Firts welcome to the forum
Now what you are doing is actualy quite a waste of time, as you have found out the very first thing that you want/need to do with any new firearm is field strip and clean it, relube it and reassemble.
Now if you want to sit and rack the slide over and over then you may relax the springs a bit and smooth the rail to frame fit some, but trying to chamber rounds by hand to simulate actual firing is not really going to work.
First its not unusual for a new firearm to take 200-300 riounds to fully settle in, this for semi autoes, some take even 500 rounds to become relaible!
typically(and every weapon si different) things to look at is, first ammunition selection, use a round nose FMJ for breakin, its normally going to feed better.
second if you are hand releasing th slide it should be stoutly pulled all the way to rearward and let go of, do not ease or ride the slide foreward, if using the slide stop then keep the hands ,fingers away from the side of the slide so as not to slow it down.
finally in a ultra small wepaon like the 738 its very important that you have a firm stance and grip on the weapon as it has somethign to work aaginst.
hope this helps you some!
MY best advice is to just take the weapon and shoot it a bit before depending on it as self protection.
