MM BK1S Mag Base

The MM BK1S Mag Base is a friction-fit extension that bumps your BK1/BK1S/BK2S magazine's capacity up to a comfortable 15 rounds while still running the stock spring — no spring upgrade needed. It simply clips onto the base of your existing magazine, so there's nothing to modify on the mag itself.

The base is finished with TPU feet on the bottom, which absorb impact if you drop the magazine on a hard floor instead of transferring the shock straight into the mag body. It's the simpler of our two mag-extension options — if you also want a dart-count indicator built in, look at the MM BK1S Mag Sleeve instead. Available in nine colours: Black, White, Orange, Yellow, Pink, Silver, Dark Gray, Light Blue, and Purple.