Magnetospeed to the rescue - MagnetoSpeed V3 Ballistic Chronograph Kit with Hard Case

So, word of advise do not try to buy one of these on ebay. The bayo should be flat and clean, not like a bullet augered a little groove on the top of the bayo surface. It is also surprisingly hard to find a picture or video showing the top of the byo. Aside from that this is beautiful! I sat, read the instructions, played with different spacers to get it exact. I may be a little more paranoid given my previous experience with the ebay one and I do not want to ruin the bayo, so I might be more cautious than most setting this up. I figured getting it mounted at home saves valuable range time, which I highly recommend. There's 2 sensors in the bayo, you can feel when I used the micrometer in the verification step with a cleaning rod sticking out of the muzzle measuring the gap between the rod and top of the bayo. The distance has to be 1/16" of each other, and you'll feel the magnetic pull of where the sensors are when you measure. I got lucky and both the rifles I tend to use for this are the same stack of spacers. The strap is a little tricky at first, but it could be me over thinking it some since it is getting strapped to the barrel. I recommend backing the securing knob out as much as possible with maybe just a few threads engaged, tighten the slack out of the strap, then start tightening the knob. It is in the instructions, but maybe tighten helps the next person a little easier. I would think to make it easier if you have different barrel dimensions and need different spacers, either writing the different stack of spacers down or get another set of spacers. There's plenty of room in the hard case to have more cutouts in the foam and may make life easier. I'm not super techy, so it'll be interesting figuring out the data side of it after shooting, but overall if you can sit with it without kids needing something every 30 seconds the set-up is pretty good, get the strap right and tight, get the measurements right then all it should need at the range is put it on and hook it up and go. From what I can tell magnetospeed is built really well. The price beat just about everyone. Just follow the directions and it'll make life easy.