decision on chronograph

[MontanaRifleman]

Agree with BnG. My ProChrono and Shooting Chorny have given me big shifts in velocity with changing light conditions, not to mention spreads of 5 fps to 60 fps when set up back to back with the same load and light conditions. Anyone using these instruments to determine the consistency of their load is using unreliable data IME.

I haven't heard of anyone yet saying the MagnetoSpeed has significantly altered their groups. Some have said there may be a slight shift in POI, others say can't tell the difference. In any case, once you've fired a few rounds of a particular load and have an accurate MV to work with, you don't need it anymore.

 

[Damascus]

I've had a Chrony Gamma for about 10 years, and it would always record the MV on the display, but only send to the printer about 8 or 9 out of every 10 shots. It recently started giving me similar error messages - completely out of the blue. Chrony said to clean the sensors (which I already had). It's dead and I'm looking for another brand. :-O

I traced mine down to a broken wire (the flat ribbon wire on the inside that connects the 2 sensors... I took care never to pinch it when I closed the unit - but it still gets crammed in there if you leave the phone line cable inside...
Shooting Chrony needs to beef up this wire significantly if they want to compete with the other brands.... I love the folding, portable concept, but it really needs to be beefed up to withstand normal use.

As for the talking about "nodes".. for people who don't know what this means: When a bullet is fired down a barrel, it spins with an insane amount of speed and force, cause the barrel to actually "whip", image a sine wave (up and down like waves on an ocean) - then image this is in 3D, going up and down while also rotating in a circle.
Some barrels/twist rates will shoot wonderful groups when they are thrown at a "sweet spot" in velocity.. and groups suffer if you go over or under that sweet spot - this is the node concept.

The barrel "whipping" is why everyone wants a thicker, stiffer barrel - but engineers realized quick that YOU SIMPLY CANNOT eliminate the flex/whip - the key to accuracy is finding an accurate node/speed window that causes the barrel to flex/whip EXACTLY the same way, every time. You will also find that if you stick in the velocity sweet spot, nearly all bullets will shoot well.

And of course, you'll never identify that sweet spot without an accurate chronograph.

 

[MontanaRifleman]

And of course, you'll never identify that sweet spot without an accurate chronograph.

I wouldn't say that... An accurate chronograph can be a valuable tool, but it isn't required to find an accurate load. I have found a number of accurate loads with cheep chronos. I look at the groups. That's what counts.

 

[M1AShooter]

I traced mine down to a broken wire (the flat ribbon wire on the inside that connects the 2 sensors... I took care never to pinch it when I closed the unit - but it still gets crammed in there if you leave the phone line cable inside...
Shooting Chrony needs to beef up this wire significantly if they want to compete with the other brands.... I love the folding, portable concept, but it really needs to be beefed up to withstand normal use.

My wiring is a little chafed where it got pinched when the unit was folded, but it appears to be just the clear covering over the three wires. Unless there's something internal at one sensor or the other, but I get alternating error messages indicating both sensors. I think you're right; I think it's a wiring issue and I also think Chrony does need to address that in their design and construction.

 

[dmax1800]

Is a magnetospeed at Brownells, $300 with shipping and tax, really worth the money compared to a Prochrono at Midway for $140 with shipping??? Is the magnetospeed going to be a lot more accurate, consistent and reliable ???

I know it is not sensitive to light conditions at all, but is the magnetospeed really worth the extra money??? Thats what I'm wondering.

 

[MontanaRifleman]

Is a magnetospeed at Brownells, $300 with shipping and tax, really worth the money compared to a Prochrono at Midway for $140 with shipping??? Is the magnetospeed going to be a lot more accurate, consistent and reliable ???

I know it is not sensitive to light conditions at all, but is the magnetospeed really worth the extra money??? Thats what I'm wondering.

Yup, I own a ProChrono and overall it gives fairly good info but it will give a range of readings depending on light conditions on the same load.

Back in June, Broz sponsered a Long Range shoot in Townsend. We set up his Oehler, my SuperChrono and then 4 of us, Me, Broz, bigngreen and Barnesuser, each shot our rifles over them ranging from 223 to 338 LM with the Magnetospeed attached to the muzzles. The MagnetoSpeed agreed with the Oehler to within a couple of fps when corrected for distance to chrono. Shot to shot variance was very low and averages were extremely close between the 2. That made a believer out of me and my next chrono will be a MagnetoSpeed.

My ProChrono will be up for sale for a good price before long if you're interested

 

[dmax1800]

I took most everyones opinion and ordered a Magnetospeed V1 this morning. I hope it is as accurate and reliable as everyone says it is. It was also reassuring to talk to Magnetospeed and hear that when tested against an optical camera, their magnetospeed was 99.99% accurate.
Thanks to everyone who helped me make this decision.

 

[Damascus]

I wouldn't say that... An accurate chronograph can be a valuable tool, but it isn't required to find an accurate load. I have found a number of accurate loads with cheep chronos. I look at the groups. That's what counts.

Yes, I agree with you, however I feel that developing a load not knowing it's speed is potentially dangerous, or at least could be hard on your rifle.
Some rifles shows pressure signs very early, others won't show any signs till they're on the brink of catastrophic failure.

I once had a Winchester M70 Laredo (Winchester's version of Remington's Sendero) in .300 Win Mag. I started loading a long range whitetail load using 168 gr. Barnes T-TSX's and Retumbo... Very quickly found a load that I knew would/should be quite hot and it consistently printed .4 MOA groups.. I probably used this load for 2 seasons, firing probably 300 rounds of it, till" I chrono'ed it and found that it was shooting roughly 265 fps faster than all similar factory ammo - obviously overpressured, but showing no signs on fired cases.
On this flip side of this coin, I own 2 identical Remington 700 SPS's in .30-06, same barrel length/contour, etc... One of them can easily exceed Hornady's published max load (4350/165 SST) by almost 2 grains before I can find evidence like leaking primers (barely) and/or shiny case heads and flowed stamps... The other 700 - I can't even get to the max load before expanding pockets and case heads - as a matter of fact, it starts showing signs at 2 gr. over the starting load!
My point I suppose is that every chamber is different, either by dimensions or surface smoothness, tooling marks, etc., regardless of even being the same make and model - as the 700 SPS that shows signs early must have a much tighter chamber, or extremely excessive headspace, or a number of other possibilities... I've not taken them apart to compare to investigate the cause of this, since these are both "rainy day" rifles that I leave out at locations where they may be useful.

I just think that a chronograph is as important reloading tool as the press or powder scale Again, everyone's needs are different, and to someone just loading standard pressure, factory-dupe'd published loads that aren't going to be used for precision purposes has less of a need for a chrono than I do.. meaning that I'm one of those guys that has to do every single possible step - turning necks, sorting weight classes, uniforming pockets and deburring flash holes -- you get the idea, I'll not go on... All I can say is that I'm the guy most others hate to load with, since my friends can usually load 4 or 5 rounds to my 1 LOL... However, once the targets starts to get really small, all my perfectionist/OCD tendancies begin to pay off

 

[clemens]

If the magneto chrono did change POI on paper just in the development stage and your group size is where you wanted it, would it or would it not shift (poi)back to original POI or zero and if not could it be fine tuned during the drop chart phase?

 

[Greyfox]

If the magneto chrono did change POI on paper just in the development stage and your group size is where you wanted it, would it or would it not shift (poi)back to original POI or zero and if not could it be fine tuned during the drop chart phase?

I have used the MS with a few rifles. On two, there was no change in POI. One did change POI, but it returned to the original POI when the Magnetospeed was removed. Heavier barreled rifles appear less, or not effected at all.

 

[birddog67]

Used to have a chrono beta ,Ickes up an magnito speed v2 I will never look back now . Easy set up and volicity right on. gun)

 

[300stw]

Yup, I own a ProChrono and overall it gives fairly good info but it will give a range of readings depending on light conditions on the same load.

Back in June, Broz sponsered a Long Range shoot in Townsend. We set up his Oehler, my SuperChrono and then 4 of us, Me, Broz, bigngreen and Barnesuser, each shot our rifles over them ranging from 223 to 338 LM with the Magnetospeed attached to the muzzles. The MagnetoSpeed agreed with the Oehler to within a couple of fps when corrected for distance to chrono. Shot to shot variance was very low and averages were extremely close between the 2. That made a believer out of me and my next chrono will be a MagnetoSpeed.

My ProChrono will be up for sale for a good price before long if you're interested

if the magneto and the ohler were close what did the prochrono read compared to the others I have a pro chrono just ordered a magnetospeed because broz says my chrono must be way off reading the loads I have tested out of my 7-300, my magnetospeed will be here Friday, the weekend I will be testing my loads thru each at the same time

 

[MontanaRifleman]

if the magneto and the ohler were close what did the prochrono read compared to the others I have a pro chrono just ordered a magnetospeed because broz says my chrono must be way off reading the loads I have tested out of my 7-300, my magnetospeed will be here Friday, the weekend I will be testing my loads thru each at the same time

The SuperChrono was inconsistent with the other two. I think the reason may have been because it was set up at 14' from the muzzles. After reading the directions more carefully, it is supposed to be set up 17' away from magnums and high velocity cartridges. The biggest inconsistencies were with the high velocity rounds. I did a little wright up on it in another Long Range forum which I'm pasting in below.

*********************

I processed the raw data that Broz recorded to calculate actual MV for the Oehler and SuperChrono. I threw out the first shot on the first string since the bayo had come loose. I added 9 fps to the Oehler readings and 8 fps to the SuperChrono readings to get actual muzzle velocites. Then I calculated the differences between the Oehler and Magneto and the Oehler and Super. Then I calculated the ES's for each string. I think the results were interesting.

ES' of the all the readings were fairly close, especially the last 3 strings.

The Super recorded lower readings than the Oehler with the 2 highest velocity strings. It recorded higher reading with the lower velocity strings.

The Magneto was the opposite of the above.

Both the Magneto and the Supper agreed more closely with the Oehler with the slower velocity strings with the Magneto being the closest.

The greatest Magneto/Oehler difference was 13 fps with many in the 1 fps category.

223

Oehler........ Magneto................ Super ............ O>M......... O>S
3309..............error........ ...........3240 …………………………….... -69
3322..............3335......... ..........3230 …………….. +13…………. -92
3303..............3315......... ..........3256 …………….. +13…………. -47
3325..............3337......... ..........3259 …………….. +12…………. -67
23……........……..22……….......……….29

6 BR

2830..............2829......... ...........2859 …………….. -1………….+29
2833..............2832......... ...........2859 …………….. -1………….+26
2822..............2820......... ...........2839 …………….. -2………….+17
2814..............2810......... ...........2836 …………….. -4………….+22
2824..............2823......... ...........2849 …………….. -1………….+25
19……........……..22……..........………….23

284 Win

2843...............2837......... ...........2862…………….. -6………….+19
2851...............2855......... ...........2852 …………….. +4…………+1
2866...............2860......... ...........2878…………….. -6………….+11
2834...............2831......... ...........2845…………….. -3………….+11
2837...............2836......... ...........2865…………….. -1………….+28
32……........……..29………..........……….33

338 RUM

3093...............3099......... ............3013…………….. +6………….-80
3109...............3117......... ............3036…………….. +8………….-73
3081...............3092......... ............3013…………….. +11…………-68
3097...............3105......... ............3009…………….. +8…………-88
3103...............3097......... ............3036…………….. -6………….-67
28…….........……..25……...........………….27

 

[Broz]

The SuperChrono was inconsistent with the other two. I think the reaon may have been because it was set up at 14" from the muzzles. After reading the directions more carefully, it is supposed to be set up 17' away from magnums and high velocity cartridges.

I believe this to be a type O. It was 14' not inches. Just for clarification.

Jeff