Load Pressure

pjlukey

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Joined
Jul 5, 2020
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Location
Bloomington IN
I've decided that I would like to profile load pressures. I hope to follow SAAMI protocols, and Mr Google suggests there might be affordable equipment available for this. However, I prefer to ask this august assemblage for advice rather than simply putting all my trust in my own naive hopefulness.

So, how might I best inform myself on this matter?

-Paul Lukey
 
There are software programs that can help profile a lot. It needs a lot of fine tuning. But worth the time learning.

SAAMI lists 3-4 places they use that will certify pressures for them but you'll have to sacrifice a barrel or two in the process.
 
Friend of mine in Colorado has & uses the RSI Pressure Trace.

You can get more of the sensors if wanted/needed. These glue on to the barrel above the chamber. Instructions are included for placement.

Does really good at graphing out the pressures.
Was really surprised at the pressure spikes you can get with low charges!!

Real eye opener!!
 
I have read about pressure spikes -- some of them dangerous to the extent of destroying actions -- from using low charges. Thanks, std7mag, for mentioning that.

As for the RSI Pressure Trace, it is an intriguing technology. You don't have to put a hole in your chamber to get a measurement on a copper crusher, and the results are instantly available. The best part is, you can use the barrel again and again, and even move the pressure sensing tape from one barrel to another. This will doubtless be the technology of the future. Which means, I suppose, that cheap knockoffs will soon be available.

I for one would like to hear more about the technology from someone who has used it.
 
Yeah, the Pressure Trace shows the difference between the nice pressure curve that we look for vs a pressure spike.

He repeated up a load that i had tried in my 7mm-08 when i was first starting out reloading. I can't remember which powder i was using at the time, but went with a published starting load.
Harsh recoil!!
He was able to show me how the pressure suddenly spiked vs curved and what the pressure was. (Almost 70,000 psi)
 
The pressure trace has been around for quite a while--- and it's affordable.

Most people won't spend the time or money to test it though.

I ran into the equipment when I was testing higher bc, heavier bullets with not normal powders in 6.8spc. ( a fellow forum member owned it)

It won't matter to anyone on the internet if you "prove" your load is safe using this equipment--- naysayers still tell you if your muzzle velocity is faster than book loads you are unsafe.

A few 6.8forums members came up with a "long load" 130grain using lvr powder. I get 2760fps from this load in a 20" barrel--- I know it's safe because it was tested--- yet people will tell you all day long you are over pressure.

It was peace of mind for me to know it's safe in such an of the wall load.


To me, if you are going to push the book data or do wildcats it would be good to have

I'd love to see some of the hammer load data "proven" with the technology
 
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The pressure trace has been around for quite a while--- and it's affordable.

Most people won't spend the time or money to test it though.

I ran into the equipment when I was testing higher bc, heavier bullets with not normal powders in 6.8spc. ( a fellow forum member owned it)

It won't matter to anyone on the internet if you "prove" your load is safe using this equipment--- naysayers still tell you if your muzzle velocity is faster than book loads you are unsafe.

A few 6.8forums members came up with a "long load" 130grain using lvr powder. I get 2760fps from this load in a 20" barrel--- I know it's safe because it was tested--- yet people will tell you all day long you are over pressure.

It was peace of mind for me to know it's safe in such an of the wall load.


To me, if you ate going to push the book data or do wildcats it would be good to have

I'd love to see some of the hammer load data "proven" with the technology

Hi I did a similar thing except loaded 135gr Matchkings in the 6.8 in a rem 700 20" barrel. Loads were super sonic to 1000 yards. The little case duplicated 303/270 load data. Was an interesting experiment.

Cheers Bill
 
I've decided that I would like to profile load pressures. I hope to follow SAAMI protocols, and Mr Google suggests there might be affordable equipment available for this. However, I prefer to ask this august assemblage for advice rather than simply putting all my trust in my own naive hopefulness.

So, how might I best inform myself on this matter?

-Paul Lukey
I've used the RSI pressure trace system it works well, I bought a couple of extra strain gauges. The most important aspect of the whole setup is getting the strain gauge when it has to be be for accurate readings there's not a lot of room for error on strain gauge placement.
Get you a bar of CERROSAFE® CHAMBER CASTING ALLOY so you can get a good measurement

You will be truly amazed at the information you can get from this system
 
Very interesting. What is $800 these days? I have a 6.5x55 Tikka that I load a little over book since its a modern action and just a sweet little gun. I have all sorts of magnums but the last three deer I shot died with the Tikka T3 Lite. But I feel I could get more out of it, just afraid to push. I've never trusted "pressure signs" etc....
 

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