Thanks for reaching out Carol! I'm happy to say that all of CCI's 22 LR ammo should function without issue in your rifles. With semi-automatics you have to make certain the ammo will generate sufficient chamber pressure to cycle the firearm, but your manual action rifles haven't got that problem.
40 grains is the standard weight for a 22 LR bullet. When you go lighter, you get a faster muzzle velocity (speed at which the bullet exits the barrel) and resultant flatter trajectory (bullet flies straighter, which makes aiming easier). When you go heavier, you tend to get a subsonic muzzle velocity (quieter gunshot) as well as better long-distance performance.
If you want a good, versatile target round, I'd recommend the CCI Mini-Mag 40gr CPRN ammo. It's not built to deliver terminal expansion inside small game, but it's otherwise really high quality stuff: https://www.luckygunner.com/22-lr-40-gr-cprn-0030-cci-100-round
If you want 22 LR for hunting, then the Mini-Mag MeatEater 36gr CPHP ammo is excellent. That bullet is deadlier to small game, but you won't go broke firing hollow point 22 LR bullets for target practice: https://www.luckygunner.com/22-lr-36-grain-cphp-cci-mini-mag-meateater-300-rounds
If you want to see some truly flat trajectories that terminate in deadly expansion, then you'll love the "Stangers" 32gr CPHP ammo: https://www.luckygunner.com/22-lr-32-grain-cphp-cci-stangers-100-rounds
To be sure, you won't go wrong with any of CCI's ammo. Top of the line American-made stuff! And even if you go with a round nose bullet, you'll still have zero difficulty picking off squirrels and other rodents. Please let me know if you have any other questions!