Magnetospeed barrel mount chrono's?

[Inline6]

Range report for MagnetoSpeed vs LabRadar:

Working on loads for my 280 AI this weekend, my buddy brought his LabRadar and I brought my MagnetoSpeed.

LabRadar reported higher MV on every shot, anywhere from about 20 - 40 fps faster than the MagnetoSpeed showed. I'd guess that the LabRadar is probably more accurate, but I believe we're splitting frog hairs 4 ways in this comparison.

There was enough consistency in the delta between what they were both reporting that they both identified pressure nodes in the exact same two places

MagnetoSpeed showed
2637
2637
2636
2627
2639

On that same part of the string, LabRadar showed
2663
2665
2657
2648
2667

I don't find issues with the MS affecting accuracy much. That's 2 groups of 4 all touching, and a 9th right in the middle that's pretty close.

View attachment 519845

I have ran this test on mine couple dozen times. Never had more then 2fps difference between my two.

The only factors I know that would play hand in this. 1 the MS is not set to the correct distance from bore. 2 the LR is not set in the correct distance for the muzzle causing it to trigger at the wrong time.

My sample size is small, two different sets of units mine and my buddies. We both wanted to see what if any difference.

 

[sgt_zim]

I have ran this test on mine couple dozen times. Never had more then 2fps difference between my two.

The only factors I know that would play hand in this. 1 the MS is not set to the correct distance from bore. 2 the LR is not set in the correct distance for the muzzle causing it to trigger at the wrong time.

My sample size is small, two different sets of units mine and my buddies. We both wanted to see what if any difference.

We of course had a small sample size as well. I'm not overly concerned about the difference we saw between them. Both are accurate enough for the distances we're willing to hunt - for our 280 AIs, that's out to 500-600 yards. If we were match or f-class shooters, well, a little more diligence in those details would be warranted.

The issue with the MS placement on my rifle is barrel taper, which seems to be a little sharper at the end of the barrel. The MS walks forward by every 3rd shot. By placing it a little further back, it stays nice and tight, and there is still probably 2-3" between the front of the scabbard and the muzzle of the rifle. Either way you slice it, I'm getting 7mm RM velocity with the 160 gr SAF with no signs of pressure. Primers and brass are the same on the low end as they are on the high end.

We did have the LR a little too far back for the first couple shots, it was showing MV at around 2050 fps when the MS was showing 2600+. But my buddy made some adjustments and it started showing MV close enough to the MS that we didn't think too much of it.

 

[JGRaider]

I use my MS quite often, and trust the readouts it's giving me. Never used the LR.

 

[Hogpatrol]

IIRC, the MS directions call for the aft part of the blade to be one inch from the muzzle. Agree the clamping setup leaves a lot to be desired. There are aftermarket units that attach to the forearm stop on front rests, negate that problem.

 

[nomspc]

I tried the Magnetospeed and found the constant repositioning inconvenient. LabRadar is way better in all respects except price.

 

[Bob Nelson 35Whelen]

We of course had a small sample size as well. I'm not overly concerned about the difference we saw between them. Both are accurate enough for the distances we're willing to hunt - for our 280 AIs, that's out to 500-600 yards. If we were match or f-class shooters, well, a little more diligence in those details would be warranted.

The issue with the MS placement on my rifle is barrel taper, which seems to be a little sharper at the end of the barrel. The MS walks forward by every 3rd shot. By placing it a little further back, it stays nice and tight, and there is still probably 2-3" between the front of the scabbard and the muzzle of the rifle. Either way you slice it, I'm getting 7mm RM velocity with the 160 gr SAF with no signs of pressure. Primers and brass are the same on the low end as they are on the high end.

We did have the LR a little too far back for the first couple shots, it was showing MV at around 2050 fps when the MS was showing 2600+. But my buddy made some adjustments and it started showing MV close enough to the MS that we didn't think too much of it.

@sgt_zim
I think I will stick with my old chrony chronograph. A bit slow to set up. I check it after set up with my 22lr with ammo of a known velocity to make sure it's fine.
Accurate enough for me.
Be interesting to calibrate the MS and lab radar with a 22lr out of the same rifle to see how much the difference actually is.
Bob

 

[sgt_zim]

@sgt_zim
I think I will stick with my old chrony chronograph. A bit slow to set up. I check it after set up with my 22lr with ammo of a known velocity to make sure it's fine.
Accurate enough for me.
Be interesting to calibrate the MS and lab radar with a 22lr out of the same rifle to see how much the difference actually is.
Bob

I really only have 1 place to set up for LD, and that's at a public range. So I have to get there at least 30 minutes before it opens so I don't have to worry about a hot range.

I can do (and have done) it at my place in Louisiana, but that's a 5 hour drive 1 way. The MS is just much easier for me to set up, and it's accurate enough for my purposes to work with.

They say there are 2 kinds of chronos - those that have been shot, and those that are going to be shot. My first one was a simple Competition Electronics, which I had for about 5 or 6 years before I finally put a bullet in it.

 

[Inline6]

We of course had a small sample size as well. I'm not overly concerned about the difference we saw between them. Both are accurate enough for the distances we're willing to hunt - for our 280 AIs, that's out to 500-600 yards. If we were match or f-class shooters, well, a little more diligence in those details would be warranted.

The issue with the MS placement on my rifle is barrel taper, which seems to be a little sharper at the end of the barrel. The MS walks forward by every 3rd shot. By placing it a little further back, it stays nice and tight, and there is still probably 2-3" between the front of the scabbard and the muzzle of the rifle. Either way you slice it, I'm getting 7mm RM velocity with the 160 gr SAF with no signs of pressure. Primers and brass are the same on the low end as they are on the high end.

We did have the LR a little too far back for the first couple shots, it was showing MV at around 2050 fps when the MS was showing 2600+. But my buddy made some adjustments and it started showing MV close enough to the MS that we didn't think too much of it.

Please don't take this the wrong way. F class is one of the last disciplines that needs exact speeds. They get sighters, in the field we do not have that luxury. We have to make our first shot count. If you are using a program to calculate your drop/wind drift. It only works as good as the information you feed it. On the MS I have taken some of the rubber spacers and wedged it under the part closest to the muzzle to offset the barrel taper. It works for what it is. Smaller barrels are just a little more difficult to setup, it is worth making sure you get the best data you can.

 

[sgt_zim]

Please don't take this the wrong way. F class is one of the last disciplines that needs exact speeds. They get sighters, in the field we do not have that luxury. We have to make our first shot count. If you are using a program to calculate your drop/wind drift. It only works as good as the information you feed it. On the MS I have taken some of the rubber spacers and wedged it under the part closest to the muzzle to offset the barrel taper. It works for what it is. Smaller barrels are just a little more difficult to setup, it is worth making sure you get the best data you can.

No offense taken.

Hornady's ballistic calculator is a nice tool to get me close (based on chrony info), but only slinging lead downrange tells the real story.

 

[Inline6]

No offense taken.

Hornady's ballistic calculator is a nice tool to get me close (based on chrony info), but only slinging lead downrange tells the real story.

Using AB I have made first round impacts at 1 mile on small plates 1/2 MOA. Everything plays a small factor, enough small factor add up to a miss.

Agree testing is confirming that everything is working. Lots of things play out when you change elevation, temperature and well you name it.

Heck I use a program that helps me find a load for my rifle. It is scary how accurate it is. We are lucky to have the technology that we do. It definitely makes us better shooters.

 

[meigsbucks]

There was a guy using a MS at the range last year. He put strips of toolbox liner under the strap. He said it significantly cut down on the unit sliding.

 

[hatfield]

I used an Oehler for years but they are a pain to set up and are picky about sun and shade.
I have a Magnetospeed and find it to be very accurate if the right spacers are installed.
You lose the ability to work up loads with it on the gun, because it affects barrel harmonics.
I generally work up my loads for best group, and then install it to get velocity to enter in my Kestral.
Lab radar or andiscan is a much better choice if you have deep pockets, but if you just need to get a speed reading, its the best bang for the buck.

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