Glock 40 MOS & 357 SIG

I bought a G40 (10MM) to shoot 357 out of it. It is a LWD barrel. I have read that people have had no problems doing this. I however, get FTF. It seems the nose of the bullet goes splat right into the feed ramp. This simply does not compute with me. I also notice FTE where the case literally gets caught long ways between the chamber and slide. Is there a trick to making this more reliable? It almost seems like the ammo is not quite strong enough to operate the slide. These are 124 grain...

Glock 40 MOS & 357 SIG