Recent content by gregmark24

Redding states to size down no more than 008 per step. Perhaps try an intermediate bushing first? If you remove and shake the die, does the bushing ever so slightly move/click inside (it should)?

The Faraday cage is for electric fields—high voltage and low current. Minimally effective for magnetic fields (just the opposite. High current and low voltage).

You’re likely within what is called the “near field” at wavelength/2Pi or lower. There are two types of fields. Electric (high impedance) and magnetic (low impedance). Electric fields are easy to shield and magnetic fields are not. Your high current and low impedance situation for induction...

I have three. The Hornady is referenced to the datum point only. Basically, a 008 chamfer and a cylinder. I use a go gauge with length embossed on its side. Knowing that, and then measuring after zeroing calipers gave me the 008 aluminum gauge chamfer to extract absolute values vs SAAMI...

Ditto. I tried different apps for years and settled on GAIA for all except off road on ATV. I paid about $75 for 5 years for more functionality (maps and shading access, and exporting GPX I recall). I use Google Earth in tandem a lot. Avenza for ATV’s I find that the elevation gain is...

Exactly. You can use a Hornady headspace comparator, make an absolute measurement of the go gauge and the difference between your calipers’ measurement and the label on the go gauge is the chamfer of the comparator. Mine is 0.008”. So, when I add 0.008” to any measurements with that...

I, for one, think Hornady has a good argument. I have a 243 that seems to prefer a given powder charge and not prefer another. I’m going to load up 20 of each and put Hornady’s results to the test. Chronograph and POI both

Here’s the Hornady graph at 0.2 GN increments. Dismiss the holes between those peaks.

In reality, and in my case, it should allow a direct comparison between similar velocities measured on my LabRadar, and my buddy’s new Garmin. But, though average and ES compare well, SD does not, with the Garmin often besting the LabRadar by an SD of 2. So, if you’ve got an ES and SD goal for...

I beg to differ. Garmin calculates it WRONG. First, we're assuming a normal (bell-shaped) distribution. Not a bimodal, triangular, square top distribution, etc. Most of us are shooting smaller samples of data, well under 30, and more likely 5 to 10 shots looking for an average velocity, ES...

Yep. You're spot on. By using a "sample", you're admitting that you don't have all the data from a normal population, and your SD should be worse. Some almost 50 years now since my statistics class in college, I still have occasional dreams that I'm going to my statistics final exam, but...

I didn't find IHFarmer's post, but in another thread, we've discussed this Garmin SD issue extensively. Garmin calculates (an optimistic) SD for small sample sizes. Less than 20. For 3 shots, the SD from Garmin will always be too optimistic. For 50 shots, it will be correct. As an example...

Yep. As I had brought up early in this thread, your results are very similar to ours. LabRadar and Excel calculate SD for small groups as a small sample size, but Garmin calculates incorrectly, for a large population size. My second polite notification to Garmin a month ago regarding this...

I think it does make a difference. If you're shooting 3 rounds per powder development charge, the difference in reported SD is huge with the correct vs Garmin (optimistic) results. If you use a spreadsheet after the fact, or a LabRadar, you'll get correct (less optimistic..) SD's.

I contacted Garmin about the STDEV.P vs STDEV.S what, two weeks ago? I've never gotten a response; that's really disappointing.