Mossberg 715T Spontaneous Bolt Lock

Another very common problem with the Mossberg 715T is spontaneous bolt lock.  The Mossberg 715T, like it's 702 Plinkster brother, has a feature to lock the bolt in the open position for cleaning, reloading, etc.  It works by pushing the charging handle into the receiver, where a hook catches a tab.  It's handy for cleaning, and for rifle ranges that have "Bolt open when not in use" rules.  What happens on the 715 is that seemingly at random while you're shooting, the bolt lock will engage and the gun won't cycle.

I determined that the charging handle is the problem.  The bolt lock tab is part of the charging handle.  The stock charging handle is a fairly sloppy fit in the bolt, so it's got a lot of wiggle room.  What happens is that when the bolt recoils, the charging handle actually hits the plastic shell.  When it hits, the charging handle tilts ever so slightly, but just enough that the bolt lock can catch.  You can see the problem here:

And here's where it makes contact:

To correct this, I could have trimmed back the shell, or ground back the charging handle.  I didn't really want to do either, so I just made a new one.  Here you can see the change I made.  The original piece is on top, my new one on bottom.  The original handle is offset to the rear.  My new one is offset to the front.  While I was at it, I machined it with much tighter tolerances so it doesn't wobble as much.

Here's how it fits in the bolt:
Original

New:

 Now with the bolt all the way back the charging handle is no where near the shell.  Though I haven't put a whole lot of rounds through it, I haven't had a single spontaneous bolt lock since I made the change.