308 Match Ammo Comparison – 175gr

Table of Contents

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

Introduction and Test Procedures

We have now conducted several different match ammo comparisons for the 308 Winchester 168gr ammo and even the 260 Remington, but we have needed to do the more common long range 308 loads with 175gr class bullets. Over the past while we have been collecting a wide range of available factory loaded 175gr ammo and it finally was time to begin the the testing process with the first round of loads. We have so many different loads available that we will need to do several iterations to get through them all, but you’ll be able to follow all the tests on this page.

The test was to be conducted just like the 308 168gr and 260 match ammo comparison tests we have already done so we knew the general procedure that had worked well for us in those tests. To reiterate the goals from the original 308 test, the goal was to take out as many of the variables as possible that would influence the results, but there was a need to keep it simple without a ton of rounds being fired or complex mechanisms like a rifle vise. Without a serious vise, we recognize that there will be shooter error, but we use a sand bag and sand sock to help stabilize the rifles. We also use two rifles that are a permanent part of Sniper Central and the same two rifles will always be used for future tests for this review. More info on the rifles is provided later in this article. Here are the details of the actual test procedure for each make of ammunition:

• 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 to prevent “ringers”
• 3 groups of 3 rounds will be fired from each rifle 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.
• 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 whatever pace the shooter desires.
• Groups are fired with a scope set on 14x (read about the rifles to see what makes & models of scope are currently being used)
• All rounds are fired through a chronograph 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 particular ammo

As you can see, there are not a lot of rounds fired for each make of ammo, but this was needed to keep the tests reasonable. Shooter error certainly comes into play and the results have both the raw averages as well as averages with the “called flyer” groups excluded. A called flyer has to be called before looking at the target again to see if it really was a flyer.

There is no doubt that the test has flaws, but it should provide a good overall impression of ammunition performance. The chronograph results are provided to give some true empirical data to examine, and not just some accuracy comparisons shot by a single shooter. For the 175gr ammo we wanted to use both a rifle with a faster rate of twist (1:10″ or 1:11″) as well as one with a standard 1:12″ as that is the more common twist rate for a 308 and some questions arise about using these heavier bullets in the slower 1:12″ twist rifles.

The Test Rifles

For the tests, we initially wanted to utilize a bolt action and a semi-auto sniper system (SASS), but we eventually decided against the SASS rifle due to the cleaning and maintenance logistics between ammo changes. To keep things simple we elected to go with two bolt action rifles, but we wanted two different types of rifles. What we eventually settled on was a custom built rifle and a high end factory built rifle.  We also wanted one to have a 1:12″ twist and one to have a faster rate of twist in order to address those shooters that have the common 1:12″ twist rifles. The two rifles we elected to use were a custom built Paladin rifle by Snow Mountain Rifles and a factory FNH SPR A3G. The FN SPR is a higher end production rifle that was selected by the FBI as an approved alternative rifle to the custom built GAP rifles that their HRT and Regional SWAT snipers use. The FN uses a McMillan stock and normal high quality FNH chrome lined barrel and a Winchester M70 pre-64 style action with full control round feed (claw extractor). It also has a thick heavy barrel with flutes and typically are a long lasting, good performing rifle. The one we used for our tests here has a Leupold Mark 4 4.5-14x50mm scope with mildot reticle and M1 knobs mounted on top.

The second rifle we selected was the Snowy Mountain Rifles (SMR) Paladin that is built on their own custom action patterned after the Remington 700. They use benchmark barrels and in this case it has a 1:10″ twist, and a bedded and custom painted Bell & Carlson 2956 stock with full aluminum bedding block. This rifle consistently has shot sub .5 MOA and has been a solid performer for several years for us. For the these ammo tests we used a Zeiss Conquest 4.5-14x50mm scope with mildot reticle and target knobs.

Like most custom rifle builders, SMR guarantees .5 MOA accuracy and while FNH does not offer a guarantee, their rifles had to hold a high level of accuracy during the FBI trials and are typically expected to shoot about .5 MOA as well. If you read in our review of the rifle you will see where we really had to work at it to get that level of accuracy, but it can do it with the right load. The 1:12″ twist vs. 1:10″ is a question that many people ask and we wanted to include a 1:12″ here to insure that the heavier 175 class bullets can be shot from both without problems. Though the ultimate accuracy of the rifles comes down to the quality of the build and not the rate of twist. For this ammo test, we are comparing all of the ammo in both rifles in order to get a comparison of the ammo to other brands of ammo, and not one rifle versus another.

Test Results

The initial test included 7 manufacturers of match grade ammunition including HSM, NWD, Hornady, Federal, Eagle Eye, Blackhills and Fiocchi. There will be more added in several more phases of testing at later dates. The summary of the results is included in the table below, but be sure to visit each specific result page to find out more specific details on how the ammo performed as well as photos of the ammo, best groups fired, price, and other details.

Conclusion and Thoughts

So, after all of the shooting and note taking had been done, what conclusions can be drawn? As most all shooters know, rifles will favor a particular load for reasons that cannot always be explained and these tests further confirm that assumption. While we tried to take out as much of the human factor as we could, the rifle was not in a clamped down vise with a mechanical device pulling the trigger, and therefore the groups were subject to the shooter and his or her errors. The amount of human disruption during the firing process can be effected by many things, so there is always those concerns to be considered when looking at our accuracy tests.

With the above caveats being mentioned, there are a few things of note that we would like to mention. It does appear that a nice tight chamber and a high quality barrel on a custom built rifle does effect the performance of the ammunition as the velocity routinely was faster in the custom built SMR rifle versus the factory built FN SPR. Both rifles have the same 24″ long barrel, which should have keep the velocities close. The standard deviation did not seem to be effected as much, but there was still a slight improvement in the SMR versus the FN SPR rifle. The extreme spread, on the other hand, actually was nearly identical between the two rifles, but this would have little to do with the a nice tight chamber and more to do with the ammo. The observation of faster velocities and lower standard deviations was the same as we found on the 168gr Match ammo test which also used a custom rifle and a factory rifle as the two test beds.

Another item of note is that accuracy of the FN SPR rifle with its 1:12″ twist barrel did not seem to be effected by the heavier bullets. If you look at the performance of the 168gr bullets in the original FN SPR A3G  review you will notice that the accuracy with the 168gr loads was very similar to the 175gr results from that review as well as all the 175 and 178gr results from this test. We have always had good success shooting 175-178gr bullets in 1:12″ twist barrels all the way out past 1000 yards. Of course, if this is a route you plan to go, be sure to test the loads in your actual rifles out to your expected engagement ranges to insure they are performing as desired.

In regards to the actual ammunition performance and comparison, what were our findings with this first round of testing? The SMR rifle shot everything great, except for the Hornady Superformance, even though it had the best standard deviation. The rifle really liked the Northwest Defense ammo with some exceptional groups, but it only did middle of the pack on the FN SPR. The NWD ammo uses the Hornady bullets exclusively and they have a 178gr HPBT load that we are anxious to try out as it uses the same very high BC bullet that the Hornady Superformance uses. It has a BC of .530 which will give it a marked improvement at long ranges. We will also mention that if you need to really stretch your 308 rifle beyond the standard 1000 yards, the Hornady Superformance load with that same 178gr HPBT bullet is a really good way to accomplish this. The average velocity is well above 2700 fps and with that high BC, it will do very well, but your rifle will need to like it for it to be effective.

The HSM load was much hotter than the factory numbers said it should be and when I talked with HSM afterwards, they checked the lot number and indicated it was loaded back in 2008 and that is probably why. They were using different powder back then and the current loads are where they are supposed to be for velocity. We’ll probably have to re test it at some point and see. Otherwise, the accuracy was very good and velocity high… a good combo for long range shooting.

The Fiocchi ammo was a surprise performer and performed very well and near the top of the group in terms of accuracy, SD and ES, though it had the slowest velocity in the bunch. But when it comes to choosing between accuracy or velocity, we typically pick accuracy! The Eagle Eye ammo is a new comer to the market and their unique claim is that they make all their own components, which is good for supply chain issues. Their ammo had very good statistical numbers in terms of SD and extreme spreads and the accuracy was not bad. Their unique bullet shape is something we want to try out at long ranges to see how it holds up.

Like normal, we cannot definitively say one load is better than all the rest. But we can see some good patterns and at least have a good idea of which loads to try when choosing a load for a specific purpose. If you need the ultimate long range capability, that Hornady load is looking excellent. If you want great repeatable performance right at the factory published numbers, the NWD and Federal Gold Medal Match lead the pack. For extreme consistency, NWD and Fiochhi looked very well. If going for the ultimate accuracy, then try as many of the loads in your rifle that look promising and then see which one your rifle likes best.

Stay tuned for the next round of testing and if you would like to request a particular match grade ammo be tested and posted, or if you are a manufacturer and would like to request your ammo be tested, please feel free to email us.