Originally Posted by sjburgon
Hi, Havent really noticed any improvement or worsening of groups , but to be honest i am not the best shot in the world. I was told by harry that they did a number of bench tests which involved changing the port while the rifle stayed on the bench in position and that there was some improvement. If anyone else could shed a light on this it would be interesting to know.
I'm not familiar with the green port, but the silver port is 2.5mm, and the black port is 4.4mm.
There is also a gold port to convert the rifle to 7.5 Joules (not sure how big the hole is, but I guess it's about 1.5mm).
Are you sure the green port isn't a silver port with a green O-ring?
Anyway, the silver port gives about 60 shots (as Chris said), and the black gives about 110 shots.
On grouping, I haven't noticed any difference at all, and the shot to shot consistency is about the same (2-3fps with weighed pellets).
I find it strange that the testing was done from a bench rest, just by swapping the ports out, without also reducing the power (to under 12fpe). I'm assuming that Harry would have also adjusted the power as well as swapping the ports.
Just swapping the ports will make a significant difference to power output, and as the Steyr is more accurate in the mid 11's, then swapping the port to black without also adjusting the power to mid 11's would obviously affect the accuracy.
Hope this helps.