We still need to know whether you are neck sizing(NS) or full length(FL) sizing. If you are FL sizing, try this.
1. Take the die out and back the lock ring way off.
2. Raise the ram all the way up.
3. Insert die and lower it to make firm contact with shell holder.
4. Lower ram.
5. Screw die IN another 1/4th turn.
6. Raise ram to die and put firm pressure against the die.
7. Screw lock ring down against top of press.
8. Tighten lock ring set screw. Unless you have a Lee lock ring.
9. Size a case.
10. Chamber the empty case and see how it goes.
If it chambers easily, you're good to go. If not, the die is either too big in diameter, or the headspace in the die is too long, or the top of the shell holder is too thick.
The "grooves" in your barrel should be darn near .204". The "lands" are the rifling and stick out. That is the spiral you see when you look down the barrel. It is what grabs the bullet and gives it spin. To check for bullet seating depth, try this.
Take an empty case. Cut a vertical slit in the neck, barely into the shoulder, with a hacksaw. Barely seat the bullet you want to use in this case with your hands. Chamber this round in your rifle. Eject it with your hand covering the ejection port. Take it out and measure it from base to tip with your calipers. This will give you MAX OAL (over all length) for that bullet. In other words, this bullet is touching the rifling. Now you can experiment with different seating depths. I've found that my rifle usually gives best accuracy .030" away from the rifling. But you'll just have to experiment as to what shoots the best out of your gun. This method works very well and you don't have to waste money on a Stoney Point gauge.
This should be in The Handloading and Reloading Forum.