As others have said, we need more information...
A few initial thoughts;
1. If you are new to reloading, you might be better off starting with straight walled pistol cartridges, like the 38 Special. That's usually the better place to learn. Starting with auto pistol cartridges, like the 40 S&W, require more knowledge and experience, and can get you into trouble very quickly. If you don't want to heed that advice, then see Point #3 below and also be extremely careful with bullet seating depth. The 40 S&W has a small case and seating bullets too deep will cause an over pressure condition very quickly. Also, learn to apply the right amount of Taper Crimp, so you don't run into bullet setback...which is another problem you don't want to have...it's no fun losing a hand...
2. Hopefully, you are loading on a Single Stage or Turret Press and NOT a Progressive. If you are loading on a Progressive, and you are a beginner, you are usually asking for trouble.
3. The rounds that got jammed in the barrel and didn't fire...sounds like you need a Cartridge Case Gauge, like this one from LE Wilson...
https://www.midwayusa.com/product/276502/le-wilson-max-cartridge-gauge-40-s-and-w
I believe the 40 S&W, like the 9mm headspaces on the case mouth, so the gauge is essential. These gauges are something you should have for every round you load anyway.
4. ALWAYS reference a few Loading Manuals and work your way up from the lowest charge to the highest and test each round for Over Pressure. When you notice over pressure STOP. Drop to the last load that didn't cause the over pressure situation and that is the highest charge your pistol will tolerate. If you don't know how to recognize over pressure, STOP RELOADING, and re-read your Loading Manual instructions in this area. Another good point when loading for semi autos...you want to end up with a load that works the action properly and does not batter the frame.
Point #3 might solve your problem, based on the limited info we have. Please note the warnings I've given you and stay safe.
Let us know how you make out...