Those bullets are hard cast plated. The load data needed is generally some place between lead and jacketed. Most of the time you can get by starting in the middle of the lead data and work your way up to not more than mid-range of the jacketed data.
If your slide is not going back far enough to pick up and load the next round when firing, you probably are using too light a load. When this is the problem you are having it is time to load some more test loads. Increase in 0.1 grain increments. I would tend to want to stay at or below 4.2 grains. This is only a guess on my part. Load 5 and no more that 10 rounds for each step you are going to try.
If you are having a problem with the round chambering that is something else. What is the Over All Length (OAL) of the rounds you have already loaded that didn't work?