If you, like me, don't use shells when playing with NERF blasters, then this remix of Meaker's MK18 Assault Pistol 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 (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 <16mm, don't print the original catch plate

Then print my files instead:

• plunger rod: thin for springs with ID>13mm, and regular ID>16mm; cl is the compression length (26mm: spring is compressed to 26mm, 30mm is easier) According to empirical research, the regular rod is to be preferred, if possible: the above mentioned 6yo can accidentally snap the thin plunger rod.
• plunger head: atm only for 28mm ID tube, with 21x3.5mm o-ring, thin/regular like the rod. Yes, I got inspired by Cpt. Slug!
• thin catch plate: only needed for thin rod; the little tab goes on the opposite side of the catch and slips into the rear part. The original catch plate is used for the regular rod.
• barrel: one is for full length (narrow and a little wider - i prefer the latter), the other one for worker darts If you orient the parts properly, only the "barrel" part needs support. Business end goes up!

You will need 1 or 2 o-rings and some grease. The o-ring on the barrel is not needed if yon manage an air-tight seal between the part and tube in any other way (glue/tape/hammer, ...).

If you want/need, you can glue an anti shock pad between barrel and plunger (glue it to the barrel part of course) - a washer-shaped piece of rubber, EPDM, thin Evazote or other shock absorbing materials.

I'm open to suggestions/improvements/requests!