Yikes;I'll save this one for the next time someone tells me I'm too fussy about backstops.bare with me, this does have to do with the best WW2 cartridge
I was working in Las Vegas about 5 years ago and my associate received a cell phone call from his wife
the Henderson Police were at their door with a warrant and the REAL CSI Las Vegas was with them
when he got home, the police asked him if he owned a Mosin Nagant 91/30 - and he said yes
a home owner in Henderson had complained that a bullet came through their Livingroom wall, missed their kids and imbedded itself in a wooden stud in their garage
it was a 148 gn, .310 diameter bullet, commonly used in the Mosin Nagant
the police had a warrant to search his home for a Mosin - CSI had lasered the .30 cal hole in the end destination and found it came through his fence from his bedroom wall.
the Police and CSI accompanied him into his bedroom, turned on the laser and it went through his fence, through his bedroom wall, BUT THEN they noticed the laser also illuminated a .30 cal hole in his bedroom closet and HIS kids room and they found an entrance hole in the outer wall of HIS garage, going out into the desert beyond Henderson.
SOOO - someone out in the desert East of Henderson had shot his Mosin, which traveled over a mile, went through my associates home, through his garage and two bedrooms, and across the street, through another home and finally imbedded in a wooden stud in THEIR garage.
One of the first times I shot mine - my first gun by several years - I was out in a field in the Yukon, blasting away at various trash left there. At one point, some friendly locals arrive with various guns and targets, including a couple of these things which they offered to let me use:
They looked and felt rather sturdy, made of heavy steel plate at least 3/8", maybe 1/2", and I was grateful for a target I could actually see if I hit or not. So I set them up at about 100 paces range and carry on... A few dozen rounds later, WTF is going on? Did my aim suddenly worsen? Is the batch of ammo at this end of the spam can all duds? Why am I not hitting the damn things? I call "cease fire", hike over to the targets... and discover them full of holes, all over the flappers and some through the hoops (even thicker steel IIRC) as well. They didn't even flinch when hit. I bring them back to the locals, obviously more experienced shooters than I, but whose eyes went just as wide when they saw their targets. They burst out laughing and refused my offers to buy them new ones.
Perhaps it was overpowered for anti-personnel use, but I imagine there were often enough scenarios where a squad of infantry with MN (or similar full-sized rifle) happened on a milder hard target - an armored car or halftrack, for example - and blew a whole lot of small holes through it that a more "right-sized" intermediate round would not.