Sum1_Special,
If you ever do decide to get another gun, an old single-shot shotgun would be perfect for you. I have a 30 year old H&R 20 gauge that I use for snakes and various pest. If you look around, you could find one for about the price of your pellet gun.
If you stay with the Mosin Nagant, get expanding bullets if you can find them. I've shot a few objects with the FMJs in a Mosin Nagant only to discover that the hole was smaller than the bullet.
Also, my old FMJs had a metal core that are for sure going to over penetrate and/or ricochet.
Be careful.
JRLaws