Bite The Bullet
Save Your Cocking Lever (2001-01-10)
If you are a big MP5 fan like me and have been enthusiastic enough to install metal parts on it (including a metal cocking tube), chances are that you have experienced the dismay snapping off your cocking lever within the first 5 minutes. While Marui AEGs are built to last, we must remember that they are, after all, expensive toys and should be treated with care. Now while I knew this all too well, I was still tempted to cock my MP5 immediately after I had installed a front cocking tube. Pulling it all the way back and then letting go, I was after the beautiful "ka-chink" which I was hoping for. Alas the cocking lever flew forward, reached it's limit on the cocking tube, snapped off without a sound and kept on flying forward for another 4 feet! Ouch.
The fact is that many metal parts on airsoft guns are actually made out of composite metal and are much less stronger than say, pure steel. As such, excessive impact will break these parts in half, much like plastic. But if you really want to snap down on the cocking lever to get that authentic feel, despair not for we will teach you a trick!
The key here is to avoid impact between the lever and the front cocking tube body. It is this impact that snaps the throat of the lever. Start by finding a piece of plastic tubing that you can cut down to any specific length with either a small saw of a cutter blade. Next, disassemble the front portion of your MP5 (works for either MP5 A4/A5 or SD series). We'll use the MP5 A5 here as an example. First take a small hex wrench and loosen the bolt on the underside of the front sight. This releases the 3-lug muzzle on the A5 which you can pull out. Next, using a screwdriver and your thumbs, unscrew the retaining pin (combo sling mount) and remove it from the front sight. At this point, the front sight should pull away easily from the front cocking tube assembly.
At this point, you should be able to look into the cocking tube (the hole above the barrel which is the one that houses the cocking lever. If you look down into the hole, you should see a small screw in the center of a black hub. This is the cocking lever bolt you are looking at. The object here is to wedge your piece of plastic into this hole so that it pushes against the cocking lever bolt. Take your piece of plastic and push it in. If you push it in deep, you should be able to move the cocking bolt/lever backwards. Look at the 2 diagrams above to see where the piece of plastic inserts into. One critical point of understanding here is that once the front sight is mounted back onto the front cocking tube, it (the front sight) rests flush with the front of the cocking tube and therefore pushes in your little piece of plastic against the cocking bolt/lever. You should therefore push the piece of plastic in until you see the lever move back in the cocking tube but a couple millimeters (see diagram below which shows a small resulting gap). Stop and using a knife of pen, make a mark on the plastic stick at the point where the stick is exiting the cocking tube on the front. This point is where you want to cut the stick. Once you cut the plastic stick, place it back into the cocking tube. At rest and firmly pushed up against the cocking bolt, it should stick out a bit from the front cocking tube as shown in the top diagram.
You are now ready to reassemble the front sight and the rest of the muzzle. Once you assemble the front sight, it will push on the plastic stick, thereby also pushing back on the cocking lever. Reassemble and tighten everything and you're done! Make sure there is a small resulting gap from your work. If there is no gap and the cocking lever is making full contact with the front of the cocking slot, then you cut the piece of stick too short and will have to try again. Be careful not to choose a stick that is too soft or too thin since it may end up bending under pressure and lose it's effect. If you have done this right, you can cock the lever as many times as you like, and even snap it down from the fully cocked and locked position without fear of having to ever break another lever!