Caldwell Chrony

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Here is an example of what I was seeing.........load was increased 0.3 grains each shot.

2903
+11
2914
+45
2959
+8
2967
-1
2966
-16
2950
+26
2976

Try shooting more than one at a given charge, not every shot at the same charge is going to give you identical velocities. Shooting more might let you see the overlap.
 
But with the Caldwell, becoming obvious I need to work on setup and shooting process, and if such variation continues, will need to expand shot strings per load. What the method is trying to uncover is a series of incrementally increased powder charges that give you about the same velocity, which is an indication of an accuracy node. What I have discovered is that if you shoot those in such a way to ID the hole made by each shot (vs shooting as a group with no clue which shot is which), the accuracy node also shows up on paper. The three shot string that was ID'd by the chrony also showed up on paper, with the same three corresponding shots nearly hitting the same hole. Not sure if that was discovery of the accuracy node or coincidence. Only way to find out is to load a large set to same charge and see what happens.

Try mounting the unit upside down then the sun does not matter
 
I use a similar method to Livelife. I have box of CCI standard velocity 22lr that consistently shoot close to 1050fps from my 10/22 carbine. If using on a cloudy day or in the shade, the LED light kit really does make a difference. My first one didn't have it, the one I'm using now does and I have way less sensor "error" with the light kit.
 
As for the Satterlee method, it is predicated on single (but accurate) measure of velocity from a single round......fired from a group of rounds where powder charge is increased in small amounts. Chrony most often mentioned with this method is the Magnetospeed, which clamps to the barrel and measures velocity at the muzzle. Because clamping something to the barrel screws up harmonics, and thus accuracy, there is no need to shoot targets.

I do a triplicate Satterlee test for my PRS rifle. For giggles, I do hang an OCW type target out front. I’ve used a ProChrono Digital, LabRadar, and both a Sporter and a V3 Magnetospeed - both mounted to the barrel as well as on a free-floating rod mount.

Here, you can see plots of one of these triplicate tests with the corresponding targets. You can see within the table, as well as depicted in the chart, the variability among each of the replicants, some charges exhibited a Range (ES) of 2, some a Range of 28. This variability suggests that ONE shot of each charge isn’t sufficient to determine a representative speed for each charge weight, and such, one shot of each charge is not sufficient to truly define nodes. In this test, there are 3 nodes depicted. You can probably guess which node I chose to use for competition.

0BE44340-0DCE-46FF-AF2C-36A9FA4F8E16.jpeg

Target array is 41.0-41.8 on top row, L->R, 42.0-42.4 on bottom row.
0FD290C2-2B10-47F1-89EB-A792447C7FD9.jpeg
 
My Caldwell seems accurate, I get real consistent readings. Loads will usually be within 20fps of each other, so I assume it must be pretty accurate.
 
Lots of folks love pushing this rumor around, but he posted the opposite yesterday morning - he still uses his velocity trend method. He stated that he HAS implemented a seating depth node check first, and then runs the velocity curve.
Interesting, I have never seen any significant fps variances from seating depth other than the already present minor variances or so called white noise of the CG. Where does he publish his articles for reading.?
 
I do a triplicate Satterlee test for my PRS rifle. For giggles, I do hang an OCW type target out front. I’ve used a ProChrono Digital, LabRadar, and both a Sporter and a V3 Magnetospeed - both mounted to the barrel as well as on a free-floating rod mount.

Here, you can see plots of one of these triplicate tests with the corresponding targets. You can see within the table, as well as depicted in the chart, the variability among each of the replicants, some charges exhibited a Range (ES) of 2, some a Range of 28. This variability suggests that ONE shot of each charge isn’t sufficient to determine a representative speed for each charge weight, and such, one shot of each charge is not sufficient to truly define nodes. In this test, there are 3 nodes depicted. You can probably guess which node I chose to use for competition.

View attachment 1033530

Target array is 41.0-41.8 on top row, L->R, 42.0-42.4 on bottom row.
View attachment 1033531
Nice work VT, very well done.
 
I have a Caldwell & a Comp Elec.
Both list about the same numbers.

Shots on a new battery? Have a spare, but I've run 5-6-7 shooting trips.
Maybe 75-100 shots each trip.
Just remember to turn it off when you're done.
 
Well Im not giving advice anymore.( except for post #18:oops: But a 270 Winchester is a far cry from a highly tuned 22 pound custom Dasher.
IMO VT is exceptional so if a fella wants those numbers your going to need clean ignition and consistent combustion to start with.
 
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The triplicate version of Satterlee does seem to be an improvement. Looking at the graph, singles could give all kinds of indications......as would the targets by themselves. But the combination of both looks to clear things up. I am assuming you went with 41.6.

As for seating depth, as a newb to loading for rifles, I have yet to see a definitive resolution as to which comes first......powder charge or seating depth. On one of his seating depth tutorials on utube, Eric C where he demonstrates group sizes going large and small by changing seating depth only, he goes so far as to mention that one could even run the three shot seating depth ladders to fine tune factory ammo. If that is true, then a ladder test to find out the optimal combination of powder charge and seating depth would require several hundred shots.....starting at a seating depth just off the lands, and then a triplicate or greater load test for that seating depth, back it up a notch and do it again. So at least 25 to 30 shots x at least 6 to 8 seating depths. If you one did try that, my guess is what would show up are numerous combinations that give the same group size.

So my plan going forward was to pick a seating depth.....in this case, about 0.020 greater than the seating depth for the bullet being loaded (from the manual), which gives me 6 to 7 seating depth increments of 0.003.....as that is often enough tests to see the accuracy nodes shrink and swell. Then work up and optimal powder charge for that depth, then return to depth to see if changing it fine tunes it. If what I think is going on is going on, likely as not, my starting depth will be one of my accuracy nodes.

To stay grounded, I also need to keep reminding myself this is being loaded for deer hunting in sporter hunting rifles. So while sub-moa would be nice, it's not absolutely necessary. Any and everything I've loaded so far would have been good enough for this use.
 
In my experience the cheaper units either work well enough, or not at all. I've seen tests where they compared velocities from this and similarly priced units with some high end stuff and the results were remarkably close. Certainly close enough for must recreational shooters.

Mine works well enough for me the vast majority of the time and when it doesn't work the numbers I get are nonsensical and obvious. They are very sensitive to light conditions and if conditions aren't right you aren't going to get usable numbers. And I've had other times where everything seemed right, but the numbers I get made no sense at all. Then the next time out it would work perfectly.
 
I have both and older Samsung Android phone and new iphone. Latter won't work with this model, which does not have wireless transmitter. Have never been able to get the Android version with cables working either. There appear to be some settings to get right in the phone setup, and I gave up trying. So with my analog mind, living in a digital world, I take a pencil and notebook and write down my readings in a table. With a nod to modern times, it is a mechanical pencil at least.

So installed new battery, then set unit up on a tripod in shade of building on a bright sunny day, test fired pellets from a springer air rifle. All shots within +/- 5 fps, which may well be close to what the gun was doing. Also went over instructions again, and sun shades not needed on an overcast day, or firing from the shade, except it does seem to help with placement of the shots. With a scoped gun, probably best to have crosshairs set with sun shade in view above......that way bullet passes in middle or upper half of the field. I have been shooting too low......too close to sensors. Not close enough to hit unit, but perhaps too close to get good reading. I tried a few shots that just barely cleared bottom of sun shades and not only did it pick those up too, velocity was the same.

So climbing the learning curve.......and now trusting the unit if I get setup right.
 
But a 270 Winchester is a far cry from a highly tuned 22 pound custom Dasher.

Conceding generally to the point - that target and velocity curve was fired with my Seekins Havak in 6 creed, in its factory form. A 7lb bare rifle with a heavily fluted magnum sporter (“light tactical”) barrel, McMillan Game Warden stock - unmodified, a cheap Hornady stock pack with a foam rubber riser tucked beneath, and a Timney 510 trigger. It’s been rebarreled, re-triggered, and weighted down since then, but that test was fired by nothing more than an overpriced hunting rifle.

IMO VT is exceptional

While flattered, I’m not quite sure how to swallow that - as I mentioned above, that test was fired with factory hunting rifle sitting on a Harris bipod, using cheap Hornady Brass which was loaded on a $125 Lee Classic Turret press and a $100 arbor press, WLRP’s, developed using a popular abbreviated load development method easily found online, and even the charge weight span used in the first test was passed to me by a fellow shooter standing in a parking lot after a match: “hey VT, I heard you bought a 6 creed, are you using Hornady brass (since it was the only factory 6 creed brass at the time)? Stick 41.5-42.0 grn H4350 under a 105 Hybrid 8 thou off of the lands, you’ll find a node in there.” If any of that is exceptional, it can’t really have anything to do with me.

if a fella wants those numbers your going to need clean ignition and consistent combustion to start with.

That’s really it. Help ensure bullets leave the muzzle the same, and then it’s only the wind and the shooter which can cause problems on target.

Sorting by firing, annealing optional, Hornady brass, no neck turning, bushing FL sizing, mandrel expanding, seating on an arbor press. Nothing terribly uncommon, and definitely nothing I developed. I do it this way because it’s simple and effective, and I shoot PRS because I don’t need anything more than this (and because I like the broader practical application than 100% bench or prone).
 
I am assuming you went with 41.6.

41.7 in that barrel - the consequence above 41.8 was steeper than that below 41.6, but 41.7 sat in the middle, and with my powder dispensers, I could be certain my charge was within the node.

I used a ProChrono Digital for years - about 5yrs borrowing my uncle’s when needed, then bought my own around 2004, and used it for around 13-14 years before I got my MagnetoSpeed (Sporter then traded to V3), and then my LabRadar. For match competition, a downrange chrony isn’t an option, but the precision of the ProChrono Digital was sufficient for what I needed.
 
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