako; 400 CorBon; 45 GAP; 45 ACP.