I recently watched a YouTube video on Garand Thumb’s channel that introduced the Army’s new advanced sniper rifle (ASR) – the MK22 ASR. The rifle is a special purpose Barrett MRAD rifle that includes three different barrels for the three cartridges selected for this rifle. Of course that got me wondering about how the three cartridges compare and that led me to writing this post.
In the video, Kevin Owens enumerates the three cartridges and their intended application. The first is the venerable and common .308 Winchester which was selected to allow folks to train with this rifle on virtually any base in the world. The second cartridge is the .300 Norma Magnum using the 215 grain Berger Hybrid bullet for anti-personnel (soft human) targets out to 1500 meters. The final cartridge intended for anti-material (hard target interdiction, or HTI) targets is the .338 Norma Magnum which is intended to replace the .50 BMG.
Finding published advertised ballistic data on the Norma Magnums has proved to be a little challenging. As such, I’ve had to mix and match data from different sources. Keep that in mind as you read on as I can’t guarantee precise accuracy of the ballistic data.
For the .308 Winchester cartridge, I’m going to use the ballistic data from a load that includes a 168 grain Berger Hybrid bullet. While I suspect the most likely cartridge to be used for training will be 7.62x51mm NATO (M80) cartridge, I think the load with the Berger Hybrid bullet will provide a better comparison against the .300 Norma Magnum. I may come back and update this later as I find more information about the cartridges.
|Advertised Ballistics||.308 Winchester||.300 Norma Magnum||.338 Norma Magnum|
|Bullet||168 grain Berger Hybrid||215 grain Berger Hybrid||300 grain Norma Match King|
|Ballistic coefficient||.489 (G1)|
|Muzzle velocity||2700 fps||3000 fps||2657 fps|
|Muzzle energy||2719 ft/lb||4296 ft/lb||4703 ft/lb|
I completely get SOCOM didn’t select these cartridges for hunting or other recreational activities. However, if I was going to consider picking up a rifle in one of the Norma Magnum cartridges I would do so with either hunting or long distance target shooting in mind. As such, my discussion of these cartridges will proceed along those lines.
From a hunting perspective, the advertised ballistic data confirms that all three cartridges have both the necessary sectional density (SD) and initial muzzle energy for both medium and large game hunting applications. The minimum SD for hunting medium game is .210. The minimum SD for hunting large game is .250.
While the initial muzzle energy of all three cartridges is sufficient for medium and large game hunting applications, the question that follows is how far out will the cartridges go before they no longer have sufficient energy for those applications? That distance will determine the cartridges effective range.
The following table compares the remaining of the projectiles at various distances:
|Energy||.308 Winchester||.300 Norma Magnum||.338 Norma Magnum|
|525 yards||1244 ft-lb||2567 ft-lb||2891 ft-lb|
|775 yards||824 ft-lb||1966 ft-lb||2251 ft-lb|
|1200 yards||1210 ft-lb||1442 ft-lb|
|1375 yards||985 ft-lb||1202 ft-lb|
|1550 yards||807 ft-lb||1021 ft-lb|
|1825 yards||804 ft-lb|
I purposely selected the distances in the energy table to only include those at which a cartridge reached its effective distance.
The data indicates that at 550 yards the .308 Winchester has enough remaining energy to still be effective for large game, but that’s about its limit. At this distance, the Norma Magnums still have plenty of oomph left for large game.
The .308 Winchester can be stretched out to about 775 yards effectively for medium game applications. Again, the Norma Magnums are still effective for large game at this distance and continue to be for quite a bit more further.
The .300 Norma Magnum remains effective for large game applications all the way out to the 1200 yard mark. At this distance, the .308 Winchester is completely out of the game and the .338 Norma Magnum is still going strong for the same application. In fact, the .338 Norma Magnum continues to carry enough energy for hunting large game out to 1375 yards.
The .300 Norma Magnum maxes out its effective range for medium game at 1550 yards. The .338 Norma Magnum keeps its medium game effectiveness up until the 1825 yard mark.
A word of caution. I am fairly certain the Norma Match King projectile on the .338 Norma Magnum is not designed for hunting applications. As such, I would suggest that those thinking about taking the plunge and picking up a rifle chambered for the .338 Norma Magnum to do so with long distance shooting as the primary application.
The effective distance of both the Norma Magnums is impressive. The idea of attempting to hit a vital zone target at over 1200 yards seems ridiculous to me. However, that is probably because I simply don’t have confidence in my current skill level to take that kind of shot – at least not at a game animal. That said I am now very curious how long the projectiles for these cartridges remain supersonic which will be the limiting factor for both hunting and long distance target shooting applications. The next table explores this.
|Velocity||.308 Winchester||.300 Norma Magnum||.338 Norma Magnum|
|1025 yards||1218 fps||1763 fps||1614 fps|
|1600 yards||1265 fps||1204 fps|
|1700 yards||1200 fps|
The more I look at these ballistics, the more I am intrigued by the .300 Norma Magnum for both hunting and long distance target shooting applications. It seems to me that the .300 Norma Magnum can outperform the 6.5mm Creedmoor and the .338 Lapua Magnum that are my go to cartridges for hunting and long distance shooting applications respectively. The only drawback to the .300 Norma Magnum is the lack of rifle manufacturer support and ammunition availability at the moment. Time will tell if the .300 Norma Magnum will gain market support.
In summary, the velocity data indicates the .308 Winchester, the .300 Norma Magnum, and the .338 Norma Magnum will remain supersonic out to 1025, 1700, and 1600 yards respectively.
Okay. That’s cool. But what about drop and drift?
|Drop||.308 Winchester||.300 Winchester Magnum||.338 Winchester Magnum|
I’m not going to spend too much time on the drop data in this comparison. However, I will say that these data points are consistent with what I’ve learned about bullet drop. Drop is a result of exposure to gravity. Slower moving projectiles experience more drop at a given distance because they take longer to arrive at that distance and are therefore exposed to gravity longer. The idea of “the faster the bullet the flatter the trajectory” generally holds true especially when comparing projectiles based on the same design.
One other important takeaway from this data is that hunting at extended distances will require better optics than hunting at shorter distances. I’m not just talking about magnification, albeit magnification helps. I’m talking about the range of mechanical adjustment. For example, the .308 Winchester at 1025 yards will require a mechanical adjustment of 38.1 MOA (11.1 MRAD) based on a 100 yard zero. The .300 Norma Magnum at 1700 yards will require an adjustment of 58.4 MOA (17 MRAD). The .338 Norma Magnum at 1600 yards will require an adjustment of 63.6 MOA (18.5 MRAD). To the best of my knowledge the amount of adjustment needed for the Norma Magnums exceeds the adjustment range of even the highest quality optics on the market. As such, these cartridges will need an offset scope base to compensate for the mechanical limitations of the optics to enable the shooter to stretch out to those extended distances. The longer the effective range, the higher quality optics needed.
Let’s look at wind drift.
|Drift||.308 Winchester||.300 Winchester Magnum||.338 Winchester Magnum|
The wind drift data is also consistent with results from other comparisons I’ve done. Again, generally speaking the higher the BC the less the projectile is susceptible to drift.
From a hunting application perspective, this data is a stark reminder of the importance of being able to estimate wind accurately. Even at 525 yards, a bad wind call can mean completely missing the vital zone with any of these cartridges. At best, this means tracking a wounded animal. At worst, this means a complete miss. The same holds true for a bad distance call, but as I’ve said before wind calls are more art where distance calls are more science given proper supporting equipment.
One other thing comes to mind here and that’s the importance of knowing the ballistic data from one’s selected hunting cartridge load from one’s own rifle. The ballistic data I was able to find on these cartridges did not include any information related to the barrel used for testing. As such, there is a good chance the actual applied ballistics will be different from what I have published here. This will be very important when stretching out these cartridges at extended distances. I highly recommend getting a chronograph and gathering actual ballistic data before applying this data in the field.
After writing all of this and as I stated previously, I am very intrigued by the .300 Norma Magnum and hope to see market interest around this cartridge grow in the future. I still hold a healthy curiosity for the .338 Norma Magnum. However, while the .338 Norma Magnum ballistics are definitely impressive I didn’t find them quite as intriguing as the ballistics from the .300 Norma Magnum. At any rate, I’m not going to drop everything and go pick up a new rifle at this moment. Rather, I’m going to employ a wait and see strategy.