Q: How does the .270 Winchester stack up against the .270 WSM? Is there really all that much difference in velocity and hitting power? Does the .270 WSM offer enough of an advantage for me to trade my old Model 700 in on one?
A: I’ve compared the maximum velocities of the two cartridges as shown in various reloading manuals and it appears that the .270 WSM has about a 150 fps velocity advantage over the venerable .270 Winchester when both are fired in barrels of the same length. Surprisingly Hornady’s 130gn GMX Superformance loading factory data, has the Superformance load for the standard .270 driving the 130gn GMX bullet at 3190fps outrunning the fastest .270 WSM 130gn GMX loading by 40fps. I can get 3230fps with the 130gn InterBond in my .270 WSM which means that Hornady should be able to equal that with a Superformance load for the .270 WSM. My calculations indicate recoil in similar weight rifles at 18.5 ft/lbs for the 270 WSM and 15.75 ft/lb for the .270 Winchester when both are loaded to top speeds with a 130gn bullet. There isn’t much difference in the trajectory of their bullets. At 400 yards the .270 WSM has 4 inches less drop while at 300 both shoot flat enough to for a dead-on hold when sighted in 3 inches high at 100 yards. In all honesty, you could use them both in the field and never notice any difference between their performance.