June 1st, 2011

New Lapua 220 Russian Brass — Thicker Necks?

220 Russian brass lapuaJackie Schmidt, posting on Benchrest Central, observed that there may have been some production changes with Lapua 220 Russian brass. This brass is commonly used as the parent case for fire-forming 6 PPC cases. The newer 220 Russian brass has slightly thicker neckwalls, and, according to Jackie, the new brass is more consistent in overall neckwall thickness.

Jackie writes: “I have not made any new PPC cases in a while. But I finally used up all of my older 220 Russian brass, and just bought 500 new cases, in the blue plastic boxes. The necks are thicker. By at least .0008 (eight ten-thousandths). That is right at .0015 on diameter. I am getting neck-wall thickness of .0142″ on the old cases, .0150″ on the new cases. I [fire-formed] two cases, and seated a Flat Base Ultra bullet in each. The old case, with a seated bullet and non-neck-turned case, measures .2708″ average. By contrast, the new case, with a seated bullet in an unturned neck, measures .2722″ average. That is, on average, about .0015 difference in the diameter of a seated round.”

“Anybody else notice this? I guess the main reason I did the measuring is that I am thinking of having a ‘no-neck turn’ reamer ground. With this new brass, .0274″ would be the minimum. The new brass is a tad better in overall [neck]-wall thickness variation.” — Jackie

What does Lapua say? We’ve sent inquiries to Lapua’s USA tech representatives. We hope to have a response soon.

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