300 Blackout/Ruger American Ranch/Magnetospeed

[N21911S]

So I'm out at the range yesterday happily shooting the Blackout Ruger with Lee 312-155-2R boolits cast from Lyman #2 and sized .310. I've put a lot of these downrange looking for the magic combination for cast boolit steel silhouette competition. So far the best seems to be A1680 with a COAL of 2.1". It averages .8" average radius MOA. Thinking this might be the one, I strapped the Magnetospeed on and found an average velocity of 1840 fps with a disappointing sd of 25. BUT, it put 8 rounds into an average radius of .325". That's less than 1/2 of previous results. I had read that strapping a Magnetospeed on destroyed groups..........in this example that was not the case. I will be looking to this. Maybe the Limbsaver Barrel Dampener?

[RED333]

I have heard this works both ways, barrel whip makes my head hurt trying to think about it.

[N21911S]

Extreme spread was 77 fps. And yes the Magnetospeed Sportster works really good, never missed a shot. I like the ability to email home the results. What do you mean about "2 peaks"?

[Bjornb]

Been using the MagnetoSpeed for cast shooting in my XCB rifles for a year now. No problems or issues, have shot at speeds over 3300 fps, have several thousand rounds over the sensors with no visible wear or damage.

[wordsmith]

Been using the MagnetoSpeed for cast shooting in my XCB rifles for a year now. No problems or issues, have shot at speeds over 3300 fps, have several thousand rounds over the sensors with no visible wear or damage.

Second that. I've been using the Magnetospeed since they came out, owning all three generations. V3 works really well with cast boolits without a lot of settings tweaking. The key I've found is to make sure to optimize (minimize) the clear vertical distance between the bore line and the bayonet unit for reliable pick up of cast boolits. 1/4" or less is best, which takes some practice to get right.

[N21911S]

I have no experience with PB boolits and the Sportster, having only used GC. And have never messed with changing the sensitivity, it just works. Which is really good because I got tired of messing with the Ohler 33.

[wordsmith]

Does the sportster do plain base or is it seeing the GC? V3 has extra sensitivity settings, sportster only has 3. Lead has some different eddy current characteristics.

I haven't used the sporter at all, so I can't say. I've successfully picked up plain base with the V3 on the more sensitive setting 100% of the time at subsonic velocities, when I mind the vertical clearance. The same is true for picking up .25 pellets out of my Marauder.

I haven't tried it on "normal" settings.

[Blammer]

If I had the "magneto speed" I'd develop a group and load then put the device on to record velocity and forget about the groups it shot. I'd only use it for velocity not accuracy recordings.