The Wiki article is actually pretty good.
6.5×52mm Carcano - Wikipedia, the free encyclopedia
Now several things are going on here not that are not covered.
1. The Carcano in 6.5mm never got a Spitzer bullet. The heavy round nose bullets loose velocity quicker than the Spitzer bullets meaning impact energy goes down quicker with increase range. This is a problem for the Carcano as it is one of the two weakest 6.5mm rounds to begin with.
2. While the Carcano might be OK out of the long barrel the short barrel carbines cut the velocity to under 2200fps which further hurt impact performance. It also doesn't help trajectory.
3. Italian Army compounded the last problem when they fitted fixed back sight to the 1938 models of the rifle.
4. As a rifle the Carcano was OK as it was. It gets a bad reputation in the US Because at the time (1950s and early 60s) many US gun owners were interested in converting surplus military rifles to hunting rifles using standard US rifle calibers. The Carcano, while strong enough for it's original cartridge, wasn't strong enough for some of the commercial hunting cartridges. The magazine system was also hard to convert. which leads us to...
5. Gun was loaded with a 6 round enbloc clip.
The sheet metal clip went into the rifle and stayed in the magazine until the last round was chambered at which point it fell out the bottom of the rifle
You couldn't "top up" the rifle, ie, if you fired 3 rounds you could not add three more rounds. you could either carry the rifle with just 3 rounds in it or eject the partially filled clip and put a new full clip in the gun. Of course the partially filled clip will NOT hold the 3 rounds in the clip and you will be holding a sheet metal clip and 3 loose rounds. Large hole in the bottom of the rifle was
supposed to let in dirt. I don't know, wasn't there, never used one.
BTW I like the 6.5mm caliber, I had a 6.5mmX .308 rifle built for target use before the .260 Rem was a commercial cartridge and also had a rifle built in 6.5mm Rem BR, 308 case shortened to just 1.5 in long instead of 2in (or 51mm), which is where my forum name comes from. Some forums will not take the period between the 6 and the 5 in 6.5
This last rifle, while not a particularly good military round (a bit fatter than 6.5 Grendel) is one of the most accurate rifles I have ever fired. A heavy Hart stainless steel barrel gets a lot of the credit along with the gunsmith who built it.