The key component in any shooting sport or engagement is not the weapon but the ammunition.  When selecting ammunition it is always dependant on what you intend to shoot and at what distance.  There are some major ammunition makers who produce some fantastic factory loaded ammunition but when selecting a company that can really do it all, you should look to Southwest Ammunition in Mesa AZ.  The small veteran owned business was founded in 2010 by 2 prior US Marines who specialize in making rifle ammunition.  Southwest ammunition has offerings in 5.56, .308Win, .300BLK, .300WSM, .300Win, .260Rem, .338Lapua, .45ACP, and 9mm Parabellum.  Southwest ammunition also offers reloading services for several calibers on top of their loaded ammunition.

For this review, I took 4 different .308 rifles and with the help of a MagnetoSpeed LLC chronograph, I compared all 4 against each other using multiple loads of Southwest Ammunition.  The 4 rifles for the test are:

Mega Arms MKM MATEN 16” .308.  It is equipped with a Rainier Arms Select .308 mid-gas stainless barrel with a 1:11 polygonal twist.  Suppressed with an AAC 18T 7.62SD

LaRue Tactical 7.62 18” OBR.  It is equipped with a Lothar Walther 7.62 rifle-gas LW-50 stainless barrel with a 1:11.25 polygonal twist.  Suppressed with an AAC 18T 7.62SD

Mega Arms MKM MATEN 20” .308.  It is equipped with a Lilja .308 rifle-gas stainless barrel with a 3-groove 1:11 twist.

FNH SPR 24” .308.  It is equipped with a 24” 1:12 twist barrel.  Suppressed with a YHM Stainless 7.62 Phantom QD




The MagnetoSpeed LLC chronograph is an incredible piece of equipment that will allow you to quickly and efficiently test multiple things at one time.  We were able to test all 4 rifles on the same day for both accuracy and chronograph numbers.  My favorite feature of the MagnetoSpeed chronograph is that you can shoot at targets and there are no sun screens to worry about!

We found that the average loss in velocity between all 4 rifles was very consistent and the standard deviation between all the different loads was minimal.  This showed that the Southwest Ammunition is indeed very accurate.  We tested all .308 ammunition in the following loads.  168 grain SMK, 150 grain Nosler Ballistic Tip (Deer Bombs),  SW118LR, 185 grain Berger Juggernaut, 180 grain Sierra GameKing, 178 grain Hornady A-Max, 175 grain Subsonic SMK*





The 180grn GameKing impressed me due to its low standard deviation across multiple guns and its accuracy.  While the standard deviation average for the 5 shot groups are not overly impressive, during the 16” initial groups there was a deviation of 3fps until the 5th shot.  Also, the GameKing grouped second only to the 185grn Bergers and just as well as the 178grn A-Max.  The 185grn Bergers were very accurate in all guns!  The 185grn Bergers are a fantastic load for someone wanting to shoot extremely long ranges with consistency.  The 178grn A-Max would be my choice for a gas gun as it is a do it all bullet for the OBR and the 16” MKM.  With a SD of only 9 in the OBR and 10 in the 16” MKM the 178grn A-Max is my choice from Southwest Ammunition.  Also, the A-Max kills with consistency and is very accurate, which means you can use your hunting ammo in a match if you desired.  All loads that were tested showed a lot of promise, and would definitely serve you well depending on the application.  The 150grn Deer Bombs will work very well on anything you wish to hunt and with their speed, should prove dependable on any medium game.

The groups 2 groups below are from the OBR at 100 yards with the 178 A-Max and 180 GameKing.  (I did not photograph a lot of the groups.  I found fatigue to be an issue while testing such a large number of different loads and while the guns and ammunition was performing great, I was starting to show signs of opening up the groups and we also started to run out of time)


Below is the 185 Bergers in the 16″ MKM Maten.  5 rounds 100 yards


The last load we tested was the 175grn SMK Subsonic ammunition.  When we started this test everyone on the firing line would stop shooting and come watch.  The giggles alone from the group of grown men watching this makes them worth the money.  I had a slight issue with getting the Subsonics to chronograph and I believe it was my fault due to not making the strap on the chronograph stay tight.  However, with that said we only had 1 or 2 rounds total that sounded like they went supersonic, and they were just barely at that point and both with the 16” MKM.  Also, surprisingly to me, the longer the barrel the more consistent the subs were.  It sounded as though the OBR and the bolt gun were about the same as far as suppression level, but the 16” gun seemed less consistent and we had a hard time with getting the subs to show a reading with the 16”.   I did find that the 4 mil hold at 100yds with the subsonics allowed me to put up around a 1” group while shooting fast.  The subsonic ammunition was very consistent in the 18” OBR and the 24” bolt gun, yielding a SD of only 5fps in the OBR.  Subsonic .308 is a lot of fun, and every trigger pull made the shooter smile.  I hope to try some of these up close on a pig soon, and will report back with results.

Click on the Graph and Chart for a full size image.



I learned a lot about the different platforms of gas guns and bolt guns in this test.  If you plan on shooting a heavy AR I would recommend looking at the chart/table provided and look what the ammunition will do.  Also, I found that the difference between the 20” MKM and the 24” bolt gun was not as significant as I expected.  I believe that a 20″ Gas Gun can hang with most 24″ bolt guns to 800 or so yards, but I believe a bolt action is necessary to have the consistency needed to shoot beyond 800 yards.  Some gas guns are more than capable of shooting at those distances, but they require a little more stability than the bolt action guns.

The following is from Chad L (GlockandRoll)  He helped me with the initial test above.

“First, let me please extend my thanks to both Southwest Ammunition and Magneto speed for making this possible. This test is the result of a long time back and forth discussion between Jason and me about how exterior ballistics were affected by the use of suppressors and different barrel lengths with different twist rates in what we considered the perfect multi-use rifle; which would be something equally good in a precision multi-gun match, hunting, or even defensive use.

I met Jason in the ‘Let Texas Shoot’ benefit match a few years ago where we had laughs as the day went on especially one of the final stages that was on the back porch of the ranch house with a 900 yard shot on a steel kangaroo with extreme high heat and wind. It drove a lot of the .308 auto-guys nuts and it led to a never ending discussion between us and a lasting friendship, heck he even let me go on a ride-out with him on patrol on a Friday night.

As far equipment goes we are both best described as perfectionists when it comes to our rigs – not to be confused with snobs who think it has to cost the most – we just want it to be reliable, accurate, and durable even under hard use.  We like gas-impinged guns with medium powered optics in the 1-8x, 2-10x range with suppressors that aren’t too heavy, and we also like bolt actions to really get out there and reach something and we see them for two different uses, as do most. We always agreed on this, but what we seemed to always manage to bicker about was how badly barrel length affected velocity. And even if I had data from one rifle, with a given load, it may not be applicable for a different rifle in different condition.

We looked to see if anyone had done anything like this, and didn’t see it. What Jason wanted, which was brilliant, was a controlled test showing 4 different barrel lengths from 3 different autos between 16-20”; and then a 24” bolt guns on the same day from a single ammo supplier. All through silencers. Because, well let’s face it, shooting without a silencer is just rude.

Needless to say we had a great time and hope this data is useful for others. I learned a few things also. For one, I found a new 308 hunting round in the SWA 185grn Berger Juggernaut. The consistency in my 24” FN was astonishing. Bullet through the same hole accurate, and, the 20” bbl gas gun was nearly as quick. But, look at what happens out of the 16 and 18” guns? Also take a look at the 168 and 175 M118LR, it’s very linear not just in velocity, but it was consistent.

The 178 A-Max seemed to really love the increased barrel length of the bolt-action rifle, and the heavier bullets were pretty consistent from shorter length BBLs. At least more consistent than I would have expected. Personally, I found the 20” Lilja BBL to be the best compromise for me. I feel confident that I could engage targets to 1K, and it wasn’t as heavy as the built gun.

We had a lot of fun shooting this, and their subsonic ammo was SPECTACULAR, however the chrono did not pick up the velocities, but we hope the video shows just how quiet it was.  And, as you may notice, we did not test the 155 scenar because we felt this was something that would pretty much be used exclusively in a 24” + bbl 308.. but we hope to do some testing of just this round from SWA in my FN as it’s such a proven consistent performer.”


Next, I went to the Tac Pro Shooting Center in Mingas Texas for their 2 day Precision Rifle course.  For this course I called Curtis with Templar Tactical and used one of their Seneschal 24″ .308 rifles with a 1:11.25 twist Bartlien barrel.  The rifle was equipped with a Harris bipod, Templar Tactical 34mm rings, a Templar Tactical 2 chamber brake for suppressor attachment, and a Bushnell Elite Tactical XRS 4.5-30x50mm rifle scope.


Before I move on to the class, I want to talk about the rifle.  This rifle belongs to the owner of Templar Tactical and has seen some good use.  The McMillian A5 stock has some wear and shows signs of use, no safe queen here!  The fit of this rifle is fantastic.  The edges are smooth, mags drop free and insert without issue and the feeding is flawless.  Someone has definitely broke this rifle in right as the bolt is smooth as silk, and the Jewel trigger very consistent.  It is not only a pleasure to shoot, but as you will see below, it is a hammer.



The Tac Pro Shooting Center 2 day precision rifle course was taught by Bill Davidson and Mike Moore.  The course covers fundamentals of precision shooting, equipment selection, mathematics of trajectory, range estimation and more.  During the class we gathered data on our rifles from 100 yards, 200 yards and 500 yards.  Evaluated our equipment to see if it was set up properly and checked the scopes for proper tracking.  We were taught how to estimate target ranges using mathematics and the reticle in the scope.  (This is an invaluable skill that takes a lot of practice)  We went to the unknown distance range and put range estimation to the test and then shot at the distances we ranged to.  Finally, we took all the skills we learned and moved over to the 1000 yard line where we engaged a series of steel targets and some clays.  Something of note:  Clay pigeons at 1000 yards in the wind is a measure of frustration and hits on steel become easy after a few misses on a clay target. When shooting precision rifles, I learned that consistency is the most important thing.  Being consistent with your ammunition, consistent in your fundamentals, and being consistent with your range estimation will help you get maximum hits on target.

Below is the 100yd box test.  Using 168grn SMKs and 3 round groups, all rounds were fired at the bottom left target.  The Bushnell XRS 4.5-30×50 tracked perfectly.


During this course, I had no issue with anything equipment related using the Templar Tactical rifle and all my hits were easy using the Southwest ammunition.  For the entirety of the course I used Southwest Ammunition 168 grain SMK and 178 grain A-Max.  Below is a chart of ballistic data I collected using the ammunition I noted.  Also, below is a chart of chronograph data gathered for the course.  Notice how the Templar Tactical rifle using the same barrel length is about 100fps slower than the FN, but that the Templar Tactical rifle has a smaller standard deviation for both loads.  Both rifles were accurate, but the Templar Tactical rifle really did like both the 168grn SMK and the 178 A-Max as you can tell by my 100yd groups.


The below picture has a flier that was shooter induced.  I slapped the trigger and pushed it low and left.


The below group is 5 rounds of 168grn SMK at 100yds.


The below picture is a 5 round group of 178grn A-Max at 100yds.


The below group is 4 rounds of 168grn SMK at 500 yards in the wind.  3/4 value at gusting to 14mph.  The 5th round of this group was a flier I pushed due to fundamentals.  I could see my impacts at 500 and knew when I let the shot go it was off.


Over the last several months I had the pleasure to use Southwest Ammunition in 5 different rifles, all with very different uses.  I have learned that consistency is the key, and that is what Southwest Ammunition excels at.  Not only does Southwest make a load that will fit the mission you need, but they will do so affordably.  As someone trying to get into the Precision rifle matches, I plan to buy a 6.5CM chambered rifle.  Unfortunately Southwest Ammunition does not currently make anything in this caliber, but I am hoping that will change in the near future and would ask them to consider this as a future addition to their product line up.

Having attended a Precision Rifle course during my evaluation period, I now believe I have a good understanding of what the .308 is capable of.  With proper ammunition, a .308 AR is capable of hits to 800 and beyond, and a .308 bolt gun is good out to around 1000 yards.  If you are in the wind, the .308 is not your friend.  I also believe that shorter .308 AR rifles are a lot of fun when suppressed and can make great hunting guns if you don’t mind the added weight.  I hope the ballistic information provided with this article is beneficial to anyone who uses it.  Make sure you look at Southwest Ammunition the next time you are needing something for precision shooting.  Thank you to Southwest Ammunition, MagnetoSpeed LLC, Templar Tactical and Tac Pro Shooting Center.

img_3425 img_3428   img_3417 img_3410     img_3404

By: JH

The following two tabs change content below.
Jason's love of shooting sports started at an early age hunting with his father in the pastures of West Texas. Jason is now Full Time Law Enforcement and shoots competitively when he can.

Latest posts by Jason Hallmark (see all)