7mm PRC vs .300 PRC
A to-scale size comparison of the 7mm PRC and the .300 PRC, drawn from SAAMI and C.I.P. cartridge dimensions and aligned at the case head.
7mm PRC (left) beside .300 PRC (right), shown at the same scale.
The 7mm PRC has an overall length of about 3.34″ with a 0.284″ bullet. The .300 PRC runs about 3.70″ on a 0.308″ bullet. That makes the .300 PRC about 1.1x the overall length of the 7mm PRC. See the full reference for each: 7mm PRC and .300 PRC.