Home Forums Hunting & Shooting Hunting Rifles Range lesson from today - Magnetospeed.

I took advantage of a 36* morning with calm winds to hit the range. I tested a Kimber Montana and Fieldcraft in .270 Win. using 140 gr Acc's and 150 gr Partitions using H4831SC. After confirming zero at 100 I moved on to 200 yards. Both rifles did very well with both bullets. The Kimber favored the NP's and the Fieldcraft, the Acc's. Everything hovered around MOA.
After three-shot groups, I assembled the Magnetospeed on the Kimber. Immediately the groups opened to 4 and 5 inches with both bullets. With the FC, the groups opened to 5-6 inches at 200 yards.
I recorded the data, which was valuable and took off the device. Upon re-testing, the groups settled back down to pre-Magnetospeed results.
While the device is efficient and simple to use, there can be no doubt that it affects the poi's. Intuitively, the results aren't surprising, but they are documented enough for me to get the velocity data, but take it off to get valid point of impact results.

Have heard they can cause point of impact change and groups to open. I do not have one although I have considered one but have kept my old standard chrono. Maybe a Labradar would be better?

And that's why I can not stand them. I love my labradar. I like to search for velocity and accuracy at the same time when working up a load.

Yep good for testing velocity and that's it.

The Magnetospeed is very convenient to use and does not affect groups one bit when I go out in the garage and fire a few rounds into a five gallon bucket of sand.

The ProChrono won't work in the FL lighting and the Labradar would not work in this scenario, but I will get one eventually.

Magnetospeed is great for getting velocity. Nothing else. I have a bullet trap under my house where neither an optical system or Labradar would work but with the magnetospeed I can at least work up to find pressure without going to the range.

Yep, it’s another tool for the toolbox, and it has its place. It works great for a quick and easy way to get velocities in poor lighting conditions.

If someone was a bit creative, they could easily build a support of some type to have it free from the gun barrel

Yeah... no secrets here....

Is still my go to chrono for ease of set up, but my load work up is different and seldom, if ever, involves shooting paper groups.

They do. There is several attachments made to lock into an ARCA or Atlas rail. Granted you won’t find an ARCA rail on most hunting rigs, but the Atlas rail is a pretty common bipod attachment point.

Was referring more to a bench mount ahead of the gun rest. Takes portable out of the equation but wouldn't affect accuracy

Paging Dirtfarmer... He has one on a rifle rest that he places in front of the rifle.

I've been assured by those who have forgotten far more than I can ever hope to know that a Magnetospeed has no impact whatsoever on group size. You could not possibly have seen this happen, bigwhoop.

Dirtfarmer and Reloader28 have their Magnetospeeds mounted on stands just in front of the barrel so no effect on POI. Stands to reason thinner barrel profiles would be more affected when mounted on the barrel. Need enough shooting bench length to accommodate an off-barrel mount though.

Pics and discussion of their setups in the linked threads below.

Magneto speed questions

Magnetospeed chrongraph question

Confirming that the Magnetospeed affected the barrel harmonics certainly confirmed what we all suspected. But it still allows us to perform a valuable service - to grab some velocities as part of important data added to the logbook.

For the range the Labradar is it. Period. BTDT

Remind me to borrow your Labradar for testing velocity on some handloads I just worked up.

That has potential!

I suspect that it depends on the rifle and rest whether or not Magnetospeed chronographs effect group size or POI. I have been using the setup since they first appeared, and soon retired the Oehler 35P. While the Oehler unit was accurate, setting up all those tripods, screens and getting everything aligned and wired was too time consuming and laborious. Most of my test rifles are heavy barreled varmint models, using custom made barrels, laminated pillar bedded or chassis stocks, fired from a mechanical rest or Harris Bipod. and show undetectable changes in group size or POI. For me the Magnetospeed works well.