Looking for experience and advice with the S&T Winchester 1887

[Taylor7500]

In short I'm very interested in this gun, however I have some fps concerns. Most reviews I come across list its fps on one BB to be around 1.2-1.3J on green gas which won't fly for use in games (my local site chronos gas shotguns with one BB per shot to prevent issues with measurement). I don't know to what extent that's true, or whether there's some other factor like the version shipped to UK retailers having been adjusted, since every retailer quotes the fps at 1J exactly. Can anyone confirm whether it'll be above 1J on a single BB shot?

Similarly I've seen some people suggest using lower pressure gas like 134A to bring down the fps. Has anyone done this and if so did it bring hte fps to reliably at 1J or below?