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None changed for me.
 

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Unless you plan on shooting in the field with the Magneto speed attached what difference does it make. Most people I know with Magneto speeds, that use them while working up a load, just shoot and evaluate the groups they get with the M/S attached and when done make the necessary adjustments in their zero with their sighter shots.

FWIW, the POI shift will be different on every barrel so as Rhyno430 said "Depends".
 

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Are these more accurate than conventional chronos or just more convenient?
I'm going to offer an opinion based on my previous experience with speed measuring equipment. When measuring speed between two points there are two key parameters. First and foremost, the "trigger signals" have to be exactly the same every time. When a bullet, for example, passes each sensor they have to trigger off the SAME point. If one triggers off the point and the second (stop) triggers off a point farther back, you already have a built in error.

Second, distance between sensors has an effect. The magneto speed has closely spaced sensors. Compare that with the "Gold Standard" of the chronograph world, the Oehler 35 that has several feet between sensors as well as a third sensor to validate the first set of readings (Much like one would use two stop watches to get a closer time reading in a race (or even the old fashioned speed "clocking" from the air by State Troopers).

The closer the sensors the faster the computer clock speed.


Now for the real question, is the Magneto Speed "Accurate Enough". Sure seems to be but if you want to get the most accurate, consider one of those 8' long Oehler's.

Yes, the Magneto Speed wins for convenience but I've never found it to be a hassle setting up my Pact. I just use it after all load development is done then I'll shoot a practice session over it, at least 25 rounds or more, so I have a good handle on the speed, ES/SD.
 

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I'm going to offer an opinion based on my previous experience with speed measuring equipment. When measuring speed between two points there are two key parameters. First and foremost, the "trigger signals" have to be exactly the same every time. When a bullet, for example, passes each sensor they have to trigger off the SAME point. If one triggers off the point and the second (stop) triggers off a point farther back, you already have a built in error.

Second, distance between sensors has an effect. The magneto speed has closely spaced sensors. Compare that with the "Gold Standard" of the chronograph world, the Oehler 35 that has several feet between sensors as well as a third sensor to validate the first set of readings (Much like one would use two stop watches to get a closer time reading in a race (or even the old fashioned speed "clocking" from the air by State Troopers).

The closer the sensors the faster the computer clock speed.


Now for the real question, is the Magneto Speed "Accurate Enough". Sure seems to be but if you want to get the most accurate, consider one of those 8' long Oehler's.

Yes, the Magneto Speed wins for convenience but I've never found it to be a hassle setting up my Pact. I just use it after all load development is done then I'll shoot a practice session over it, at least 25 rounds or more, so I have a good handle on the speed, ES/SD.
Thank you. That is very helpful, I'm just putting the finishing touches on collecting the gear I need for this "sport" (it's as bad as women or cars:). I've got a LRI barrel ready for my RPR and a Kahles 624 on the way (thanks Mike at CS Tactical!!!). I think I'll save the $400 and just buy ammo.
 

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Thank you. That is very helpful, I'm just putting the finishing touches on collecting the gear I need for this "sport" (it's as bad as women or cars. I've got a LRI barrel ready for my RPR and a Kahles 624 on the way (thanks Mike at CS Tactical!!!). I think I'll save the $400 and just buy ammo.
If you want a simple chrono that works good as long as you have steady lighting outdoors (sunshine, not thick clouds), get a Shooting Chrony for not much over $100. Just make sure to get one that has the readout back at the bench. For quick setup, and avoiding the common error of not allowing for scope height, get a chamber type laser bore sighter and use it to set the rig up. Where the dot shows on your hand is where the bullet will pass over each sensor. This unit will give you basic speed, ES, SD, Average speed, and more than accurate enough for ballistic's calcs. In the end you'll develop the DOPE for your rifle and ammo but the chrono will get you real close.
 

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If you want a simple chrono that works good as long as you have steady lighting outdoors (sunshine, not thick clouds), get a Shooting Chrony for not much over $100. Just make sure to get one that has the readout back at the bench. For quick setup, and avoiding the common error of not allowing for scope height, get a chamber type laser bore sighter and use it to set the rig up. Where the dot shows on your hand is where the bullet will pass over each sensor. This unit will give you basic speed, ES, SD, Average speed, and more than accurate enough for ballistic's calcs. In the end you'll develop the DOPE for your rifle and ammo but the chrono will get you real close.
I have to disagree with you on this one.

The Magnetospeed Sporter is $179 and as long as you don't have a suppressor or gigantic brake, it mount's easily to the firearm and unless you really mess up it's hard to shoot. The Shooting Chrony is $139 for an acceptable model and those of us that have used them know that set-up is not simple and shooting them is fairly easy if you are not paying attention. They do have their drawbacks but I prefer them to traditional chronographs for their ease of use and their accuracy.

OP, to your original question about the POI shift, I had a 2.5Mil shift toward the 2 o'clock and groups opened up from .3-.50MOA to 1.5-2MOA.

~Ben
 

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The Shooting Chrony is $139 for an acceptable model and those of us that have used them know that set-up is not simple and shooting them is fairly easy if you are not paying attention.
Around here there are numerous Shooting Chrony's available for ~$100, with the remote, bench top control. Some are new, on sale, and others are being sold by shooters that either don't use a chronograph anymore or make the jump to the more expensive Magnetospeed's.

As for setup, if one uses a chamber type laser bore sighter, sights the rifle on the target and secures with adjustable rest, on bipod, and rear sandbag, setup is about as long as it takes to put the tripod in place and line up the dot over the sensors. No need to run back and forth or have a helper guide you into position.

I don't have any issues with magnetospeed chrono's and for those that want them just remember that they too have their setup issues with strap,shim/spacers, alignment with bore, etc. Then there's the issue of suppressor or huge brake.

What's interesting is the number of chronographs in a market that was once limited to people who only hand deeper pockets than most. Now you can buy a "Fold -a - Box" Chrony off most bulletin boards for ~$50. I use one for "Downrange" speed measurements when I want to do my own BC Calc's.
 

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Buy a copy of: Modern Advancements In Long Range Shooting, Volume I by Bryan Litz.
Then read chapter 15, Measuring Muzzle Velocity.
Spoiler Alert: The top two choices are the Magneto Speed and the Oehler 35P with 4' spacing.

I own and operate both and Bryan is correct.

Anyone involved in the long range shooting business really needs to read everything Bryan Litz has written.
 
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