.22 LR question

[BigEd63]

I've never bothered with a .22lr past 100yds and if i did I don't recall.

One thing I've noticed over the years is that .22lr ammo has the overall Ballistic Coefficient of a rubber brick considering it's weight and profile.

So use whatever standard to high velocity ammunition your particular rifle likes the best.
My current long range .22 is a vintage Mossberg 144 bolt action. Using Aquila Interceptor solid point.
Of course that's "unobtainium" currently.

[Garand]

My bragging shot with a .22 is at 75 yds on a steel 10" tall gopher with a .22 LR Kimber conversion kit fit on my Series '70 using CCI Stingers. Steel gopher shoots are a hoot!

[Tugaloo]

The 22 RF's headspace is set by the thickness of the rim. SAAMI's specification for the .22 RF long rifle is on page 13 at the link below.

https://saami.org/wp-content/uploads/2019/06/ANSI-SAAMI-Z299.1-Rimfire-2015-R2018-Approved-2018-06-13.pdf

Per SAAMI, the rim thickness is .043" to .036" (1.09mm to .91mm)
This is one of the reasons accuracy can vary by the ammunition manufacturer and the firearm manufacturer.