You can cut through most mat rolls up to 3 mats with a good thin-ish sharp khukuri, any number of fine Cold Steel products, and I have done so with the Cold Steel Imperial katana.....sharpness, angle and speed all play a factor, so the AK should not have an issue.
That said, I do not know of ANY sensei worth their salt that would allow this item in his/her dojo. Tameshigiri is a time tested way to check ones skills, and introduction of non-traditionally mounted swords is viewed within the JSA community as the unwanted by-product of the West creeping into a traditionally asian Martial Art.
Best Regards,
STeven Garsson, Nidan, Muso Jikiden Eishin Ryu Iai Heiho