I broke down and bought a Magneto Speed V3 a few weeks ago after getting frustrated with my Shooting Chrony. The Chrony accurate velocities when it would read, but I got sick of being at the mercy of the weather. Too much sun, not enough sun, shadows, rain, wind, I finally had enough. My biggest concern with the Magneto was the potential POI shift with it on and off. That's the only reason I waited so long to try it.
Since my original plans of taking the boat to Westport for some ling fishing didn't work out (everybody freaked out just because of a little wind and some small 8' swells
) I figured that it would be good shooting weather.
I drug out a couple different guns to test the POI shift with the Magneto on and off. The results were pretty encouraging. The average POI shift was about 1.5" with the group size staying pretty much the same. This was hard to really judge for the most part because we were testing a couple of different loads in most of the guns. The only one which showed a dramatic shift was my 7mm RUM. It shifted 4" and the groups doubled in size. The 260 Striker seemed to actually shoot a little better with the chrony strapped on!
The best result was from my 6mm BR. This picture is of a 10 shot group fired at 100 yards. That's 5 shots with the Magneto on and 5 shots with it off. The flyers to each side of the group were all me/bad wind calls. That little 90gr bullet is only moving at 2700 fps from the 19" barrel, so a 15 mph gust will really do a number on it!
I was worried about doing load developments with the Magneto strapped to the gun but now I really don't think I'd worry about it on a heavy (varmint profile) barrel. Next time I'll try and bring out a gun with a more conventional sporter profile barrel and see how that works.
Andrew
