You can inlet and bed your action. Also, while doing this, you can pillar bed your barrel and action and float your barrel. This is probably the best 'bang' for your buck without purchasing any parts. You will need:
1. a few different rasps for inletting
2. Some sandpaper with various grit, (start with 120 and work up to 600 grit)
3. JB-weld or some other bedding compound. A lot of folks swear by JB-weld
4. Some mold release. Neutral density shoe polish works very well for this.
5. Some shrink tubing or grafting tape to wrap around your barrel.
6. Some pillar hardware. These are screws, flanges and other stuff you can get at your local hardware store.
Instructions on how to properly inlet, bed and float your action and barrel are shown here
As to ammo, I have gotten my best results using CCI minimags and Aguila Super Extra, (both std and high velocity). Of course, I have gotten much better results with the more expensive ELEY, SKDG-JAG and other high end ammunition ... but that is a lot more money.