300 WM 190gr Ammo Comparison Test

Table of Contents

• Introduction and Test Procedures
• The Test Rifles
• Test Results
• Conclusion and Thoughts

Introduction and Test Procedures

We have done a number of match ammo comparison tests involving different calibers including various .308 loads, 260 Remington and even 7.62 NATO M80 ball ammo. But we figured it was now time to step up into the bigger calibers for those that are shooting long range rifles and are looking for different ammo that might fit the bill for 1-mile shooting. If you are not familiar with the .300 Win Mag and its history with Sniping, be sure to take a look at our article on the sniping history of the .300 Win Mag now.

For the first phase of our .300 Win Mag match ammo reviews we wanted to focus on the original A191 class of ammo, or ammunition around 190gr. This is still the most common class of ammo being used for the .300 Win Mag and it still has a lot of capability. Our next phases of testing will be with the heavier and more capable 200+ grain ammo. Even with the lighter bullets of the A191 ammo, the 300 Win Mag is still able to stretch out for the 1-Mile shots (1609 meters). Kris Kyle, the SEAL sniper with the highest kill count for an American Sniper, primarily shot a .300 Win Mag and this is also the cartridge of choice for both the US Army and USMC for their current primary long range sniper rifles.

With this particular test, one thing we had to be careful with is that the .300 Win Mag is more punishing to the shooter and barrels so we wanted to take our time to try and spread out the shooting a bit more than our smaller cartridge tests. Barrels also heat up very quickly which makes fighting heat mirage coming off the barrels a much more difficult task. Because of these reasons, we elected to keep the number of different loads tested in each phase smaller, limiting it to only five different types of ammo per phase.

We also want to point out that it typically is more difficult to make a .300 Win Mag rifle extremely accurate due to the headspacing being done off of the belted case head and not the shoulder. Because of this we were interested to see just what kind of accuracy performance we would see from our test rifles and how they performed. We still expected to see .5 MOA for our custom rifle and sub 1 MOA for our factory rifle.

The test procedure is not unlike our others and is as follows:

• 1 Box of 20 rounds of ammunition will be purchased over the counter/web/mail order to insure randomness. No factory provided ammo for testing
• 3 groups of 3 rounds will be fired from each of the two rifles at 100 yards
• Called flyers will be noted in the results but no individual groups will be re-fired
• Each rifle will have a bore snake pulled through the bore ONCE before the start of the test of each ammo type.
• Each rifle will have a single dry patch ran through the bore after the bore snake.
• Each rifle will fire 1 fouler shot after the bore snake cleaning and before firing the groups for record
• Groups are fired with a Caldwell sand bag up front and a sand sock under the rear of the rifle
• Groups are fired slow fire at what ever pace the shooter desires.
• Groups are fired with a scope set on 16x (read about the rifles to see what makes & models of scopes were used for the test)
• All rounds are fired through a chronograph set 10 feet from the muzzle to measure average velocity, standard deviation, and extreme spread.
• Outside temperature is recorded for each series of tests as well as wind conditions
• Retesting is allowed but the entire test must be fired as a whole for that specific ammo

We will be adding more results to this page as we conduct additional rounds of testing of various .300 Win Mag ammo.

The Test Rifles

For our ammunition comparison tests we always use two different rifles of different quality to try and get a good understand and comparison of performance with the ammo. We like to use different length barrels and twist rates if possible and usually want one of the rifles with, and one without, a muzzlebrake. For this test, one rifle has a muzzlebrake and the other we fired with a suppressor attached.

The first rifle for our test was one we recently reviewed, the Ruger M77 Hawkeye Long Range Target. This rifle performed well in our normal battery of tests and met the criteria we wanted for a test rifle. Some of the features include a 26″ (660mm) long heavy barrel with a 1:9″ twist, which is a bit faster than is standard for a .300 Win Mag rifle. The rifle also has an effective muzzlebrake to help control the recoil. The stock is an epoxy covered laminated wood stock with a nice tactical shape and also features a detachable box magazine. The stock is adjustable for length of pull and the cheekrest is adjustable. The scope we mounted is a Burris Veracity 5-25x50mm scope that performed decently in our testing, though lacked a few features we prefer on tactical scopes. For our testing here, it would work fine. During our testing of this rifle, it averaged about 1 MOA with the different ammo types we tested, which is what we were looking for.

For the second rifle we like to use a very high end custom built rifle to provide a rifle from the upper side of the segment. We elected to go with one we have had for about a decade now, the Tactical Operations Alpha-66. This rifle is intended to be used with a suppressor for much of its duty and has a shorter 24″ (610mm) very heavy profile barrel with the typical 1:10″ twist. This rifle actually comes with a .25 MOA accuracy guarantee and we have seen those size groups with this rifle, but the shooter has to be on top of his or her game to get those results. Additionally, this rifle has a unique chamber that is cut with Tac Ops own custom made reamer and back when it was built, the 220gr craze had not taken off. The reamer, and chamber, was tailored for the 190gr bullets. This lead to a problem during our testing which will be described below. The rifle is topped with a Nightforce NXS 5.5-22x50mm scope that came with a A191 BDC and 1 MOA elevation clicks, a feature no longer offered by Nightforce. All of the ammo tests fired with the Alpha were fired with the TacOps suppressor attached.

We figured that these two rifles would give an excellent sampling of what could be expected from a wide spectrum of bolt action rifles. A lower priced factory rifle and a very top of the line custom built rifle.

Test Results

This initial test included five different loads from four manufacturers of match quality A191 class ammunition. These included the Federal Gold Medal Match 190gr, Ruag Swiss-P Target 200gr, HSM Match 190gr), HSM D46 185gr, and Black Hills Match 190gr. The summary of the results are included in the tables below, but be sure to visit each manufacturers result page to find out more specific details on how the ammo performed as well as photos of the ammo, photos of the best group, price, and other results from the test.

Conclusion and Thoughts

After all of the shooting was completed and the results tabulated, there were a few things that became obvious. One, you will notice the line of zeros for the RUAG ammo out of the Alpha-66. This was because that particular bullet would not chamber in the rifle. This is not a fault of RUAG but rather the delicate chamber cut on the Alpha-66 and how it was setup specifically for the 190gr Sierra Match King bullet. We talked to Tactical Operations about this and they now build their .300 Win Mag rifles with a little bit of leeway added in to the headspacing for the popular 215-220gr bullets in use today. It was unfortunate because the standard deviations routinely are excellent from the RUAG ammo and we wanted to see how it would perform out of the Alpha. It did not shoot very well from the Ruger. For whatever reason, the Alpha will chamber the Sierra Matchking 220gr bullets as well as the Berger Hybrid 215gr bullets without problem, but not the 200gr that RUAG uses. 

Another interesting note is just how sensitive the .300 Win Mag is to tight chambers. Notice how much higher the velocities are out of the Alpha with a 2″ shorter barrel than the Ruger. The Alpha was also fired with a suppressor, but that would not effect the velocities like that. We have routinely seen increased velocities from custom built rifles and it is attributed to a tightly cut chamber and everything just having tighter tolerances. It is especially pronounced with the .300 Win Mag. Given the extra performance from all of the ammo out of the Alpha, this really will translate well for long range shooting, some loads are a full 100+ fps faster. 

As expected, the Alpha shot all of the ammo, except for the unique D46, better than the Ruger. That Lapua D46 bullet is a stepped boattail design with a very high BC for its weight, but the construction is more difficult and it seems it doesn’t quite match the accuracy of a traditional HPBT match bullet design. This is likely due to that more difficult construction process. But this load is certainly still capable enough and with the velocities that HSM gets with it, it translates into an excellent long range load, even surpassing the 220gr ammo performance at long range. 

None of the ammo tested (so far) was an exceptional performer, but as we mentioned at the start of this writeup, it is more difficult to get exceptional accuracy out of a .300 Win Mag rifle. Then add in how muc we were fighting mirage from heated barrels, shooter fatigue from the bigger recoil and blast, and with scopes only set to 16x, the results are typical to what might be seen in combat or duty type of scenarios. The HSM 190gr load seems to be the standout in this first phase of testing as it shot very well from both rifles and it has a bit of extra velocity as well. This makes for a very good combination for long range shooting. Of course, the Federal and Black Hills ammo were also solid performers, but we cannot explain the high SD and ES of the Federal ammo this time around, that is very non typical for Gold Medal Match. 

With Phase 1 of the testing done, we’ll move on to some heavier weight loads next and then followup with Phase 3 with some other 190gr loads we didn’t get to this time. The results have provided some good insight and continues to illustrate that as the rifles capabilities and power goes up, so does the difficulty achieving consistency and magnifying performance.