How to Prep Mil-Surp 5.56 Lake City Brass — Save Money

The U.S. Army Marksmanship Unit regularly publishes a reloading “how-to” article on the USAMU Facebook page. One excellent “Handloading Hump Day” post covered preparation of once-fired 5.56x45mm brass. This article, the first in a 3-part series, has many useful tips. If you shoot a rifle chambered in .223 Rem or 5.56x45mm, this article is worth reading.

This week, Handloading Hump-Day will answer a special request from several competitive shooters who asked about procedures for morphing once-fired GI 5.56mm brass into accurate match brass for NRA High Power Rifle use. The USAMU has used virgin Lake City (LC) 5.56 brass to win National Championships and set National Records for many years. In this 3-part series, we’ll share techniques proven to wring match-winning accuracy from combat-grade brass.

GI brass has an excellent attribute, worth noting — it is virtually indestructible. Due to its NATO-spec hardness, the primer pockets last much longer than most commercial brass when using loads at appropriate pressures.

Preparing Once-Fired GI 5.56 Brass for Reloading (Part 1 of 3)

Assuming our readers will be getting brass once-fired as received from surplus dealers, the following steps can help process the low-cost raw material into reliably accurate components.

1. Clean the Brass
First, clean the brass of any dirt/mud/debris, if applicable. Depending on the brass’s condition, washing it in a soap solution followed by a thorough rinsing may help. [This step also extends the life of the tumbling media.] Approaches range from low-tech, using gallon jugs 1/2 full of water/dish soap plus brass and shaking vigorously, to more high-tech, expensive and time-consuming methods.

2. Wet-Tumbling Options (Be Sure to Dry the Brass)
When applying the final cleaning/polish, some use tumblers with liquid cleaning media and stainless steel pins for a brilliant shine inside and out, while others take the traditional vibratory tumbler/ground media approach. Degree of case shine is purely personal preference, but the key issue is simple cleanliness to avoid scratching ones’ dies.

If a liquid cleaner is used, be SURE to dry the cases thoroughly to preclude corrosion inside. One method is to dump the wet brass into an old pillow case, then tilt it left/right so the cases re-orient themselves while shifting from corner to corner. Several repetitions, pausing at each corner until water stops draining, will remove most water. They can then be left to air-dry on a towel, or can be dried in a warm (150° F-200° F max) oven for a few minutes to speed evaporation.

Shown below are Lake City cases after cleaning with Stainless Media (STM). Note: STM Case cleaning was done by a third party, not the USAMU, which does not endorse any particular cleaning method.

3. Inspect Every Case
Once dry, inspect each case for significant deformation (i.e., someone stepped on it), damaged mouths/necks and case head/rim damage. Some rifles’ ejectors actually dig small chunks of brass out of the case head — obviously, not ideal for precision shooting. Similarly, some extractors can bend the case rims so badly that distortion is visible when spinning them in one’s fingers. These can be used for plinking, but our match brass should have straight, undamaged rims.

Dented case mouths are common, and these can easily be rounded using a conical, tapered tool, [such as a .223 expander mandrel. A dummy 7.62 or .30-06 cartridge with a FMJ spitzer can also work.] If most of your brass is of one headstamp, this is a good time to cull out any odd cases.

4. Check the Primers Before Decapping
Your clean, dry and inspected brass is now ready for full-length sizing, decapping and re-priming. Historically, primer crimps on GI brass have caused some head-scratching (and vile language) among handloaders. Our next installment will detail efficient, easy and practical methods to remove primer crimp, plus other useful handloading tips. Until next week, Good Shooting!

NOTE: The USAMU Handloading (HL) Shop does not RE-load fired 5.56 brass. We use virgin LC brass with our chosen primer already staked in place. However, our staff has extensive personal experience reloading GI brass for competition, which will supplement the Shop’s customary steps. In handloading, as in life, there are many ways to accomplish any given task. Our suggestions are note presented as the “only way,” by any means. Time for loading/practicing is always at a premium. Readers who have more efficient, alternative methods that maintain top accuracy are invited to share them here.

Accuracy Potential of Mil-Surp 5.56×45 Brass

So, how accurate can previously-fired GI surplus brass be in a good National Match AR-15? Well, here’s a data point from many years ago that might be of interest. A High Power shooter who wrote for the late Precision Shooting magazine took a Bill Wylde-built AR match rifle to a registered Benchrest match. His first 5-round group ever fired in a BR match was officially measured at 0.231″ at 200 hundred yards. This was fired in front of witnesses, while using a moving target backer that confirmed all five rounds were fired.

He recounted that his ammo was loaded progressively with factory 52gr match bullets and a spherical powder using mixed years of LC brass with no special preparation whatsoever. Obviously, this was “exceptional”. However, he had no difficulty obtaining consistent 0.5-0.6 MOA accuracy at 200 yards using LC brass and a generic “practice” load that was not tuned to his rifle.

Saving Money by Using GI Brass

So, with good commercial brass readily available, why would one go to all the extra steps necessary to process fired GI brass? [Editor: It’s about saving money.]

Economically, it makes great sense. When the author was actively practicing and competing with the service rifle, he had ~3,000 rounds of 5.56mm brass, which allowed him to load during winter and spend most time in the summer practicing. If one were wealthy and wanted to shoot nothing but the finest imported brass, the current cost of 3,000 is ~$1920 (plus shipping.)

Dropping down to good, but less-expensive new, U.S. commercial brass brings the price to a much more realistic ~$720. However, at current rates, the same amount of surplus GI once-fired brass costs between $120 — $150, leaving lots of room in the budget for other expenses. [Editor: that’s less than 10% of the cost of the best imported brass.]