.338 Lapua Magnum Revisited

By Mark V. Lonsdale, STTU

Unlike many who have migrated to the raft of newer calibers in the past 10 years, I have remained a firm proponent of .308 Win  and .300 WinMag for several reasons, not the least of which are accuracy, reliability, availability, and cost. But in recent years I had worked with .375 CheyTac and .416 Barrett for ELR competitions. While .375 CT may have a place as a military sniper rifle, .416 Barrett is essentially a single purpose ELR rifle for reaching out passed 3,000 yards.

I first ran into the .338 Lapua Magnums (8.6x70mm) in Kosovo in 1999/2000 where the Accuracy International AWM (L115A1) had found favor with NATO military snipers. As an upgraded L115A3, the .338 LM also saw extensive use in Afghanistan and Iraq while US Navy SEALs made deadly use of the McMillan TAC-338.

However, I did not immediately jump on this caliber for a number of reasons: 1) my 300 WinMag could hit hard at 1,000 meters, and reach 1,500 meters; 2) the .338 LM was a bigger and heavier rifle; 3) 338 ammo was definitely more expensive, and; 4) it was not as readily available as it is now. But I have always remained open to anything that improves performance, so my thinking has since changed.


.416 Barrett in back (40 pounds) compared to the .338 Lapua Magnum (16.5 pounds). Both are running Bartlein barrels and McMillan stocks with Accu-Tac bipods 

While I did well with the .416 Barrett at the FCSA 1.5 mile match and 2019 King of 2 Miles (Ko2M) – first place team – my professional interests are focused more on rifles and calibers that have military or law enforcement applications. A 40-pound rifle is simply not a practical field rifle, but my Hill Country .375 CheyTac, at a lean 24 pounds, complete with scope and bipod, was more to my liking. I was also able to get nine out of ten hits at 2,200+ yards with the .375 – more than enough effective range for a long range sniper rifle.


Hill Country .375 CheyTac (back) with a Stiller’s TAC408 action and McMillan A5 SuperMagnum stock, with Accu-Tac bipod weighing in at 24 pounds. In front, the .338 Lapua Magnum built on a Stiller’s TAC338 action, Bartlein barrel, in the standard McMillan A5 stock weighing in at 16.5 pounds. 

But when some ELR competitions introduced a .338 and under class, I was motivated to build a .338 Lapua Magnum. This rifle began as a Stiller’s TAC338 action since I’d already had excellent performance from my Stiller’s TAC300 in 300 WinMag and TAC408 on the .375 CT. From there I added a Bartlein Heavy Palma barrel, Piercision muzzle brake, and drop it into a McMillan A5 stock with Badger M5 bottom metal. Now I had a lean 16.5-pound long range rifle complete with scope and magazine – but the proof would be in the performance.

Team mate, Derek Rodgers, had suggested I try VihtaVuori N170 powder for the .338, but since I didn’t have any loading data for this powder, I started out with a conservative 92 grains behind the Sierra 300 grain SMK. Along with Peterson brass and Federal Large Rifle Magnum Match (215M) primers, this came in at 2,680 fps. While all the groups were sub-MOA, and many 0.5 MOA, as I increased MV, I found the best groups at 2,950 fps. But then load development with the N170 stopped when I ran out of powder.

Loading components included Peterson brass, VV N170 powder, Federal Magnum Match primers (215M), Sierra 300 SMK and Cutting Edge 275 grain bullets. 

Because of the impact of the COVID virus on the arms industry, and reloading components in particular, I was unable to get more N170, Retumbo, or N570, and had already used up all my H1000 on .300 WinMag development and training. But since I had a good supply of H50BMG for my .375 CT, I began working up a load with this slower burning powder. Right from the start I was getting 0.5” groups or better at 100 yards as I gradually increased the load and muzzle velocity.


The .338 has proven to be very accurate with consistent sub-MOA 5-shot groups. Warning: anyone getting into reloading needs to approach the heavy loads incrementally and with caution while constantly monitoring brass and primers for signs of over pressure. 

As I sit here writing this, the testing continues. I already have the next three loads loaded up and ready for a trip to the range this week. I’ve also added the Hornady 285 grain ELD-M bullet to my testing.

20200213_Acc Lab

.338 Lapua Magnum with ballistic support from Labradar and Kestrel 5700 Elite with Applied Ballistics

At some point in the future, I would like to get the opportunity to shoot the .338 EnABler and .375 EnABler from Applied Ballistics since they are more suited to magazine fed rifles. With the USSOCOM interest in the .338 Norma Magnum, this caliber is also on my “to do” list.

So after decades of professional shooting, the .338 LM is definitely one of my go-to calibers and rifles. I feel sure that it will go down in history as one of the most utilized military and competition rounds, along with the venerable .308 Win (7.62x51mm) and .300 WinMag (7.62x67mmB). For anyone looking to get into ELR shooting, defined as 1,500 yards plus, the .338 LM is an excellent entry level caliber. But to run with the big dogs, an ELR shooter will need the longer legs of .375 CT or larger.


About Mark V

Dedicated shooter, seeker, traveler, teacher, trainer, educator
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