Does a MagnetoSpeed Significantly Affect the Precision of a Rifle? – Sin City Precision
As previously published by Sin City Precision on 8/14/16.
As I have mentioned before I enjoy shooting the breeze about shooting especially while enjoying a few adult beverages. One reason why I enjoy talking about these things is that I really enjoy the activity. I am not referring to just the “trigger pulling” portion as I get great satisfaction in the aspects leading up to being able to pull the trigger and also the analysis done after the last trigger press has happened. Normally during these conversations something comes up where there is a difference of opinion. Being who I am there is a strong desire to have some type of quantitative evidence, or as some like to call it “hard data” to support a claim. In short, a subjective opinion with no data at all (c’mon gimme something tangible) makes me want to go hide in a cave in the fetal position and wait for humanity to fall apart. One of the discussion topics that has come up a few times is how a MagnetoSpeed affects the results and effectiveness when attempting to do load development. It has also been described that the MagnetoSpeed induces “flyers” when checking for precision of a load.
In a recent test I was checking on precision of charge weight and measurable performance advantage. During that charge weight test I was able to do some checks on performance with and without the MagnetoSpeed hooked up in the same session. In the effort of full disclosure in the past article I did have some rounds that exhibited loose primer pockets. Due to the nature of the tests and how shots were logged (namely I did not map individual shots in order) so I just have to take the data I have and go from there. All I can say is that the shots that were omitted due to primer pockets did not show any blatant “flyers” on those shot strings.
Pretty much anyone who has shot a suppressor will attest that the suppressor does in fact alter the point of impact on a rifle. Certainly in theory there is some contribution to a change of the Point of Impact (POI) by the bayonet of a Magnetospeed simply due to the added weight, but how much does it really play a role? Does this lightweight device result in a noticeable change in the Point of Impact (POI) by an average skill shooter? The other item is group size. Is it possible to do load testing while having the bayonet on to test speed as well as group size? Ideally I would burn through the ladder of charge weights with and without the chrono but even I didn’t want to blow through that much of the barrel. I am not even going to try to get into the idea of barrel harmonics and using speed values alone without even looking at the target to attempt to pick the best load for a barrel (That is a neat idea for another article and might be a good use for a spare 308 barrel I have sitting around now that I am typing this).
How this was done:
For each particular load, 5 rounds fired with the MagnetoSpeed attached, and data being taken with using both the MagnetoSpeed and the LabRadar. Allow for a cooldown after each 5 round string. The same test will be done without the MagnetoSpeed attached and data will still be recorded using the LabRadar.
The test rig is a Remington 700 sitting on an AICS, a Bartlein #13 barrel 26” chambered in 6.5 Creedmoor with a ThunderBeast 30P-1 can, a Timney 510 trigger, and until my other scope is in stock (c’mon Vortex where is my AMG) a Vortex Razor Gen2.