I'm glad you got it back. What was the total time it was gone? Have they fixed your issue?
I believe they received it on 3/17, got it back 5/5/2014. I have fired about 50 rds through and the mag stays where it is. ( problem-- would fall out with each shot).
They had it about 44 days+/_, but it was done and ready to ship on 3/25/2014. Would I have liked to get it back sooner-- yes, but it is not a duty,carry, competition weapon at this time, As you saw in the earlier posts they are trying to improve, sometimes it takes time to work out the "bugs" I had my carry gun so it was not a problem for me. 1-day, 1-wk, 1-mo, really did not matter. I will be getting another MP 40 for my wife on Monday.
When they had my brand new ,out of the box 629, for months ( in 1994) that was a problem because I could not hit anything off a rest with my proven target loads, and the first time I sent it they put the sights back to center and sent it back. Eventually they replaced the frame which had been drilled off center, they kept me informed with calls, not cylinder, not barrel, etc. I took it from UPS, went into house , loaded it, 240 fed JHP, went out to my range, set up the target @ 25 yds, all 6 DA,off hand, in the black, ( 5" diameter target). I still have it, millet night sights added, it would shoot 1 hole groups @ 25 yds back when I had young eyes, it would do it now with some one else behind the trigger on a rest, 240 XTP.
So I guess you have to take the Good, Bad, and Ugly together. Be Safe,