Home Forums Hunting & Shooting Ask The Gunwriters at home load data

the information coming up in the thread I started about the differences in manuals leads me to another question related.
is there any kind of at least somewhat affordable home devices to help you determine pressures? rather than reference material and chronograph

You can order a PressureTrace II for $800.

https://www.shootingsoftware.com/pressure.htm

"Somewhat affordable" I suppose is relative though. As far as anything that gives accurate readings for firearms pressure it's likely to be as affordable as you can get.

The forum member, denton, has spoken about his usage of one and is the same Denton referenced on the webpage for the link.

thanks that's exactly what I'm looking for something like that. way cheaper than I was expecting too.

Just for the fun of it, research the (old and no longer in existence) York-Cantrell system.

While not as scientific as a PressureTrace, I use Gordon's Reloading Tool (GRT) to give me an idea. As they say, crap input == crap output. With that said, taking actual measurements of velocity, volume of fired cases, OAL/case length and bullet length will get you close to understand pressure. GRT is free for now and has a decent community to assist should you have questions.

https://grtools.de/doku.php?id=en:doku:install

I have not checked QuickLoad against actual measurements, but there are those that say it will land you within a percent or so if you use actual measurements of case capacity, etc. instead of taking the defaults. It's cheaper.

PressureTrace is kind of cool. You'll need to glue a strain gauge (~$10) to your barrel, a bit away from the shoulder of the barrel, and in the middle of your cartridge case. Either JB Weld or crazy glue with tiny bits of rubber in it will work. Hook up to a laptop, and you're off to the races. When you get done with your load development, remove the strain gauge.

For best results, temperature of your barrel and ammo should be as constant as you can manage.

are the strain gauges reusable ? or a new one each time you glue it on your barrel ?

It's pretty hard to get the gauge off without ruining it.

Most people mount them on the top of their barrel. I have been known to mount them on the bottom, then drill a small hole in the stock and finish it with a plastic plug. That way, the gauge is permanently installed.

Do be careful about providing some way to protect the wires and connector during recoil. A bit of electrical tape will do the job.

Denton,

Are you using the strain gauges from the same people that sell the PressureTrace or sourcing them from somewhere else? I was surprised to see that they charge $109 for three strain gauges with no glue. $36+ a strain gauge for a one time session seems a little steep, at least for my own uses.

excellent , 👍

I buy my gauges from the same place PressureTrace does. Haven't needed any for quite a while. Trying to remember the source and model number.....

Inspires me to measure every door and window in my homes to make sure they are perfectly square.

Micro-Measurements, Vishay Precision Group gauges? Most likely a linear gauge as I see 2 lead wires for the gauge. Not a stacked rosette strain gage?

Could be strain gages sourced from Omega Engineering?

Bingo! Went looking for an alternative on eBay, and found the exact item... basically 5 for $30 with shipping. micro measurements

You will have to make up a little connector like this one:



I think it is a computer edge board connector for audio or something.

OOOOPS! eBay item is not the exact replacement. Close, though.

For the CEA-06-250UW-350 gage: the 250 is the grid length in inches. 0.250".

For the CEA-06-062UW-350 gage in the ebay link above the grid length is 0.062"

I don't know if the grid length matters to the PressureTrace gage conditioning for the gage. Since both gages are 350 ohm resistance might not matter?

MM data sheet for CEA-06-062UW-350: https://docs.micro-measurements.com...NTU2Mjg4OS4yLjEuMTY3NTU2MzM4Ni4wLjAuMA..

MM data sheet for the CEA-06-250UW-350: https://docs.micro-measurements.com...NTU2Mjg4OS4yLjEuMTY3NTU2MzYxOS4wLjAuMA..

Link to MM gage finder: https://micro-measurements.com/pca/...YWx5c2lzX3Jlc2lzdGFuY2UiOiIzNTAifQ%3D%3D

I've applied plenty of these gages over the years. Spent a week at Vishay training on employers dime. Tedious job laying a bunch for data collection.

Get a piece of pipe and cut some rectangles of drafting mylar or other plastic. Practice getting the gauge on straight and flat with no air bubbles underneath before you try putting a gauge on a rifle. I usually stretch some electrical tape over mine while the adhesive sets.

The Vishay gauges are sealed, top and bottom. A lot of inexpensive gauges are not sealed on top, but a light coat of fingernail polish fixes that. Their gauges are also temperature compensated for thermal expansion of steel. Other models are temperature compensated for other materials, such as aluminum.

denton,

Good advice, of course!

I have never purchased a Pressure Trace, partly because Charlie Sisk did, and we experimented considerably with it on his indoor, temp-controlled range when his shop was in the Houston suburbs.

Also had access to the Western Powders piezo-electronic indoor, temp-controlled test facility for years. In fact, was offered a full-time job in their test-lab around 20 years ago--but was making more than they could afford.

The major deal is temperature-controlled conditions for both pressure and velocity results--along with light conditions IF a light-screen chrono is used.

John