synical Not knowing your round count do you use the slide release or sling shot it. Try the release only . Maybe run it for a while with one round down to and see if that helps. May just need some run time to loosen up. If you have some fitz metal polish do a bit of polishing on the ramp too.
I probably have at the most 70 rounds but yeah I sling shot it. And i keep it lubbed pretty well i have been working it back and forth and its helping i think i just need to go shoot it some more!
If you can pick up some magtec ammo try there 95gr fmj ammo. They do run well in mine. Winchester white box is one brand I will not use. Seem many people have problems with there white box ammo. I only have 50 rounds fired so far but all ran 100%. Also get an old inner tube for a mountain bike. Bike shop give old tubes away. Cut atleast on piece for the grip to aid control. I use 3 pieces, 1/4", 3/4" and full lenght cut to fit. Really does help to keep a tight controled grip. Some times even a second seasoned shooter can help. Good luck.
If you are having problem with any ammo feeding in your 738 I suggest you Google "taurus tcp 738 mag lip" you will find an easy fix that I tried and worked great. I have no issues now with any ammo I have used so far. I never thought I would like a Taurus but I was wrong.
Rain, snow or sleet.... Mud, sand and dirt.... My GLOCK will work ;)