"Seemed quite hot" is not a standard unit of measure.
Is the target mount to a cardboard backing or free hanging? If just blowing in the wind the holes will be jagged or keyhole
Based on the minimal information provided, the holes appear to be normal for anything but a wadcutter or semi-wadcutter with a sharp, well-defined shoulder.
The bullet is a 9mm FMJ 124gr FIOCCHI. The gun is a G17 3rd generation. The target distance was 25 yards. Unfortunately I didn't have a chronograph with me but the load seemed pretty hot...
I have a few old Mosin rifles that keyholed because of a bad crown. A simple counterbore fixed the issue.
After having seen a lot of sideways bullets, I can positively say that the holes above are quite normal.
The other issue is the quality of the cheap paper they use for targets. Shoot at a good boxboard or Masonite board and the holes won't look like that.
Fiocchi ammo most often is on the warm side.
At the Trap range, when someone is not using the proper ammo,
one of the regulars, will shout, that sounds HOT.
Then they are removed, unless someone gives them ammo to finish the flight.
If someone tried to remove me from the field because they didn't like the sound of my shells there would be a problem.
The sound gave away the fact that they were shooting ammo,
that was not allowed on the range.
The RO either asked others to help with proper ammo, or removed them.
Nothing like those new shooters, with auto loaders, that would chamber a round, with the barrel pointed down, and blow up the concrete.
My 100 year+ old revolver shooting 32-20 WCF lead round nose. Usually this gun produced nice holes in Birchwood Casey splatter targets at indoor range (no outside wind).
This target looked like keyholing to me but others said look at your cardboard backer....it is shot out totally in the main center section so you have nothing but air behind your stapled target.
Lo and behold....they were right! New backer, nice and stiff, now round holes.
I learned something.
Do you think these marks are signs of unstabilized bullets?
They are commercial FMJ bullets. The load seemed quite hot.
Fiocchi ammo most often is on the warm side.
At the Trap range, when someone is not using the proper ammo,
one of the regulars, will shout, that sounds HOT.
Then they are removed, unless someone gives them ammo to finish the flight.
Do you think these marks are signs of unstabilized bullets?
They are commercial FMJ bullets. The load seemed quite hot.