^^ Totally recommend this. My groups, even with top-shelf ammo, shrunk measurably when I used the DIP bottom metal. If you can swing it, here's a few other mods that'll help:

1) Rifle Basix SAV-RAT trigger. Not really a necessity, but IMO it's a nicer, crisper trigger. The Accutrigger is nice, but the RB is even nicer.

2) DIP trigger guard w/ overtravel stop. Really cleans up the back end of the trigger pull.

3) Loctite or nail polish. Not sure if you've done this already, but some purple loctite or nail polish on all of the scope mount-related screws will help ensure it's not moving at all.

4) Torque wrench / screwdriver with in/lb setting. Savage action screws on rimfires are set around 15 in/lb, I believe. However, ask anyone here, and they will tell you that you can greatly improve accuracy with a little bit of changing the torque on the action screws. There's a bit of a process that I'm sure you can find by searching, but it's worth it.

5) Make sure the barrel is free-floated. Savage rimfires are pretty good about having the barrels free from the factory, but you do get the occasional burr / splinter that presses on the barrel. Do the dollar bill test, and if it's tight anywhere, put some rough-grit sandpaper around a 1" dowel and open up that barrel channel.

6) Based on personal experience, Savage rimfires seem to like a bit more shoulder than other rifles. I guess the forward pressure helps them. I've seen it improve groups in both wood and plastic stocks.

Other than what's already been suggested....nothing makes up for practice. Get out there and start putting rounds downrange, and you'll see your groups improve.