$400 +Shipping
Bought I bought the MagnetoSpeed 4 or 5 years ago. Used it as a backup to my Lab Radar when doing testing. I bought the Gray Ops Bayonet Mount 2 years ago after trying some other mounting methods. The Gray Ops is by far the best (non barrel attached) mounting method there is. I've used it on sporterweight skinny and short barrels and 31" 1.25" straight taper barrels and have had no issues.
https://magnetospeed.com/v3-ballistic-chronograph
($450 New)
https://grayopscnc.com/products/magento-speed-v3-mount
($320 New)