Yes, some of the early Browning High Power .308s and .243s were on small ring FN M98s, before they used Sako actions for those calibers. At least they were SR externally, I have heard that they were also true small thread, but some claim that they were large thread simply ground to small ring externally. I have one in .308, but have not pulled the barrel to check. And those SR FN Brownings had the nearly flush bolt stop, this rifle does not. And the Brownings did not have the thumb notch, either.
The triggerguard looks like a kar 98 to me, which were small ring/large shank receivers. Of course that TG may not be original to the action.
Or it could be a small ring Mexican M98, the left receiver rail looks a bit higher than on a std. 98. Not sure if the early transitional Oberndorf commercial SR 98s shared that higher, angled "loading ramp" left rail, or not.
It is an nteresting rifle, anyway.
Last edited by redoak; 01/14/21 12:09 PM.