Walther OSP question

[BlackGrouper]

Have a 1970 year OSP, want to use it for basement plinking but .22 short match ammo is no longer available, have CCI 29gn 1080fps which is much hotter than these pistols were set up for. They used 27-29gn at something like 700-800fps.

Im wanting to see if replacing the recoil spring with a stiffer one would work to tune the slide energy for this ammo.
I found an old post online where someone with a lot of knowledge on these older Olympic pistols said it was OK to use the hotter CCI in these pistols but I still want to tune it anyhow.

Anyone have any experience with these pistols?

Thanks, Ron

 

[BlackGrouper]

Update:
Shot 300rds of CCI CB short through the pistol, cycles perfect and is accurate enough for shooting 30ft in my basement. Seems like the new batches of CBs are alot more consistant than they used to be.
No misfires or weak rounds. Shot a 1/2" 10rd group (using both hands
Thought I would post this in case anyone who has one of these old Olympic guns wants to use one to practice bullseye at home as match ammo is no longer made for these.