MK18 compact

If you, like me, don't use shells when playing with NERF blasters, then this remix of [Meaker's MK18 Assault Pistol](https://www.thingiverse.com/thing:3219077) might be for you.

With a 100mm 5kg (Alpha Trooper upgrade) spring and 30mm compression lenght, this blaster can be loaded and shot by a 6 year old, and outshoots my stock nerfs.

This is an upgrade - that means that you need to print an almost complete [original thing](https://www.thingiverse.com/thing:3219077) (R3 or R4, both are compatible) without these parts:
- plunger rod: t pull / prlt (filename depends on the version)
- plunger head: ph 212/213 oring
- any shells or front attachments
- if your spring is ID