I have on eor two of those...I think just one...but I remember naming it..."The Mule" because it seemed to have a particularly nasty kick compared to...

If I remember correctly, because I had the same problem as you...not cycling the less powerful shells...there's a set of rings...friction rings under the forearm that you can use to adjust the gun to cycle with less powerful shells. Again, if I'm remembering correctly the process to change them is relatively simple.

Once you make the adjustment it will still shoot the more powerful shells but the slide hammers the gun pretty hard and you likely don't want to shoot it like that a lot.

A search of the net might...would probably...let you know how to make this change.

Well...here's a video...there's probably better ones out there??