.22 or .17 for warehouse shooting Sparrows and Pigeons?

Another thing to try is lightest leadfree pellets, they are so light they lose power much faster than lead pellets so it's safer while can maintain 600fps without being too dangerous.

Lead free pellets are normally zinc. Zinc is a very hard metal. I believe zinc pellets would be more likely to pass through and cause damage to sheet metal and other ''things" in the background than a soft lead wadcutter.
 
Another thing to try is lightest leadfree pellets, they are so light they lose power much faster than lead pellets so it's safer while can maintain 600fps without being too dangerous.

Lead free pellets are normally zinc. Zinc is a very hard metal. I believe zinc pellets would be more likely to pass through and cause damage to sheet metal and other ''things" in the background than a soft lead wadcutter.


you are correct that they are a bit harder but not by much, I can easily deform the skirt with my nail still. While what you said might be true at closer range say 20 feet but at 30-40 yards it will have less energy. I’ve done penetration tests with both pellets shooting at same setting the lead free one loses a ton more steam and barely penetrating the wool block vs the lead pellet still buried itself deep into the same wood block at 30 yards. Up close the penetration looked identical for up to about 20 yards. So from my own test in confident that lead free pellets are much safer especially pass 20 yards, leadfree pellets are all I use for the house sparrows in my back yard. However I would not use them on squirrels unless it’s super close and headshots only due to they lost of energy and penetration capability down range.
 
@qball Thanks for that additional input. I had considered lead free for shooting pest birds. Primarily starlings but crows and pigeons are on the list also. I will have to take another look at them and a scrap piece of tin roofing.


crows a bit tougher so you might want to get a low power 177 for inside and small stuff while keeping your 22 for crows and longer shots. 


I always test penetration/damage with every ammo/tune so I know the potential damage.