The values shown for hole depths are subject to the draft. The PPU 55 stuff gives me around 3260 fps from this barrel. Optimum greatest depth of cored holes as related to diameter is shown in the table. Product ejection cannot be neglected, and during the ejection process, the product should be protected from deformation, ejector marks, cracking and other damages. ![]() My load workup I chose to start with is using starline brass, cci 400, Hornady 140gr eld match bullets, and powered by h4350 starting with 39 grains of powder. The rifle is a Windham 20" with Govt profile barrel 1/7. Pretty much right out the gate with my starting loads I started having ejector marks on the brass. Gas leaking around the primer.-Loose primer pocket in 5 firings or less.-Web has expanded more that. I then fired a bunch of new factory rounds (PPU 55 gr FMJBT / not their M193 clone), and I found ejector marks on 2 out of 10. The ejector mark is raised, flowing into the hole.-Primer cratering, flowing back into the firing pin hole,but can be a Remington bolt with chamfered firing pin tunnel. Primers look fine, no flattening, nothing loose. I've stepped down, trying 22.1 to 23.3, velocities is now in a safe range from 2600 - 2680 fps.īut again I saw ejector marks on most rounds. Can you eliminate ejector pins marks I am working on an air pressure expulsion mechanism for plastic injection molds, to avoid the use of ejector pins and. Product design: Inappropriate product design: 1). Now this combination is far from unusual, however even with Sierras conservative data (max 24.5, accuracy load 24.1) I was getting ejector marks on all fired rounds.Īnd probably too hot velocities starting at 2700 fps with 23.5 gr up to 2800 fps with 24.5. Ejector pin marks usually refer to the glossy or white imprints on the surface of a injection molded product, as well as the different levels of glossiness dark or shadow, without convex or concave visible directly opposite to the ejector pin location. ![]() I am using PPU 556 brass to find a decent LR load with 77 SMKs and N140. As you might expect, ejector marks are those that are left on a fired cartridge case that’s used in a semi-automatic rifle or pistol.
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