.308 Winchester vs .300 Winchester Magnum
A to-scale size comparison of the .308 Winchester and the .300 Winchester Magnum, drawn from SAAMI and C.I.P. cartridge dimensions and aligned at the case head.
.308 Winchester (left) beside .300 Winchester 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 Winchester Magnum runs about 3.34″ on a 0.309″ bullet. That makes the .300 Winchester Magnum about 1.2x the overall length of the .308 Winchester. See the full reference for each: .308 Winchester and .300 Winchester Magnum.