16ga.com ~ View topic

Joined: 08 Feb 2009 Posts: 1310 Location: Western WA

Obtained a RSI Pressure Test II system for evaluating 16 ga loads. Software installation and hardware integration was troublesome due to typical Windows torment with firewalls, com ports, etc but eventually completed. Attaching strain gage to M12 16 ga and connecting to wires and cables was straightforward. Pressure Trace II hardware module is well designed and high quality. It was inspected by a pressure testing engineer who was satisfied with its specs and build quality.

Bench testing was successful and confirmed proper operation. Range testing commenced per instructions and initially showed consistent results. Testing was suspended after light rain and cabling problems created difficulties.

Usage plan is to generate relative pressures of reloads compared to factory loads, not absolute pressure values. First results show this looks feasible. Pressures look well below expected values but per RSI feedback, is not unusual and could be due to adhesive, my reuse of old strain gage, or other scaling factors. The software has scaling correction available but I’ll use as is.

The chart shows two loads (2 shots each), a Rio 1 oz 1300 fps factory shell, and my 2 1/2” 7/8 oz 1185 fps skeet load using Clay Dot. The peak pressures are similar but the Rio load is slower burning. A Fed 1165 fps game load is similar shape to my Clay Dot load.

Other than the scaling, the data are clean, logical, and consistent. I’m declaring victory.

Next step is to replace old strain gauge with new item, and conduct more benchmarking with factory loads, which I may (or may not) send out for lab testing. Then compare to my recipes, especially my favorite Red Dot skeet load.

I’ll entertain questions and comments.

V/R
B.

Joined: 30 Sep 2019 Posts: 145 Location: Colorado

Bravo, sir. Thanks so much for pursuing this and posting results. I’ll be following your subsequent posts and definitely be interested in load recipes.

Joined: 21 Mar 2019 Posts: 523 Location: Texas

what windows version are you running? good update, appreciate the hard work. I would like to do the same, just haven't pulled the trigger yet.

Joined: 04 Mar 2019 Posts: 1844 Location: Central ND

At one time, I really wanted to get the Pressure trace system. But after I really thought about it, I realized that I wouldn't use it enough to bother with.

It is a good system and that isn't my opinion of it. I did a lot of asking around and everyone that had a Pressure Trace liked it.

Good deal Brewster11 I think you will have some fun!!

You will also learn a lot and when you try to explain it, folks will basically ignore you and tell you that you don't know what you are talking about, even after you present actual data and not wives tales. LOL I am kidding and being serious and I am smiling the whole time it took me to post this response.

Be well!!

Do yourself a favor. Buy primers, powder, wads and once fired (not new hulls) hulls and keep them separate. The components should be for a 1 oz. lead load maybe 1250 velocity and use a faster powder (but not Green Dot it's too close to being too fast.) Unique, Universal, N320 is more like it. Make up at least 200 rounds and send 10 rounds to Tom Armbrust and tell him what the loads are for(I wouldn't send it to anyone else). Get the Velocity and Pressure of that load and then each time you setup the Pressure Trace fire 5 rounds, 10 if it makes you happier. If things are correct, the loads should average consistently each time you setup the system. If the numbers are off you know that you have a problem and deal with it before you waste a lot of work and components. DO NOT try to make the reference load 'low pressure', you want a robust load that performs. Wimpy loads are not your friend when you are trying to get information on how the system is performing, which is what a reference load is all about.

If you keep the extra components in a cool, dry area you will be able to reproduce this reference load many times.

Way back, Tom and I had a reference load that I made up with the same lots of all components except the shot and we each shot that load every time we setup. We sent each other the results to be sure we were good. It works and it saves a lot of guessing. I am not in favor of using factory loads for this purpose.

I use a reference load for each time I setup my chronograph.

Yes it is an extra expense and it takes time to weigh powder and shot for each round, but down the road you will be thankful you put in the time.

Member Joined: 06 Oct 2007 Posts: 2349 Location: West MI

Interesting. Thanks for chronicling your experience with it so far. Looking forward to more as things progress. IF I ever retire might "pull the trigger" on one.

I find the ramps in from -0- to approx the 0.3 mark intriguing. What initiates -0-? The input from the strain gauge sensor? A switch on the trigger?

Joined: 08 Feb 2009 Posts: 1310 Location: Western WA

Thanks all for the responses, it’s been an interesting and hopefully promising project.

I’m running Windows 10, which is a challenge in itself, especially when running together with a separate system. But once it is set up correctly, it runs reliably if operated per instructions.

Putz463, the data collection is triggered when the strain gage signal exceeds a pre-set threshold, which is adjustable by the user. The data is recorded every ten millionths of a second. The data module is a separate box and runs its own software. It’s a sturdy high quality unit with many options for setup and operation.

Unfortunately there is some disappointing news. The owner and inventor of the Pressure Trace II is retiring at the end of the year. Production has already ceased and the website is shut down. The owner can be contacted via phone, and has been extremely helpful and forthcoming in our conversations. This will continue only through years end. Parts and assistance will be available thereafter from another company.

If anyone currently owns a Pressure Trace II system, I suggest holding on to it. It will continue to be a valuable tool for reloaders, especially 16 ga. And if you happen to come across one, snap it up immediately as it will be functional and useful well into the future.

V/R
B.

Great job Brewster11

I -- The Great Procrastinator -- purchased the original Pressure Trace product in 2007, and "never got around to it" -- dang me. However, last spring I started a conversation with the guy that runs Recreational Software, and he indicated I might want to first see if I could get my old software to work before buying the latest version. Pressure Trace II is so much better -- modern 64 bit CPU requirement, features, construction, etc. -- all better. The old version I have needs a 32 bit CPU and a Windows version no later than Windows XP Pro. So I bought a refurbished old computer loaded with XP Pro and had problems loading the drivers to run the data acquisition hardware. I worked with the Recreational Software guy to try to get it up and running, but we ran out of "experience" on both our parts -- dead end, it seemed. Then in September, on advice of one old workmate, I teamed up with another former workmate who actually is a computer whiz as well as a whiz on about anything else. We worked on it all morning, no success, but got a good idea what was going wrong. After I left he got it to work!! The next day I left for Arizona, to pack up the house there and move to Florida. Can't wait to get back to Minnesota next spring to strain gauge my home made "proof gun" and get some data.

I intend to send carefully loaded shells (10 each) of two or three peak pressure levels to Tom Armbrust to get some reliable pressure data. Then using those same loads in my own "pressure gun" I want to see how data from my own pressure gun correlate with Tom's. Tom's will be the standard. All shells for this comparison, both those that go to Tom, and those I run through my own gun, will be made at the same time, in one batch -- same batch of primers, powders, wads and new hulls. If my pressure gun correlates fairly well, then I can use it to quickly verify that shells I load for my damascus guns have suitable peak pressures.

No, this does not obviate the need for a proof test of my damascus guns, to see what peak pressures they'll tolerate. Once that peak pressure level is determined, I can use my pressure gun to verify that any future load stays under that.

Best Regards,
Tony