On Sat, 10 Mar 2018 08:53:57 -0800 (PST), "
wrote:

I have three framing nailers that I use in rotation, or as needed. Two different model Hitachis, one Bostitch.

All of them shoot from 6d (2") to 12d (3 1/4") by just changing nails. Same magazine.

Most folks have no idea what is available as far as pneumatic nails go, or what nail sizes are at their gun will shoot.

You're right - I didn't know. I just looked mine up (Hitachi NR90AE).
Apparently it'll do 2" to 3-1/2", 21-degree, .113" to .148" nails. I'd
always used nails on the larger end of the range. It looks like it'll
save me the price of a new siding nailer (my eBay special, Senco is
acting up). I may have to hire the job out, though. :-( I can't
postpone it another year with a garage full of siding. Getting old
isn't for sissies.

Nails not commonly available but easily ordered would be nails with certain glues, galvanized or plated, ring shanks, chrome plated, stainless Steel, and any combination.

The ones I need (I think) are on Amazon. Not sure of the length...
https://www.amazon.com/NailPro-Inch-0-113-Stainless-Nailers/dp/B00ANTKZSU/ref=sr_1_1?ie=UTF8&qid=1520702519&sr=8-1&keywords=stainless+nails+for+nail+gun+21-degree

g
About ten years ago I put a clay tile roof on a house (tiles about 90 years old, hand thrown) and the screed attachment spec was to use 8d stainless ring shanks nails. Took about 2 weeks to get them, but no problem once ordered.

Thanks to all for educating me!