Z-RAM Z.50 vs Z.50v2 for Umarex HDR50/TR50: Identifying the Versions
Z-RAM's first Z.50 presentation identifies a 4.5 g projectile; the Z.50v2 introduction identifies a 6 g design with side grooves. Here is how those versions relate to today's two .50 listings for Umarex HDR50/TR50.
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