.308 Winchester vs .300 Remington Ultra Magnum
A to-scale size comparison of the .308 Winchester and the .300 Remington Ultra Magnum, drawn from SAAMI and C.I.P. cartridge dimensions and aligned at the case head.
.308 Winchester (left) beside .300 Remington Ultra Magnum (right), shown at the same scale.
The .308 Winchester has an overall length of about 2.81″ with a 0.309″ bullet. The .300 Remington Ultra Magnum runs about 3.60″ on a 0.309″ bullet. That makes the .300 Remington Ultra Magnum about 1.3x the overall length of the .308 Winchester. See the full reference for each: .308 Winchester and .300 Remington Ultra Magnum.