Magnetospeed problems?

[buckeyesguy5]

So I was shooting a known load today which is in the single digit sds and an avg velocity that always hovers in the same range. Today velocity was up 30-40 fps and sds were in the teens. Nothing has changed at all, so I'm wondering if there could be a prob with my magnetospeed v3. Anyone else have anything similar happen? Also the bayonet had a pretty good layer of carbon on it, could that be the prob? Thanks

 

[lash]

When you say that nothing at all has changed, does that mean the same lot of powder, the same primers and the same cases, processed in exactly the same way as before?

 

[buckeyesguy5]

When you say that nothing at all has changed, does that mean the same lot of powder, the same primers and the same cases, processed in exactly the same way as before?

Same lot of powder, same bullets, same box of primers and I had processed about 500 brass all the same way over about a weeks time early this winter. I had data from 68 degree weather at 2859, it was 62 today and I was getting 2890-2915ish.

 

[Kadams1563]

How many rounds on the gun between your test?


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[buckeyesguy5]

There were 0 rounds fired between the two instances, one outting to the next and the rifle was not cleaned.

 

[kabarNC]

Had that happen one time with a known load also, Prime 6.5 Creedmoor out of a Tikka CTR. The only thing I could figure out is the bayonet was not perfectly straight on both axis, it was pointing up and port, if that makes any sense. Fixed that, and never had any problems with it on any other platform either..

 

[LawnMM]

How many rounds on the barrel, total?

 

[Denny440]

I had the same thing happen. About a week later I went out to try it again and it wouldn't read at all. I went back to my $100 chrony.

 

[supercorndogs]

How many rounds and different days did you shoot to get your average? More rounds equals better data.

Check your air gap between your bullet and bayonet. If you get towards the edge of too wide it can do some weird things, but I have only seen this show up in 100fps swings.

One more thing could be the amount of time the rounds were loaded. The dissimilar metals in the case and the jacket can cause galvanic corrosion, that will stick the two together.

 

[buckeyesguy5]

The barrel has ~750 rds on it. The previous data was about 140 rds over 4 different days. I had the bayonet spacing set with the included rod each time. Maybe it was all a fluke but I'm really hoping it's not an issue with the barrel.

 

[supercorndogs]

Are you sure you are in the node? What bullet, powder, and case is it?

 

[buckeyesguy5]

I had sds of 6-9 from 42.4-42.6 and 10 at 42.7 with no pressure signs so I settled at 42.5 all of which were 1/2" or less 10 shot groups at 100. Berger 130 vld targets, imr 4451, fed 210m and Hornady cases.

 

[santee116]

May sound like a dumb question, but have you changed the 9-volt battery lately? Mine was acting up (odd velocity readings and sometimes no readings), changed the battery and its GTG now.

 

[Fred @ Bison Tactical]

I switched out to the CR123's since they last WAY longer in the V3. Also, I would suggest giving Ryan at call at MagnetoSpeed - he is a great resource and if anyone has heard of the issue he would have . I would however clean off the carbon on the bayonet and try again w/o the carbon.

 

[LSUbeatUby40]

I switched out to the CR123's since they last WAY longer in the V3. Also, I would suggest giving Ryan at call at MagnetoSpeed - he is a great resource and if anyone has heard of the issue he would have . I would however clean off the carbon on the bayonet and try again w/o the carbon.

How does your MSv3 work longer on 6vs of batteries vs a 9v battery? Just curious..

 

[Fred @ Bison Tactical]

How does your MSv3 work longer on 6vs of batteries vs a 9v battery? Just curious..

The V3 display unit will take both a Alkaline 9V rectangular battery or 2 CR123 batteries. The standard 9 Volt rectangular battery that comes with the unit doesn't last nearly as long as the CR123 lithium batteries. Also generally speaking Alkaline batteries tend to leak where Lithium batteries tend not to leak. For these reasons, I recommend switching out to the 2 CR123 batteries. In fact, on page 9 of the manual MagnetoSpeed says "CR123's provide much longer run time and at low temperature offer substantially better performance". Page 9 has a lot of information about battery choice, and most of it points towards using the CR123's over the Alkeline 9volt battery.

Specifically answering your question, the manual states "The system will operate normally as long as the battery voltage is over about 3.4 volts" - so I guess the extra voltage provided by the 9V battery just doesn't do anything, and 6V is plenty.

The manual gives some run times to illustrate why I switched:

@ 77 degrees F 2x CR123's get around 58 hours of run time
@ 77 degrees F 1 9V Alkaline get around 18 hours of run time

 

[Blowby]

 

[onlyhedge]

I have used my Chrono for over a year every weekend and now I've been through just two 9V batteries so not bad.

 

[Drew9299]

Check your batteries. Low battery could cause problems just like a powder scale

 

[cruze5]

this explains the extremely low velocity readings i was getting with my new Sako yesterday. so glad i found this thread. thank you all for the good information

 

[jab00]

What are you guys using to safely remove the carbon from the bayonet? Mine is starting to get a bit dirty

 

[rustyinbend]

I like my Magnetspeed V3 ... worked fine for me for a long time. That said ... I LOVE my Labradar ... especially with the JKL Recoil Trigger. So nice to be able to swap guns without all the gyrations required to remove and remount the Magnetospeed.

 

[dnchrist]

What are you guys using to safely remove the carbon from the bayonet? Mine is starting to get a bit dirty

Wiping with Simple Green, then water should work, but I haven't tried it. I use it for 5.7X28 cases in an ultrasonic cleaner and it works very well on them.