Split Fiocchi Brass

[logik1]

Was just at the range shooting my brand new HK USP in 9mm. I'd brought up a few different types of ammo to see what it liked best, and I noticed that some of the Fiocchi casings were coming out with a split from about half way up the casing to the rim. They were 115 grain hollow points - has anybody else had this problem? I'm assuming it was the ammo, because the Winchester cartridges weren't doing it, and neither were the 124 grain Fiocchi FMJ's I brought up.

???

 

[Thamok]

Do a drop test in the barrel of the pistol - does the HP of the Fiocchi engage the lands a weee bit early? This could be increasing the preasure of the Fiocchi ammo.

Im not familiar with leade that HK uses on there USP so it's just a guess.