Every now and then I stumble across a channel I have not previously seen but which I feel is worthwhile watching.
This is one
Extreme Reloading (https://www.youtube.com/@sdkweber/playlists)
One thing your eyes cannot do is measure pressure.
This is content from another reloader that doesn't understand that. Most of them don't. Feeling bolt lift, checking for ejector marks, looking at primers, these are not reliable pressure indicators, but everyone parrots everyone else about it, and the reason if simply that anyone can see a differenece in primers between loads, and knows what a sticky bolt feels like, so the general assumption is that really is how to check for pressure.
It is not.
This detracts from the content, now I can't rely on what he's saying, and I have to ask myself, what other useless information is being parroted ?
Quote from: big5ifty on Dec 01, 2024, 10:54 AMOne thing your eyes cannot do is measure pressure.
True -BUT - it has become .. "reloader-lore" even followed by people like Bruce THOM ( Bat Actions ) and Gavin Gear ( Ultimate Reloader )
WHAT does one use to accurately measure pressure ....
Instruments which are unavailable / or unaffordable in SA - except perhaps for places like ARMSCOR / DENEL
Seeing as you denounce the "eye-ball" method . WHAT do YOU use - to accurately measure internal ballistics pressure ?
Quote from: Newton on Dec 01, 2024, 12:47 PMSeeing as you denounce the "eye-ball" method . WHAT do YOU use - to accurately measure internal ballistics pressure ?
A 1/10,000 micrometer.
That said, it cannot be denied that a positive pressure problem by eyeball can not be ignored. A eyeball check is not a true measure, but it is surely a much needed check, or do we just ignore all the signs because they not high tech enough
I hit max pressure in my rifles with no visual indicator.
No flat primers, no marks on the case head, normal bolt lift.
Case web expansion tells me when the load is hot enough to stretch the primer pocket in just a few firings.
A micrometer is very far from high tech, it's on the same level of tech as a vernier.
Your eyes alone are no tech, and in most cases, when you see there is a problem, you are far past the problem threshold.
Most people in fact judge pressure just from bolt lift. They load to where the bolt gets sticky, then back off a bit. That works too.
The micrometer seems to work for me. I've got just over 600 rounds on my 375 RUM, and I've been re-using the same batch of 80 pieces of brass. The brass is still good. It is Norma brass, that may also be a contributing factor.
.Your eyes alone are no tech, and in most cases, when you see there is a problem, you are far past the problem threshold.
Most people in fact judge pressure just from bolt lift. They load to where the bolt gets sticky, then back off a bit. That works too.
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You are way past correct, I am only saying that we should not ignore the signs given on a platter by eye balling or bolt lift.
Quote from: Treeman on Dec 01, 2024, 09:30 PMYou are way past correct, I am only saying that we should not ignore the signs given on a platter by eye balling or bolt lift.
And neither should we trust that which we can't see as evidence of the lack of an issue. I've heard more than enough range Bubbas talking about how their above published data loads are A-OK because of the lack of observable overpressure signs.
On the YouTube thing, it's clear to me that many grownups have fallen into the trap of conflating popularity with competence in or even mastery of a subject. Having millions of followers is an indicator of being an entertaining video maker and not anything more.
Quote from: big5ifty on Dec 01, 2024, 04:46 PMQuote from: Newton on Dec 01, 2024, 12:47 PMSeeing as you denounce the "eye-ball" method . WHAT do YOU use - to accurately measure internal ballistics pressure ?
A 1/10,000 micrometer.
Apparently also been discounted as a TRUE and accurate measure of pressure >
Apparently
PRESSURE TRACE II is he ONLY real measure of internal ballistics pressure
It's a good thing Joyce Hornady and Vernon Speer didn't know this, or they may have just given up on producing their reloading manuals and not used the 1/10,000 micrometer in compiling said load data.
Quote from: big5ifty on Dec 04, 2024, 10:16 PMIt's a good thing Joyce Hornady and Vernon Speer didn't know this, or they may have just given up on producing their reloading manuals and not used the 1/10,000 micrometer in compiling said load data.
Neither of those two old timers had a neck tattoo much less a YouTube channel so you can safely ignore anything they came up with.
Quote from: big5ifty on Dec 04, 2024, 10:16 PMIt's a good thing Joyce Hornady and Vernon Speer didn't know this, or they may have just given up on producing their reloading manuals and not used the 1/10,000 micrometer in compiling said load data.
Was all they had then
It has been shown that those old reloading data tables produced HOT loads
Compare old reloading manuals to newer ones
Military and industry Still used the CUP system
This link will open a PDF file explaining the difference between CUPS and Piezzo-Electric methods
Ballistic Pressure Sensor Reference Guide (https://www.pcb.com/Contentstore/mktgcontent/LinkedDocuments/Aerospace/AD-BallisticPressureGuide_LowRes.pdf)
You can then look up what a .. UNIVERSAL RECEIVER and Proof barrels are.
The range of scientific equipment available to measure chamber pressure, and the merits of each, can be a long academic discussion which I'm not qualified for.
You must choose what you will use to determine where your load is pressure-wise, or choose to use nothing.
If you reload for rifles, you're going to encounter a sticky bolt, pierced primers, popped primers and case head separation. It's part of the process, and still happens after you've been learning to reload for a few decades.
No one in modern times that I am aware of still use copper units of pressure. It has been proven that there is no set factor for converting CUP to KPSI. Even SAAMI is in the process of changing all the old CUP specs to transducer generated KPSI.
As a matter of interest this what all this stuff looks like
Good Explanation;
Ammunition Pressure Testing (https://www.gunsandammo.com/editorial/ammunition-pressure-testing/458750)
In Action;
M2 Improved Universal Ballistic Test Barrel Receiver (https://www.zpvpro.com/product/ballistic-test-barrels-and-receivers/173/)
Watch the YouTube
Acquire One;
Small Caliber Universal Receiver (https://sydortechnologies.com/wp-content/uploads/Sydor-Small-Caliber-Universal-Receiver-Datasheet_050819-2.pdf)
Test Equipment (https://hsprecision.com/ballistic-test-equipment/)
Bill Wiseman Ballistic Test Barrels and Receivers (https://www.wisemanballistics.com/products/)
I am sure a good well equipped machine shop could make these tools