37mm Aerial Signal Practice Rounds DIY Mil 433 Styled S/M/L Sized Cones | eBay
(You provide Chalk, visco fz, pyrodex and 209 pmr). These so far have worked in every 37mm launcher we have been able to test with (spikes, 3d2a FP models, exotic TAC series, Deftec/penn arms, ML37,...
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