American or European magazine release?
With the American release, some magazines can "catch" during insertion when the sharp edge of the magazine catch catches on the top edge of a magazine, and even drags down the side until slipping into the magazine tube catch cut-out. This is sometimes a magazine lip burr issue, and considering it's a rental pistol, the magazine lip might've been scarred or bent just enough out of original tolerance that it was a hit or miss situation when it came to easily sliding past the magazine catch ... no pun intended. Also, the bottom edge of the catch might've been hit, and a small burr raised, during many rounds of rental use.
Another situation that sometimes occurs is when the front, sides or back of a magazine rubs against the inside of the grip frame at a "high" spot. Difficult insertions and releases can result. This can be caused by a slightly out-of-ideal-tolerance magazine body, perhaps resulting from downright abuse on the rental range. I've encountered and cured these problems on the ocaasional new magazine, though. Ever get a chance to watch an armorer take a plastic or leather mallet, or a file, to a high spot on your favorite new pistol magazine (metal tube)? They generally do it out of your sight if they're considerate.
The top round protruding slightly forward ... if it became that way from firing the round just before it ... is often caused by one of three conditions.
Damage to the magazine tube (the rental abuse thing again)
Weakened magazine springs, or debris somewhere inside the magazine, causing one or more of the rounds to be pinched/pressed against the inside of the magazine tube, causing lessened spring pressure to hold the top round(s) firmly against the lips.
Or, normal operation of the pistol.
When the slide runs forward and chambers the top round from a magazine, the next round can sometimes be dragged forward due to the friction of the bullet & case against the bottom of the slide. The larger the caliber & bullet, the greater the potential for friction. Ordinarily, this is reversed when the slide travels rearward under recoil, and then the next round chambers fine. If the magazine lips are out-of-spec, however, the round may not be held with sufficient pressure for proper feeding. Ever have a loaded round "pop" out of the ejection port under recoil? This is also why you sometimes see dimples, indentations, grooves and what-have-you in the sides of some magazines near the lips, to exert extra pressure on the case and prevent it from moving, especially under recoil.
Some welded seam magazine tubes were discovered to have less-than-clean weld lines inside the magazine tube, and the rims of the cases dragged, or even caught and hung up, on these weld lines. I recently cleaned up a similar problem with a few strokes of a file. The magazine weld was so bad at the bottom of the tube, the bottom rear edge of the metal follower hung up on a weld "lump" while loading the magazine, and the last round wouldn't go in no matter how hard the shooter tried to force it in.
Most of these things can cause the symptoms you've described.
Please forgive me if it sounds like I was lecturing. I didn't mean to. I just enjoyed learning these things back when a favorite pistol behaved in this manner, annoying and puzzling me ... and I enjoy talking about them ...
With the American release, some magazines can "catch" during insertion when the sharp edge of the magazine catch catches on the top edge of a magazine, and even drags down the side until slipping into the magazine tube catch cut-out. This is sometimes a magazine lip burr issue, and considering it's a rental pistol, the magazine lip might've been scarred or bent just enough out of original tolerance that it was a hit or miss situation when it came to easily sliding past the magazine catch ... no pun intended. Also, the bottom edge of the catch might've been hit, and a small burr raised, during many rounds of rental use.
Another situation that sometimes occurs is when the front, sides or back of a magazine rubs against the inside of the grip frame at a "high" spot. Difficult insertions and releases can result. This can be caused by a slightly out-of-ideal-tolerance magazine body, perhaps resulting from downright abuse on the rental range. I've encountered and cured these problems on the ocaasional new magazine, though. Ever get a chance to watch an armorer take a plastic or leather mallet, or a file, to a high spot on your favorite new pistol magazine (metal tube)? They generally do it out of your sight if they're considerate.
The top round protruding slightly forward ... if it became that way from firing the round just before it ... is often caused by one of three conditions.
Damage to the magazine tube (the rental abuse thing again)
Weakened magazine springs, or debris somewhere inside the magazine, causing one or more of the rounds to be pinched/pressed against the inside of the magazine tube, causing lessened spring pressure to hold the top round(s) firmly against the lips.
Or, normal operation of the pistol.
When the slide runs forward and chambers the top round from a magazine, the next round can sometimes be dragged forward due to the friction of the bullet & case against the bottom of the slide. The larger the caliber & bullet, the greater the potential for friction. Ordinarily, this is reversed when the slide travels rearward under recoil, and then the next round chambers fine. If the magazine lips are out-of-spec, however, the round may not be held with sufficient pressure for proper feeding. Ever have a loaded round "pop" out of the ejection port under recoil? This is also why you sometimes see dimples, indentations, grooves and what-have-you in the sides of some magazines near the lips, to exert extra pressure on the case and prevent it from moving, especially under recoil.
Some welded seam magazine tubes were discovered to have less-than-clean weld lines inside the magazine tube, and the rims of the cases dragged, or even caught and hung up, on these weld lines. I recently cleaned up a similar problem with a few strokes of a file. The magazine weld was so bad at the bottom of the tube, the bottom rear edge of the metal follower hung up on a weld "lump" while loading the magazine, and the last round wouldn't go in no matter how hard the shooter tried to force it in.
Most of these things can cause the symptoms you've described.
Please forgive me if it sounds like I was lecturing. I didn't mean to. I just enjoyed learning these things back when a favorite pistol behaved in this manner, annoying and puzzling me ... and I enjoy talking about them ...