Where have you been?
I hate to sound an arrogant tw@t ...
... but many many years ago ... must be way over 10 ... my mate bought one in 0.22.
Cocked awful ... galling issue on the articulated cocking lever. I polished that up and added some grease and that was easily sorted. I squared off the spring and added a top hat and a decent rear guide. Dead easy, kitchen table tune up.
That little gun shot superbly. I did some investigations and it seemed like the 99s, in 0.22 anyway, were basically perfect for the UK 12fp market. The swept volume of the rifle etc is running at it's design efficiency at about this power level.
I was ranting about this little gun all those years ago but no one really seemed interested. Everyone was raving about the 95 as a light weight break barrel springer.
The 95 tuned up and running at it's best is more like a 15fp+ rifle. The 99 doesn't have to be crippled to run at 12fp. It is running at it's best at 12fp.
It has the same quality Rekord trigger as the rest of the top end HW's.
All these years later Sandwell Field Sports tidy up the insides of a 0.22 99, shorten the barrel and put a silencer on the front and they have created the new Messiah.
Since then this little HW has been the talk of the town with everyone raving about the SFS gun ( The Imp ) with others commenting on how easy it is to tune and shoot well.
The galling issue with the cocking has been sorted by the manufacturers now.
In 0.22 it's a dead easy gun to get shooting sweet as a nut and it will shoot very accurately with a great trigger.
In 0.177 it is probably best at a lower level of about 10 - 10.5fp but that's typical of lighter weight break barrel springers. Bigtoe, Wonky and the other pro tuners will have more knowledge of how to get the 0.177 shooting very sweet.
Loads and loads of threads on here in the last couple of years raving about how good they are. So a search will tell you all you will ever need to know.
Plenty will come on and tell you how good this little rifle is.