Regarding the magneto speed, when I use my chrono I'm load testing or ladder testing. Last thing I want on my gun during this stage is weight on my barrel. If I used my chrono just to review known loads then I would have a different opinion.
That is my reason I would never consider one....you asked Same concern I had prior to purchase. Have only used the magneto speed w/ 2 rifles so far. One w/ muzzle brake one w/o. My POI changed slightly but group size hasn't been effected so far. I really like being able to change to different elevations or hold on anything on the range w/o need to adjust screens. Don't have to wait for, or call, cease fires to adj. screens. I can shoot in the dark & still get accurate readings. No concerns about varying cloud cover. If it rains, no need to worry about electronics getting wet (w/ covered firing line) At my range I have to tote gear 100+ yds to firing line. The whole kit fits the pocket of my BDU's. Yes, its a new technology. But so far appears to be a huge step forward. The BBL's I've used have been varmint wgt or heavier, 26".
That is my reason I would never consider one....you asked Same concern I had prior to purchase. Have only used the magneto speed w/ 2 rifles so far. One w/ muzzle brake one w/o. My POI changed slightly but group size hasn't been effected so far. I really like being able to change to different elevations or hold on anything on the range w/o need to adjust screens. Don't have to wait for, or call, cease fires to adj. screens. I can shoot in the dark & still get accurate readings. No concerns about varying cloud cover. If it rains, no need to worry about electronics getting wet (w/ covered firing line) At my range I have to tote gear 100+ yds to firing line. The whole kit fits the pocket of my BDU's. Yes, its a new technology. But so far appears to be a huge step forward. The BBL's I've used have been varmint wgt or heavier, 26".