I figured since they're cut down to length, they wouldn't need to be pinned? I only ask due to the potential need to clean or rebuild magazines.

They dont need to be. A 15/20 or 15/30 needs to be so that it cannot be taken apart and reversed and hold more than 15 rounds. If you take apart a 15 round magazine, you cannot mod it to hold more than 15.

The stubbys are all pinned. The curved ones can hold up to 19 rounds and the really short 5 or 10 round model is also pinned due to most going to hunters who need permanently modified mags to keep the peace with local DNR.

my apologies. I didnt realize this was the vendor board (came through most recent) and thought it was a generic question if a short factory mag needed pinning or not

No worries. All are welcome here