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Post by tdillinger on Oct 5, 2010 20:21:10 GMT -5
What is pressure trace tool exactly and how does it function? I saw recently that a thread was locked by admin for safety issues. I am all about safety but am curious if anyone here on this board has a pressure trace tool? Not trying to stoke a fire just curious.  |
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Post by ET on Oct 5, 2010 20:54:42 GMT -5
What is pressure trace tool exactly and how does it function? I saw recently that a thread was locked by admin for safety issues. I am all about safety but am curious if anyone here on this board has a pressure trace tool? Not trying to stoke a fire just curious. Hope this will satisfy your curiosity. www.shootingsoftware.com/pressure.htmEd |
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Post by rossman40 on Oct 5, 2010 21:00:28 GMT -5
It is a small foil strain gauge that is glued to the barrel. It basicly measures how much the barrel bulges. Not exactly milspec/ISO but can give you a rough estimate for backyard work and no drilling the barrel. Better then a CUP gauge as a CUP gauge will only show max pressure and are a pain to work with. A piezoresistor is another type of pressure gauge and nowadays with DoD testing two are used, a CUP gauge shows max pressure and verifies the data from a piezoresistor which shows the pressure curve. This requires two ports in the barrel
As far as who has one, RB had one and was showing data.
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Post by tar12 on Oct 5, 2010 21:05:41 GMT -5
$800 and your ready to roll.
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Post by tdillinger on Oct 5, 2010 21:12:34 GMT -5
It is a small foil strain gauge that is glued to the barrel. It basicly measures how much the barrel bulges. Not exactly milspec/ISO but can give you a rough estimate for backyard work and no drilling the barrel. Better then a CUP gauge as a CUP gauge will only show max pressure and are a pain to work with. A piezoresistor is another type of pressure gauge and nowadays with DoD testing two are used, a CUP gauge shows max pressure and verifies the data from a piezoresistor which shows the pressure curve. This requires two ports in the barrel As far as who has one, RB had one and was showing data. Is RB richard? i need to go back to the thread to find out if there were pressures, of which; what is the max pressure for a savage 10ml II with each type of barrel? $800 bucks is a lot of money to test. but if one has the time and ambition so let it be. |
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Post by Dave W on Oct 5, 2010 21:19:32 GMT -5
RB is Rick Bibby, there are numerous pressure traces in the Tips & Hints section.
I think Edge has the pressure trace equipment.
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Post by DBinNY on Oct 5, 2010 21:25:02 GMT -5
RB is Rick Bibby. There are plenty of his pressure traces of various loads in the tips and hints. I wouldn't go dropping $800 on the equipment right away. Our sabots tend to blow when pressures climb much above 40K PSI so in a sense, that will tell you when things are getting too hot. Just stick with the book loads and loads time tested by members and you will be fine. No need to reinvent the wheel as any number of proven loads are available here. As Ozark suggests, non-book loads are at your own risk. RB's "shooting and rocket fuels" website (link at top of page) has a good discussion on pressure so check that out.
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Post by DBinNY on Oct 5, 2010 21:25:45 GMT -5
Dave, you are too quick, or I'm too long winded.
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Post by Dave W on Oct 5, 2010 21:31:56 GMT -5
Dave, you are too quick, or I'm too long winded. Same ending, you're just more thorough. |
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Post by rossman40 on Oct 5, 2010 21:37:04 GMT -5
It is RBinAR, not Richard. As far as safe max chamber pressures something in the 40,000 range would be cool with the danger zone I would think being high 50s and above. Real hotrod centerfires like the RUMs and 338LM are in the 60s. But then again the curve has a lot to do with it, if the max pressure happens when the bullet is in a thinner part of the barrel you could end up looking like Elmer Fudd. If you have high muzzle pressure (pressure in the bore/chamber when the bullet exits the muzzle) felt recoil can be higher.
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Post by ET on Oct 6, 2010 4:01:21 GMT -5
Tdillinger
I can’t remember exactly what the rated YIELD strength is for the 10ML-II barrel but it’s slightly over 90,000psi. YIELD strength is the point where metal can be stretched/formed to another size and won’t return to its original shape. Example is a bulged barrel.
Now that’s providing the barrel has been properly quenched and tempered.
I agree with Rossmans assessment of usable pressure range.
Ed
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Post by pposey on Oct 6, 2010 5:30:47 GMT -5
with saboted loads though will the sabot not pop before geeting anywhere near overloaded???
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Post by edge on Oct 6, 2010 5:41:59 GMT -5
with saboted loads though will the sabot not pop before geeting anywhere near overloaded??? Has anyone ever bulged a barrel using sabots?  edge. |
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Post by pposey on Oct 6, 2010 7:13:40 GMT -5
I'm sure they have, but Has anyone ever bulged a barrel with a single sabot/single bullet load set on the intended load of powder without a ramrod on top? I don't know
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Post by deadeye on Oct 6, 2010 7:37:40 GMT -5
i would be willing to bet some have if a load did not crack off & if not reseated,i personally experienced a non-cracking load to be found approx 4'' down the barrel, had my second attempt went off without reseating i think it would act as an obstruction.lesson learned-always reseat(after 1min wait) if load does not go off
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Post by chuck41 on Oct 6, 2010 8:51:58 GMT -5
with saboted loads though will the sabot not pop before geeting anywhere near overloaded??? Has anyone ever bulged a barrel using sabots? edge. Every bulged barrel I have ever hear of was with sabots, including mine. Loading one complete powder/bullet/sabot on top of another will bulge a barrel every time and it's easy to do, especially if you are careless, forgetful, or stupid. (I'll let others decide which category I belong to)    |
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Post by edge on Oct 6, 2010 9:01:25 GMT -5
with saboted loads though will the sabot not pop before geeting anywhere near overloaded??? Has anyone ever bulged a barrel using sabots? edge. Apparently my humor was not apparent Sabots will NOT prevent an overload of pressure as evidenced by bulged barrels using sabots! A normal load by definition is one that would not exceed normal load pressure curves! Now, a warm barrel will soften the plastic sabot and compromise its usage and may cause a blown sabot which is NOT the same mechanism that bulges barrels. Does a sabot blow when you bulge a barrel, yes but not fast enough to save the barrel. As mentioned earlier in this thread a bulged barrel is caused by exceeding the barrel yield strength. Here are two traces: here is a fairly normal trace with a load that works in MY RIFLE!  Here is a load that Is a bit high on pressure Disregard the second spike as it signifies that the pressure trace disconnected and is not actual pressure!  Note how fast the second trace reached pressure. edge. |
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Post by tdillinger on Oct 6, 2010 9:13:31 GMT -5
Edge, were both traces using the same powder with different loads? Or was the second trace a different powder? Also was the same barrel used for each? was there any bulging from the second trace?I understand the graph very well thank you.
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Post by tdillinger on Oct 6, 2010 9:17:59 GMT -5
RB is Rick Bibby, there are numerous pressure traces in the Tips & Hints section. I think Edge has the pressure trace equipment. I cant find this section? |
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Post by deadeye on Oct 6, 2010 9:35:03 GMT -5
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Post by edge on Oct 6, 2010 9:40:32 GMT -5
Edge, were both traces using the same powder with different loads? Or was the second trace a different powder? Also was the same barrel used for each? was there any bulging from the second trace?I understand the graph very well thank you. These were completely different loads. No bulging, but also not a Savage barrel or a sabot that would work in anyone else's rifle This is my custom home built 45 caliber rifle built with a 1 1/4 inch diameter barrel and no barrel nut! edge. |
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Post by stubblejumper on Oct 6, 2010 11:30:15 GMT -5
I was looking at ET's link above and Edge's second pressure trace that disconnected reminded me of it: Has anyone here ever seen or experienced the "secondary spikes" in pressure that the sight describes?
They attribute it to a powder that is too slow for the bullet weight. I had never heard of this before. If their theory is true could it possibly happen in our ML's with slow powders and light bullets?
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Post by pposey on Oct 6, 2010 15:42:59 GMT -5
Oh I'm sure it's posible to bulge a barrel with a saboted load but I bet it would be pretty hard to do unless the sabot and bullet were not seated correctly or if there were not some other loading error,,
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Post by smokepole50 on Oct 6, 2010 18:33:56 GMT -5
Edge, Have you ever tested that load that Richard Franklin uses in his custom ML? It's 78gr of IMR4198 behind a swaged to fit 45 caliber 275gr Parker BE. It is supposed to produce 2950 fps in a 30 inch barrel. This is a custom 1.25" breech area Kriegger barrel in a custom action. I would not try this in your Savage!!!!! After you pull the trigger and you recover a few minutes later, you can go and pick up what's left of the deer......... ) Smokepole |
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Post by edge on Oct 6, 2010 18:57:04 GMT -5
No I haven't, but his load seems safe for a 458 win mag so I would not have a problem with it.
I am more into lighter weights and a bit more velocity with higher BC bullets.
edge.
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Post by Jon on Oct 6, 2010 20:22:10 GMT -5
+1
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Post by pposey on Oct 6, 2010 21:06:07 GMT -5
Oh I'm sure it's posible to bulge a barrel with a saboted load but I bet it would be pretty hard to do unless the sabot and bullet were not seated correctly or if there were not some other loading error,, and as luck or carma or fate would have it I just made that error and bulged my pac-nor,,,,,,I now leave this thread with my tail tucked! But it was a double load......not a single, correctly loaded saboted load |
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