All the guns that I have except one has the DonnyFL Sumo on them. That one exception is the Edgun R5M Long. I can't get the FX Radar to work on it to save my life. Probably because the air tube comes almost to the end of the shroud … and who knows, maybe that little electronic gage in the air tube throws the radar out of wack. Even tried placing the radar under the front end of the stock … wouldn't even register!
Just from my own observations and I am by no means an expert, you need a shroud or LDC that sticks out in front of the air tube by at least 3 inches to place the radar under. It needs a distance of 1/2" to 1" clearance directly underneath the moderator. It MUST be lined up very closely with your barrel and your target so it can catch and record the pellet in flight. For those of us who usually shoot off an old wobbly table … it is easier said than done … but it can work. Just depends upon how much frustration you are willing to put up with.
When I was able to get readings from the Edgun they were anywhere from 850 to 920 with the JSB 33.95 MK2. The other guns I have seem to work pretty good, just place the radar headed the right way, about half way down the Sumo and an inch below it. I shot my Vulcan 2 Tactic yesterday and it was running 900 to 909 … moved the radar to shoot over it with the Cricket and it was going 908 to 895 … put the Vulcan Tactic back on it and this morning and it was shooting very close to the same range it was the day before ... 898 to 910 and the Cricket was going 893 to 910. I don't know, time of day, humidity or thickness of the air.
I was trying to get the Edgun to shoot in the range of about 850 fps with the MK2s but every time I would move the HST the radar (when it would give a reading) would jump sometimes 40 to 50 fps with only a 1 click turn of the HST.
I haven't tried the Wildcat or the Impact yet, but would expect the results to be similar to the Tactic and the Cricket … they are all in .25 cal … have no idea whether a .22 cal would work as well.
One thing is for sure, the placement of the radar is everything
As of this time, I am not sure if I will keep it or not … glad I still have my old Pro Chrono
John