If you do a internet search there is very little info on the Blaser 820.
I do believe it is a falling block single shot, and as such would be a strong action.
Barry Browning has one on consignment on both GunBroker and Guns International, that might be your friends.......
https://www.gunsinternational.com/g...-06-looks-new-.cfm?gun_id=102361966#lg-2Hollowell has a Blaser 821, which from what I can tell is a step up in the quality of the wood and engraving, as well as an 822 and an 823 which are pictured at the bottom of the link below.
https://hallowellco.com/blaser__BL_821%20%20Luxus.htmI have had two of the K95's and have found them to be quite enjoyable.
Tell your friend good luck with his sale.
Ya!
GWB