94AE rifling vs. bullet weight

I just purchased a new 94AE from a local gun store. I did the usual condition checks. I asked the clerk about ammo. He sold me a box of 265g Leverevolution. The box states its for a 1 in 20 twist or faster, while slugging the barrel I calculated it to be a 1 in 38. So I checked and sure enough its 1 in 38. I was aware of the slower rifling in some models, but in my research before purchasing the only info I found was that the slower rifling lacked the ability to stabilize heavier bullets( being 300g or more). The 265g bullets certainly does not fit this description. Why did these loads get labeled like this?