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Type 1 SMG Starts Shipping Tomorrow

If anyone is having an issue with the bolt hold open (only with a mag in) then it’s holding the bolt too far aft, hanging on the follower and not allowing it to engage the hold open. Given dimensional differences on these old Czech mags this can be an issue. I’m sure SMG would have no problem fixing this minor squawk, but if you’re like me and don’t want to surrender your new toy, it’s an easy fix.

Without a mag in, retract the bolt to the rear, engage the bolt hold open, under the compression of the main spring, the bolt hold open will remain latched in detent. Now insert a mag, and try the same, if the hold open remains freely movable then it’s hanging on the mag and not on its proper detent. The follower will require minor dressing to facilitate proper hold open function in practical use.

If you have determined this to be the case, disassemble the mag, wrap the follower in leather and mount it low in a vise. The followers are hardened so you’ll need a good sharp file to break through the case hardening. You only need to file on roughly 1/4” of the back of the follower as this is the only point that contacts the bolt face. A single cut file is all that is necessary, as you don’t need to remove too much at once. Due to dimensional mag differences, it’s good to fit each mag individually against the rifle. Only remove a few thousandths at a time, making sure to squarely and evenly dress the part. Reassemble the mag, insert it into the rifle and give it a functional test again. I did this in about five fit checks per magazine to get them functioning flawlessly. Continue until the point when you can (with the mag inserted) engage the hold open, and freely depress the follower. Once you get to this point you are close, but still be mindful to hang onto the charging handle as it will still disrupt the bolt from the hold open as you remove the mag. It will still not completely function and this is due to the magazine geometry now, given that it is a rock in style mag. As the mag rotates out of the rifle the rear tip of the follower will now contact the bolt as it makes this arc. File a small bevel across the top edge of the follower to allow clearance for its removal geometry. Once you are there, bolt hold open engaged and mags freely removable, check them a few times in and out of the rifle to make sure they don’t trip the bolt. Thoroughly clean the mags out, oil them before final assembly, load them up and have fun!

This applies to the Type 1, I’m not sure if the same issues are necessarily at play with the Type 2. Possible issues I can think of are follower hardness, if you are unable to initially file the back of the follower, it may require grinding in the initial step until you cut through the case hardening. Mine required roughly .025 removed off the rear face to get the follower to initially clear the bolt, magazine dimensions will vary so only use that as a guide, and rather follow the procedure to get to that point.
 

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