Went to the range today with my new-to-me 52-2. Ist magazine, 5 HBWC's, fired flawlessly !!!
2nd magazine, 5 HBWC's, #1 fired, #2 fired, 3 fired, 4-jam.
Tried it again, same results, always a jam at #4. Tried various brands of ammo, always a jammed #4. Went back to 1st magazine, no problems.
Back home, loaded 2nd mag with 5 snap-caps, hand cycled 3 rounds, again, #4 jammed. Swapped out the mag springs, same result ! Loaded 5 again, 3 cycled no problem but I noticed that round 4, still in the magazine, rattled, ie no spring tension. To make a long story short, the little cross bar which fits into the mag follower and rides in the groove in the mag body was a few thous too wide, and was hanging up on the frame cross piece (where the grip screw attaches) just when round 4 was fed upwards, the cross piece would bind on the frame. Filed a few thous off the ends, reinstalled it,loaded up the snap caps, no problems !!!