A relatively common mistake when reassembling the Hi Power pistol appears to be accidentally replacing the recoil spring guide upside down. It can appear to be in place and the pistol can actually be reassembled with it incorrectly installed.
This view from the bottom shows the recoil spring guide as it should be. Note that the flat side of the recoil spring guide facing away from the barrel.
This side view shows the same correct installation.
A Hi Power with the recoil spring upside down can be very difficult to field-strip in some examples but the slide stop lever will never have downward spring-loaded tension, which it would have were the recoil spring guide correctly installed. In other words, the slide stop lever will just loosely wiggle up and down. In a Hi Power with the recoil spring guide properly in place, you can lift the slide stop lever and will feel a small amount of spring tension in the downward direction while doing so. When you release the lever, it will snap downward. If the recoil spring guide is upside down, it may fall down or stay as is…though a slight touch will almost always cause it to fall.
If a Hi Power is shot with the recoil spring guide upside down, the usual result is to break the guide. The ring on the recoil spring guide that surrounds the slide stop lever shaft almost always cracks and after as few as but a single shot. What happens then is that the slide stop lever engages with rounds still in the magazine and in some cases, just falls out of the pistol.
Here is just the guide and barrel. The recoil spring guide is upside down. This is the WRONG way to have it when reassembling the gun.
This is CORRECT.
Best.