Competition loading of the M4, lighten the shell stop pressure.

[NoTycoon]

Thanks to new member Kidek for this question.

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If you have time, could you please share experience, how to mod shell catch? As its really impossible to do quad reloads with the stiffness on the original part. 

I also experienced difficulty loading due to the stiffness of the shell catch. So, here is what I have done to lighten the pressure on the shell catch.

Using a Dremel tool (love that thing), I opened the notches on the sides of the shell stop tab. This increases the bendable area.

In the picture below, the lower part is the modified shell stop.  The upper is unmodified.  For you purists, the unmodified cutouts are 2.39 mm wide and the metal between them is 9.36 mm thick.

On the modified shell stop, the cutouts are 6.53 mm and 7.56 mm (I will be cutting the new one to 7.5 each) and the metal between them is 8.32 mm (I may not cut so deep on my next one).  Note that the rear cut does not remove any of the angled metal; however, the forward cut does.

NOTE: the new shell stop plate is drilled for a GG&G bolt release button.  If you have one, or are going to install one, consider scooping out the underside of the forward edge. This gives you enough purchase to use the button as a lifter to more easily unload rounds from the tube (i.e. lift the shell stop catch away from the shell).