Seems pretty normal, there have been a few people who converted them to 9mm.I wonder how the barrel is attached, maybe easy to make a 9mm. I believe 9mms work in the mags. I see the bolt is rimfire style using the bolt handle for the lugs.
The bolts actually a 2 lug, bottom lug on the rear of the bolt body, and the handle root. tho I dont know how much the root bears on the receiver.