Product Overview
This is the StopBlock, made for your Super Safety equipped MP5 clone when using an LS trigger housing.
The StopBlock prevents Safety overtravel and also works as a centering block. It protects the cam from damage caused by over-rotation of the Safety if it is struck by the SlipTrip when using a LS trigger housing.
Compatible with LS trigger housings only.
Printed in Polymaker PA12-CF and annealed.
INSTRUCTIONS: Before installing the Lever Stop Block into the Lee Sporting housing, first install the SS cam and lever directly into the Lever Stop Block and manually rotate the lever by hand while squeezing the sides to ensure it can pivot freely in both directions, and clear out any debris.
Reviews
5 Reviews Hide Reviews Show Reviews
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5 Stop Block
Posted by Marcus Leichner on Dec 23rd 2025
Needed to cut the front off and sand a lot for it to work with the AS Designs Arc-Fire, but it was completely necessary to use this part to get the Arc-Fire to work in my Lee Sporting lower
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5 Great Addition
Posted by Kirk on Jul 29th 2025
It took quite a bit of sanding on basically every surface on this to get it to fit and I ended up with a weird hammer interference issue originally causing the bolt to bind up. Once all that was resolved however, it's a nice snug fit and does it's job.
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5 MP5 Trigger Housing Stop Block
Posted by Matthew Wheatley on Jul 21st 2025
Works great. Very innovative and a needed part to keep a Lee Sporting lower in good shape when running a super-safety.
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5 Stop block
Posted by Robert Mahood on Jul 2nd 2025
Well made fits with no modification. easy installation
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5 MP5 stop block
Posted by Jack on May 28th 2025
I’ve had the stop block for a few weeks but finally got the chance to install it and test it out. I installed it in a Lee lower used in a K sized MKE gun. The gun has been running fine with a GMR Super Safety and slip trip, but after reading about some SS levers breaking in Lee lowers because of over travel, I decided to try the stop block. It’s a very tight fit in the lower, and inserting the lever and barrel are both difficult because they are tight also. (Tight is good.) I took the gun to the range and it functioned fine in semi and SS mode for 100 rounds. Time will tell if this prevents any issues, but for now it works as advertised.
