The Foxtrot Mike FM9 bolt is a commonly available AR9 bolt which is often quite inexpensive. Unfortunately, the FM9 bolt does not function in a standard SMP40 build. It drags against ejector, collides with the feed ramp, and causes the charging handle cutout to not line up properly.
This package contains parts to replace the original versions in the SMP40 release package, in order to allow the SMP40 build to run with an FM9 bolt.
No additional hardware is required - the same pins, screws, etc. can be used to install these as are used in the original build.
There are three parts that can be printed:
- FM9 Feed Ramp
- FM9 Magwell
- FM9 Charging Handle Cover
There are two versions of the charging handle cover:
"Printed Charging Handle Cover", for printed charging handles, originally designed by Mr. Ruthless
"Machined Charging Handle Cover", for the machined charging handle, modified from the Mr. Ruthless design
The ejector must also be replaced. A DXF is included for the new ejector design. This ejector will only work with the FM9 magwell, because the pinhole to secure the ejector was moved. You can also purchase an FM9 ejector from 3dprintfreedom.com.
If fabricating yourself, these ejectors should be made from steel, between 1.5mm and 2mm thick (1/16" should work).
An STL for the ejector is included, which can be printed and used for testing purposes, but don't expect this to survive real use.
LBRY Tags: guncad; smp40; 3d2a; mp40