velocity seems a bit high

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gunlaker
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velocity seems a bit high

Post by gunlaker » Wed May 15, 2019 6:43 pm

What do you think of this muzzle velocity? Taken by my Magnetospeed. The Swiss number seems a little high to me.

.45-70
532gr Money bullet
65gr Swiss 1.5
14 shot average vel 1245 fps.

by comparison here is a load in the same rifle, but with plain Goex FFFg also taken today right after checking the Swiss numbers.
538gr PJ Creedmoor
65gr Goex FFFg
8 shot average vel 1190 fps.

I expected the Swiss 1.5 load to read about 50 fps slower so I wonder if the Magnetospeed is a bit wonky. It seems to shoot pretty well on the turkey line, and reasonably well at the rams, although with a bit more vertical than I'd like.

Chris.

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art ruggiero
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Re: velocity seems a bit high

Post by art ruggiero » Thu May 16, 2019 9:08 am

the swiss number is to high my 45/70 load with 70 gr swiss 1.5 and 540 gr. creedmoor runs 1220 art

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Lumpy Grits
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Re: velocity seems a bit high

Post by Lumpy Grits » Thu May 16, 2019 10:44 am

What's your BBL length?
Did you 'tune' the sensor as per instructions?
FWIW: I get pretty much the same FPS with Old 'E' 2 F.
Gary
"Hav'n you along, is like loose'n two good men"

gunlaker
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Re: velocity seems a bit high

Post by gunlaker » Thu May 16, 2019 2:24 pm

Thanks Art, that's what I thought.

Gary mine has no facility for tuning the sensors and definitely nothing in the instructions about it. Mine is a V.3 what version is yours? I haven't ever updated the software on it, so maybe the newer ones have that feature?

The barrel length is only 30".

I could run some .22's over it, but I don't know what sort of velocities to expect with a 28" barrel vs. velocity data printed on the box.

Chris.

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Lumpy Grits
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Re: velocity seems a bit high

Post by Lumpy Grits » Thu May 16, 2019 4:00 pm

I don't have one-I related what a friend did when he had the same issue.
Also-are you using a 'full' battery each session?
G.
"Hav'n you along, is like loose'n two good men"

gunlaker
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Re: velocity seems a bit high

Post by gunlaker » Thu May 16, 2019 4:22 pm

Yeah batteries have lots of juice :-).

Chris.

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Lumpy Grits
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Re: velocity seems a bit high

Post by Lumpy Grits » Thu May 16, 2019 6:29 pm

My PACT crono gets fresh batteries for each session.
Chris-Does yours use rechargeable or throw away type?
G.
"Hav'n you along, is like loose'n two good men"

gunlaker
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Re: velocity seems a bit high

Post by gunlaker » Fri May 17, 2019 6:55 am

Gary mine uses two of the CR123 batteries ( throw away ). It claims 50 hours of run time which is a pile. It also has a battery status in the menu system somewhere. They are definitely good. These days low if low batteries are causing a device to malfunction then it is just cheapness on the part of the manufacturer. It's super easy for any of these devices to include a low battery indicator on them.

Chris.

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Lumpy Grits
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Re: velocity seems a bit high

Post by Lumpy Grits » Fri May 17, 2019 9:50 am

Did not recall they used 123 batteries. Good long lasting batteries.
You can get a really good price on 123's from Sure-Fire.
My 20 yo PACT uses 1, 9volt.
G
"Hav'n you along, is like loose'n two good men"

gunlaker
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Re: velocity seems a bit high

Post by gunlaker » Tue May 21, 2019 11:27 am

Ok I believe I have an idea as to what it might be. I think all of the powder residue has sandblasted the heck out of my Magnetospeed :lol:

I have shot an awful lot of rounds over it so I can't really complain.

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Lumpy Grits
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Re: velocity seems a bit high

Post by Lumpy Grits » Tue May 21, 2019 12:26 pm

I would think either black or white powder would cut that. :?
G.
"Hav'n you along, is like loose'n two good men"

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