Speed Seal Plunger for BK1S/BK2S

Theorized, Designed, and created in the BCFF Ecosystem - an upgraded plunger for the Zius BK1S and BK2S. SLS printed in Nylon by a local canadian fab-shop. 

This has been our starting point for improvement, pretty much the first step needed to push the performance on the Zius BK1S/BK2S blaster.

This is a speed seal plunger, the o-ring will feel looser and floppy untill air pressure/friction is pushing into it's sealing position. Which results in low drag during priming strokes, but positive seal when firing. 

What you'll receive - is an assembled ready to install plunger, remove the rack from your current plunger - install on the replacement reusing the factory screw, lube the oring with a light silicone lubricant and install. 

3 additional thicker blue TPU bumpers are included, some people wish to make the rack teeth align better, this allows you some options to accommodate wear and differing pad thicknesses from the factory - just cut the black bumper off and CA/Superglue the thicker pad on if you wish (try to line up the porting holes). Personally I don't see a need - both racks can move as the sector gear engages, I've found no operational difference between aligned and misaligned.

The new lightened variant is now being shipped, if you want the original plunger, I do have a few left in stock, please shoot me an email and ask for it.