Here in Amarillo TX I can buy all the 20 gauge I want. But I can't remember the last time I saw any 410 shells on the shelf. I've ordered it online but sure haven't seen it locally in a long, long time.
I was gifted an old Mossberg, bolt action .410. The main purpose was for turkey hunting.
I could find some 2.5" #8's, but 3" with ANY shot size are absolutely nonexistent! 😖
I ended up having to purchase two 5 packs of Feferal 3" .410 with #9 TSS! That crap is $6/shell! 🤯
P.S. - but it is a blessing to be able to find 16 gauge ammo again. Selection is kinda slim, but bullets is bullets!