MM Firefly 10KG Main Spring

Struggling to prime the stock 12KG spring on your Firefly Blaster? The MM Firefly 10KG Main Spring trades a small amount of power for a noticeably lighter pull, dropping output by roughly 20 FPS while making the priming stroke meaningfully easier on your hand and wrist.

Rated at 10KG, it chronographs at 170-180 FPS with Worker Gen 3 Darts in a Firefly — still well within springer-sniper territory, just without the full effort of the stock spring. It's a straightforward swap for anyone who finds the standard Firefly hard to cycle repeatedly, whether that's younger players, longer skirmish days, or just wanting a lighter feel without stepping all the way down to a low-power spring. Fitting it follows the same process as any Firefly main spring replacement, with no other parts to change.