What type of ammo is this?

[porcupineballs]

I dont shoot rimfire at all, but I was researching some things in regards to 5mm rimfire rifles, and came across this picture. What is this ammo on the right? The one right next to it is 5mm I think, but Ive never seen anything like the one on the far right.

[DaveInOroValley]

5MM Remington is google search by image best guess

https://www.google.com/search?tbs=sbi:AMhZZisWQb2iYtNnsCURv-9BYSvWZz3y43Pyj1Xew9RXG0pfwOIqtCoaWufiPEGnfoh7EoLR6W28r7AF-_1SIqTth_1_1yVTFUSUwU0LN9LSR558jf2l-PtUtA1tInvdxqcqMtPTms5thhmnlh_14NsRSzG56uykVc1oTI4GHlLbnqgkJ510E_17QvK9l-1j9cdlAbinQI3wUrs_1wn1p-HGxs2tcVdhefi2AG4q6gA-X4xETbKB3-IxKMSwAlCjwTTRLl-sZBtpTVu24bfxXcEVczWxe6tYxDn5MufPr6v1A7UPfvuCCuEfUP9_1XsNW7uLMD0hU0evHQbTD4ZVCN1ug9GcHTbfG_1o3IB-5w&hl=en

[porcupineballs]

5MM Remington is google search by image best guess

https://www.google.com/search?tbs=sb...1o3IB-5w&hl=en

I think the original pic goes .22lr, .22wmr, .17hmr, 5mm rem, and then whatever this mystery round is on the right based on the info below.

[JAGGUY]

256 Remington magnum

[Delta Rose]

My guess is .256 Winchester Magnum.

[porcupineballs]

Ahh it does look like .256. For some reason it looked like a big rimfire cartridge to me, but it must be the way the pic is focused.

[plumbum]

I kee hoping someone will blow out those .17 WSM nail blanks are o something a little heavier - even straight wall would be cool.