What Is the Difference Between 300 WSM and 300 Win Mag?
The 300 Winchester Magnum has been around since the 1960’s and has been a favorite for military snipers, big game hunters, and benchrest shooters alike. It is truly in contention for the title of America’s Favorite Magnum Cartridge and is the gold standard by which all belted magnum cartridges are measured.
The 300 Winchester Short Magnum (WSM) is a relative newcomer to the shooting community being released in 2001. The 300 WSM embodies the ballistic advantages of the 300 Win Mag and crams them into a short action rifle.
The result is a lighter rifle with identical barrel length and extremely similar external ballistics. Having a shorter, more maneuverable rifle can be extremely handy when elk hunting in thick brush.
Both rifle cartridges are extremely accurate and can easily achieve MOA to sub-MOA level accuracy with match grade factory loads or properly tuned handloads.
Although both cartridges are excellent for hunting or target shooting, they are not without their disadvantages.
Some detractors of the 300 WSM will point to its rebated rim, claiming that this might inhibit the ability of the bolt to push the cartridge from the magazine into the chamber. The 300 WSM’s steep 35-degree shoulders also play a part in this critique, as some forum users theorize that the sharp angle might hinder smooth feeding into the chamber.
Although I will say that feeding a 300 WSM is not as smooth as the experience with other cartridges, I’ve yet to experience a jam.
For the 300 Winchester Magnum, most of the complaints center around the useless belt on the cartridge case. As you’ll learn later in the history of the 300 Win Mag, the belted case is an artifact from the parent 375 H&H Magnum case.
Early rifles used the belt for headspacing, which caused premature case stretching and thereby reduced the lifespan of the brass. If all you shoot is factory ammo and you aren’t into reloading, this is a non-issue. However, for handloaders it’s a serious problem as it means you will have to replace your 300 Win Mag brass more frequently.
Many 300 Win Mag rifles now have their chambers reamed to headspace off the case shoulders, which eliminates premature case stretching entirely.
The last strike against the 300 Win Mag is the painfully short case neck. Some long range target shooting gurus state that the 300 Win Mag’s neck is not long enough to securely hold the projectiles and maintain concentricity. In theory, this could cause the bullet to enter the rifling off-axis and affect point of impact for long distance shots.
However, based on the lack of complaints by military snipers who routinely shoot well past 1000 yards with a 300 Win Mag, I’m guessing this critique is more an online forum talking point as opposed to a real-world issue.
In the following sections, we will analyze the 300 WSM vs 300 Win Mag in detail so you can understand the differences between these two rifle cartridges.
The article discusses Sectional Density, Ballistic Coefficient, Trajectory, Reloading, Ballistics, and other aspects.
