History of the 300 WSM caliber
The 300 Winchester Short Magnum (WSM) caliber was introduced in 2001, created by Winchester as part of its Short Magnum line of cartridges. The idea behind this caliber family was to offer performance close to or equal to that of traditional (belted) magnum calibers, but in a compact and powder-efficient format. The 300 WSM, being one of the most popular in this series, quickly caught the attention of shooters and hunters alike due to its long-range performance and innovative design.
The design of the WSM (270WSM, 7mmWSM, 300 WSM) is based on a shortened, beltless case with a pronounced 35-degree shoulder. This choice allows for better efficiency in terms of powder combustion, in fact the performance of the 300 WSM is similar to that of a 300WM while burning 15% less powder. This modern approach offers ballistics comparable to the 300WM in a more ergonomic format, a better barrel life and above all a better regularity of velocities thanks to a shorter powder column and better powder combustion.
From its introduction, the 300 WSM was adopted by big game hunters and competitive shooters who sought a high-performance magnum cartridge in short-action rifles. Its design not only reduced felt recoil, but also reduced the length and weight of the rifle, while maximizing barrel life, making it ideal for a variety of uses ranging from mountain hunting to long-range competitions.
Technical characteristics of the 300 WSM
The dimensions and technical specifications of the 300 WSM illustrate its optimization for modern performance:
- Base Diameter : 0.535 inch (13.59 mm)
- Case Length : 2.100 inches (53.34 mm)
- Overall Length : 2.860 inches (72.64 mm)
- Collar Diameter : 0.343 inch (8.71 mm)
- Shoulder angle : 35 degrees
- No Rifling : Typically 1:10 inch (254mm), optimized to stabilize projectiles between 150 and 230 grains.
The 300 WSM is capable of propelling heavy projectiles at high velocities, thanks to an efficient internal volume for the powder, coupled with high operating pressures 65,000 psi (4,482 bar).
Comparing the 300WSM with other similar calibers
The 300 WSM sits in a very competitive category, where it is often compared to calibers like the 300 Winchester Magnum (300 WM) and the 300 Precision Rifle Cartridge (300 PRC). Here is a detailed analysis:
|
Features |
300 WSM |
300 WM |
300 PRC |
|
Case volume (water grains) |
80-82 |
93-95 |
105-107 |
|
Typical speed (200 gr ELD-X) |
2820fps (860m/s) |
2860 fps (870m/s) |
2920 fps (890m/s) |
|
Total length |
2,860 inches |
3.34 inches |
3.70 inches |
|
Shoulder angle |
35 degrees |
25 degrees |
30 degrees |
The 300 WSM offers a slight reduction in speed compared to the 300 WM and 300 PRC, but this difference is largely compensated by its powder-efficient design, of the order of 15% and a better combustion regularity allowing to have generally lower SD and ES than in 300WM and 300 PRC. The 300 WSM offers impressive performances for such a compact format!
Commercially available 300 WSM ammunition:
The 300 WSM caliber is available from a few ammunition manufacturers, Hornady, Norma, Winchester are the main ones. RWS has recently cut its reference on this caliber.
| Reference | Projectile weight | Output speed | Brand | Price (€) |
| Winchester Power-Point | 180 gr (11.66 g) | 910 m/s | Winchester | 70 € (box of 20) |
| Hornady Precision Hunter ELD-X | 200 gr (13.0 g) | 860 m/s | Hornady | 100€ (box of 20) |
| Norma Bondstrike | 180 gr (11.7 g) | 940 m/s | Norma | 125€ (box of 20) |
| Norma Tipstrike | 170 gr (11 g) | 975 m/s | Norma | 110 € (box of 20) |
| Hornady Outfitter GMX | 180 gr (11.66 g) | 883 m/s | Hornady | 90 € (box of 20) |
These ammunitions are mainly geared towards big game hunting, there is no loading geared towards long-distance shooting and target or gong shooting. For this, it will be necessary to reload and it is in this situation that the 300 WSM becomes an incredible caliber!
Reloading the 300 WSM caliber:
The 300 WSM gets its maximum performance from reloaded ammunition.
In effect, you eliminate the main limiting factor of the 300 WSM: its lack of manufactured ammunition references.
For a long time, the only quality cases available were the 300 WSM, but with a recent gain in popularity, Lapua has been offering 300 WSM cases since 2024!
We have a lot of experience with reloading the 300 WSM, we have tested many combinations, but the ones that have stood out the most in our custom are the following:
- 220 gr Lapua scenar L powered by a N160 charge with a speed of 870 m/s. Incredible accuracy at 600 meters (less than 10 cm on 15 shots)
- 208 gr ELD-M from Hornady propelled by a charge of N165 at a velocity of 890 m/s. A very high-performance load, soft on the barrel and recoil with impressive performance for a single base loading!
- 225 gr ELD-M from Hornady propelled by a heavy charge of N565 at a speed of 910 m/s… A charge that rivals the ballistics of a 338LM but is restrictive on the life of the cases and the tube…
In short, the 300 WSM is an absolutely incredible caliber to reload, by far our favorite in the editorial department!!
We now find many 300 WSMs on Fclass firing ranges in the United States, with splendid weapons like this one: Their specificity?
a long chambering which boosts the performance of the 300 WSM by releasing powder volume
What use should you consider the 300 WSM for?
The 300 WSM will be perfectly suited for two types of users:
- The experienced hunter wanting the performance of a large magnum in a smaller format in order to keep the weapon in a more compact format (short action + short 22” or 24” barrel); Typical of mountain hunters
- For long-range reloading shooters, this caliber is absolutely fantastic in experienced hands both at the reloading bench and on the firing line. Well loaded, you will have nothing to envy from .338 LM… All while costing 2 times less and with 40% less recoil!
To conclude on the 300 WSM caliber:
Want to go further? Go to this video where we compare the ballistics of the 300 WSM with other calibers common in the TLD world!