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.338 Lapua Magnum Brass Cartridge Cases

The .338 Lapua Magnum Brass Cartridge is manufactured on Peterson Cartridge’s new, state-of-the-art case line which uses cutting-edge technology to produce some of the most precise and consistent casings on the market. Peterson Cartridge Co is committed to producing Match-Grade Brass that enables our customers to get more reloads per casing than industry average.


When Peterson Cartridge decided to come out with its own .338 Lapua Mag casing we perceived that there was not a source of really good, match-grade, sniper quality .338 Lapua that was made in the US. We decided that if we were going to produce .338s, we wanted ours to be as good as or better than the best foreign-made .338 L M.

So we spent more than a year studying the casings of the best foreign manufacturers. We ran scores of tests on annealing temperatures to get the grain structure just right. SAAMI, the standards organization for our industry, specs outside dimensions of casings but there are no specs on internal dimensions. So we cut casings in half and studied the internal geometry of the best, to uncover their secrets, and where possible, improve on them. In our lab we have an electronic machine that measures the force required to insert a projectile into the case mouth – what we call neck tension. This enabled us to ensure that our casings were optimal for bullet release. The end result is what we believe to be the most accurate shooting .338 Lapua Mag casings on the market.

We’re not the only ones to think these are exceptionally good casings. We sell a ton of our .338 LMs to international sniper units. And we know of at least one hostage situation in the US that was resolved with a round using Peterson .338 LM brass. So if you would like to use the case used by military sniper units and police SWAT teams, you need look no further than Peterson Cartridge.

What we hear from our customers a lot is, “You make it easy to buy Peterson. It is as good as the best! It’s less expensive! And it’s made in the US!”

Warning: Only use Peterson Cartridge Co. casings in firearms in good condition, designed, marked, and chambered for this cartridge. Do not use Peterson Cartridge Co casings for “fire forming” or any other purpose other than what they were designed and tested for. Peterson retains no responsibility for the enclosed casings if they are used outside of the manufacturer’s recommendations.

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Extremely consistent, American-made brass rifle casings and ammunition, designed for long-distance shooters.