got a slip-on pad- one of those dead cheap ones from cdn tire/Walmart- mine was 12.95- it's nothing more than a recoil pad with a sleeve- you need to cut a notch for the sling swivel before you put it on- I can't see why that loop would be cutting your finger unless there's a rough surface inside the loop- if there is, you can fix that with a dremel- mine is solid blue, not case coloured like yours- and I don't wear a ring- that could be it as well- the top/bottom edges of the ring are digging into the finger under recoil-there's something funny still-that lever SHOULDN'T move under recoil- it almost sounds like it's not locking up properly-it's really a job for a smith , but if you have a LOOOONG handled screwdriver, you can take the buttplate off, then the stock screw( it's a blade btw) and take off the buttstock- then you'll see a screw at the back of the action-open the action and it should be sloppy for the first 3/4s of the stroke but real tight almost to the point of you can't close it for the last 1/4 stroke- that's the bolt camming into the back of the action- if you can't close it, that screw is too tight, if it's too loose it'll just flop- or you can let a smith do it- get one that knows what he's doing like barry over at bits of pieces- it's not an action for everyone- you should also check to see if your stock screw is tight- like I said - NOTHING should move under recoil
now that I can see your rifle, the first thing I notice is there's a considerable WIDER gap between the stock and the lever- mine butts up against it-tight as a drum- that's either lock-up or a loose buttstock-schematics for the 99-c are on line