I have one of these,it does around 2.3 fpe on 1 pump and 3.6 fpe on 2.3 pumps makes no difference you can here the valve dumping the air.
When being pumped I noticed that air is coming out of the tiny inlet hole at the front of the air cylinder,this doesn't seem right to me.I have had a look at the seals in the pump rod and they seem ok.It seems to blow off air on 1,2 or 3 pumps no matter if pumped fast or slow.I have lubed it with pelgun oil with no discernible difference.I have read these do around 3 fpe on 1 pump,around 5 fpe on 2 and 5.5 fpe or so on 3 so I'm at a bit of a loss with what to do.
I don't really want to strip it right down as I can make do with it as it is,just wondering if there is something amiss.