I too would suggest mag lip adjustment . The newer mags w/ plastic followers almost always need some " tweaking " . I do trim my cases to 1.145" , seat HBWC's flush & taper crimp to .369 . Seems to work for me . Stock recoil spring is 8lb & as long as gun is in stock configuration should function . Wolff does make a 7lb spring . Just checked 5 of my mags & rear lips run from .328 to .348 . You could also try replacing mag springs on the problem mags . I'd also check to see if mag lips or ejector are dragging on the slide . Low recoil impulse + inhibited slide travel = FTF . IMHO 1) Load too light , 2) Recoil spring too stiff , 3) Slide dragging on something impedeing full travel , or some combo of these . That & round not being released from mag early enough to chamber fully . Hope this helps . I'd not go hotter than 3.0 BE on your loads . My 52-2 prefers 3.1 - 3.2grs W231 , with 3.6grs VVN340 running a very close second .