#2999 Savage Short Action Varmint/Tactical with or without Accu-Trigger. Fits the short action "two digit models" only (Model 10, 10GY,11F,12,16,etc.)with heavy contour barrel and top loading internal magazine, with action screws measuring 4 1/4" center to center only.
As long as he has the above, and a staggerfeed rifle then it should work fine. Some of the new Savage centerfeed rifles have different spacing so that is probably what you speak of.
If not, he can order stock:
#2997 Savage Short Action Varmint/Tactical with or without Accu-Trigger, Fits NEW STYLE “CENTERFEED” OR “INLINE FEED” Fits the short action "two digit models" only (such as Model 10, 10GY, 11F, 12, 16 etc.) with heavy contour barrel and blind top loading internal magazine, with action screws measuring 4.389"center to center only.
So it would be either #2997 or #2999, also depending if he has a short action or long action.