Leber V2 Super Safety Troubleshooting & Common Issues

As a baseline, start with high quality 124 grain ammo (we use S&B or Fiochi)

If issues persist, replace the following parts in order:

Extractor spring, Extractor, Ejector Lever.

We recommend using authentic HK parts, specifically the gen 3 ejector lever.

Two options:

1. Heavy weight hammer spring (has it's own drawbacks)

2. Cut approximately 1/4th of your firing pin spring off completely

This is almost always caused by the MP5 having too much oil. Yes, this is a thing - I didn't believe it myself until it happened to me.

If you aren't using genuine HK magazines, please consider the change. They will eliminate most of your issues, as well as provide a consistent baseline to diagnose any future issues.

The FCG Pack is designed to be slightly adjustable, and can move back & forth a few thousands of an inch.

The rear reinformcement plate is designed to be slightly adjustable, and can move back & forth slightly to accomodate varying platforms. For K platforms, there isn't much adjustablity.

This issue is very prevalent in the Nylon slip trip — the best course of action is to trim a bit of material from the bottom side of the upper ledge, as some MP5s are clamped together tighter than others.

Reference photo (basic slip trip pictured):

Using 400 grit sand paper, sand the rounded side of trigger - be sure to keep the contour of the trigger & avoid flat spots. Be careful not to take off too much material. We recommend continuously testing the trigger pull between sanding.

You could also sand the leading edge of the cam, but the trigger is the cheaper & easier item to replace in the event too much material is removed.

Option A (not our preference):

Option B (sand round side of trigger):

Most common issue is the FCG plate being slightly bent; this isn't a big deal just ensure the left side of the plate (where ejector lever axle rides) is straight

Reference photo (coming soon):

Sticky feeling is caused by the ejector channel being tight, sand w/ 180-300 grit until free. Overall this won't affect function.

This is indicitive of a larger underlying issue(s), The most common being too much bolt carrier energy. This can be solved by using a different locking piece, which will also prevent roller dents.