From my own experience, I'd say "maybe". Some of the older guns just flat-out don't work right on HPA. What kind of baffles me is that some of the same model DO work fine for other people. As an example, I've got an SL-68II, circa 1992, that refuses to get above 160fps on HPA. Some other people have said they've run similar vintage SL's on HPA with no problems at all.
I'd think your Sniper II should be fine, though, since that system is still used out and about in today's pumps. The F-1 might be hit-or-miss.