Thread: 7.62x39 rifling groove diameter

My Ruger ranch rifle has a .311 diameter grooves according to the internet.
I have projectiles that are .310. It seams most projectiles for this caliber are this size. I have two neck resizers .308 and .311 (collets) in the Lee dies.

I have a couple of questions if someone would be kind enough to answer.

1. Should I try and find and use .311 projectiles (303)?
2. If using .311 collet with a .310 projectile will the projectile be held in the neck of the case well enough?
3. Should I try the .308 collet and try and get a pill in there. Hopefully, not damaging the brass case?
4. Any information you have regarding reloading this caliber would be appreciated. I was going to use CFE black. However, I have to travel to Auckland to get it. A local is selling ADI AR2207 powder. And it $20 cheaper. Any thoughts to save me time and hassle would be great.

5. Any ideas on bullet creep and the distance off the lands. For improving accuracy.

To anyone that answers my questions. Thank you in advance for sharing your knowledge.

Kind regards, Brent