Magnetospeed / Barrel tuners

[Artiglio]

Good day,

 

From various posts, it appears that a general view is that a magnetospeed chrony added to a barrel only affects POI rather than barrel harmonics in general. Surely this flies in face of the idea of barrel tuners, which as I understand it tailor barrel harmonics to your ammunition by altering the mass on the end of the barrel.

I ask as I recently carried out a seating depth test on my WSM and was amazed when groups suddenly shrank from around 0.5moa to just over 0.25moa. But when I checked my figures at home realised that I'd also used my magnetospeed for the final 2 groups. Which were the best by far.

Easy enough to check next time out as to whether the load is as good without the chrony attached, however if the load performs best with the chrony fixed, maybe a barrel tuner is the next move.

 

cheers phil

[jcampbellsmith]

Good day,

 

From various posts, it appears that a general view is that a magnetospeed chrony added to a barrel only affects POI rather than barrel harmonics in general. Surely this flies in face of the idea of barrel tuners, which as I understand it tailor barrel harmonics to your ammunition by altering the mass on the end of the barrel.

I ask as I recently carried out a seating depth test on my WSM and was amazed when groups suddenly shrank from around 0.5moa to just over 0.25moa. But when I checked my figures at home realised that I'd also used my magnetospeed for the final 2 groups. Which were the best by far.

Easy enough to check next time out as to whether the load is as good without the chrony attached, however if the load performs best with the chrony fixed, maybe a barrel tuner is the next move.

 

cheers phil

 

Phil. Possibly, or you need to revisit your load development. I don't notice any change in POI when using the magnetospeed chrono, however I am mounting it on an AU-SL5 moderator.

https://dl.dropboxusercontent.com/u/12296998/Magnetospeed/GAT%20Rifles%20260%20Rem%20%2B%20MagnetoSpeed.jpg

I think research can only get you so far, then you need to test and retest your hypotheses.

I would be inclined to perform a test along the lines of:

 

3 shots chrono on

3 shots chrono off

3 shots chrono on

3 shots chrono off

 

using a fresh target for each group of three shots.

 

Regards

 

JCS

[Laurie]

It definitely affects group size, although the barrel weight / thickness / stiffness has a major influence on the degree of the change. On full scale heavy varmint / F-Class profiles there isn't a great deal of change, sometimes not enough to notice, but effects increase as barrel weight and stiffness decrease. I would not accept a test group size / shape on 32-inch Heavy Palma profile barrels and will always do final tuning for group with the Magnetospeed on. I've yet to use it on an ordinary sporting rifle with a light barrel, but I expect it to have a major effect in this instance.

 

A lot of the POI change is due to muzzle blast deflection rather than harmonics, so that with the Magnetospeed fitted at the 6 o'clock position where most people place it, it pushes POI up. However, the device can be fitted at any point of the circumference on plain barrels without sights, so users should be aware of this characteristic.