Hammerli Air Rifle Trainer For Swiss K-31
 

Anyone have any experience with one of these. I was reading about this unit in a book I bought on airguns and it seems interesting.

I found quite a few references on the web regarding these, I'd be curious what they sell for in good condition. Seems like an accessory
I'd enjoy having for one of my K-31 rifles. Not sure how mainstream the caliber is. Didn't bump into one for sale.

Here is a decent reference to the device: http://www.network54.com/Forum/40594...insert+for+K31

Jerry