Measuring chamber pressure

[ElJay]

In a thread regarding questions I had about primer cratering, some responses talked about measuring chamber pressure. itchyTF included this link to one such device.
http://www.shootingsoftware.com/pressure.htm
Does anyone have experiences with the devices or have comments? I am not to the point in y reloading career where I am confident that I can safely read signs of over pressure. Such an approach might help/

 

[bigedp51]

Read below, PressureTrace will generate PSI estimates without calibrating the system to a factory load!

If you shoot a factory loaded cartridge in your fire arms and use it as your base line visual guideline (reading the case for pressure signs) you can visually reload cartridge cases and be safe.

In plain English you need this device like you need another hole in your head.


PressureTrace will generate PSI estimates without calibrating the system to a factory load!
Using factory ammo or a load reference with known pressure to verify results is always recommended but we recognize each chamber will produce different pressures and wildcatters may have nothing for comparison. PressureTrace uses both thick and thin wall open vessel algorithms to provide reasonably accurate pressure estimates from barrel, chamber and brass dimensions. Unlike other products PressureTrace does not require a large correction "fudge" factor for pressure held by the brass but the system can still be calibrated to match other pressure systems. For safety, NEVER exceed the loads in a reputable load manual.

Below is a chart from the link at the bottom of the page about the 5.56 vs the .223. The pressures were taken with the equipment you listed in your post above. Please note it was calibrated with a factory loaded .223 cartridge and the chart pressure is approximately 49,000 psi and the rated chamber pressure is 52,000 cup or 55,000 psi. This means the strain gauge and test equipment is reading 6,000 psi below the rated chamber pressure. The majority of factory loaded ammunition is loaded below the rated pressure for a given caliber BUT how close is this guesstimate to actual pressure?

Bottom line, I have been reloading for over 45 years and I have NO desire to purchase this pressure guesstimating equipment. Reloading is like playing Black Jack, stay light and beat the pressure dealer.

5.56 vs .223 – What You Know May Be Wrong

http://www.luckygunner.com/labs/5-56-vs-223/

 

[navyrad8r]

Eljay,
I have been blessed to have an ohler 43 that can accommodate a transfixed for guestimating chamber pressure... With that being said, go with biged, good Reloading manuals, and ask questions to the "ol timers" and ballisticians. With all that info you should be plenty safe. Unless you are wildcatting from scratch, or loading risky recipes you don't neeed that kind of dedicated gear. Just my .02
Cheers,
Doc

 

[SmokinJoe]

And the best appraisal of max pressure is still a good micrometer and the brass you are using. Regardless of published specs of max pressure, it is the max pressure your brass will tolerate that really counts. Results with different brass will vary, sometimes by quite a bit.

 

[6BRinNZ]

And the best appraisal of max pressure is still a good micrometer and the brass you are using. Regardless of published specs of max pressure, it is the max pressure your brass will tolerate that really counts. Results with different brass will vary, sometimes by quite a bit.

Joe - what is your method for checking expansion and what tolerances do you use?...just asking...not going to argue.