I picked up a Hopkins & Allen 900 series that has been rebarreled with a Remington matchmaster Barrel. But the firing pin hits in the center not on the rim so this has a center fire link in it anyone know the hole center to center on a rim fire link or have a link thanks ken

The one I have is .945 I was thinking that it would be shorter not longer Thanks Ken

I went the opposite direction on a 922 last year.  I changed from .32 RF to .32 S&W.  Don’t overthink it.  A new link roughly the same shape as the old one with the holes closer together by the distance you need to move the pin location is good enough.  The .22LR rim diameter is 0.278”, so 0.139” minus 1/2 the diameter of the firing pin will move it to the right location.  Moving the hole 0.120” to 0.125” is about the range.  You might be able to redrill the existing link to get the hole in the right spot.  Moving it down that much might need some adjusting of the extractor where it hits the bottom of the breech block.

Did you take the block and link out of the rifle to have a look at it?

Some of the 922's have a link in them that has two holes in them. One to position the block for use with RF rounds.
Change the link & pin over to the other hole position and it will raise the block for CF rounds.

If the rifle was orig a 32cal and has the 2 position link, for using 32RF and 32CF (32 Colt),  the RF position will very likely (if it's there!) be usable for the .22rf conversion.

You may have to enlarge the diameter only (not the depth) of the rim recess cut where the tip of the RF firing pin strikes so it does not strike the edge of the bbl face as well as it was intended for the slightly larger 32.

The 922 was also made in 38cal RF/CF with the 2 position link.
If the rifle was orig in 38 cal, changing to a RF position would place the firing pin strike too far down to be usable with the .22 rf conversion I believe.

Nice little rifles.