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DIY Proof test ammunition for pistols.

Tool Steel

Plastic
Joined
Mar 9, 2012
Location
Lisboa, Portugal.


Dear Sirs


I would like to hear your opinions about " Home made proof test ammo ", is the pressure increase directly proportional to the propellant weight increase ?


The Wikipedia page about proof testing pistols say :

..." The standard proof of pistol, revolver and rimfire cartridges is performed with overloaded cartridges that produce 30% more chamber pressure than the C.I.P maximum pressure limit for the same cartridge in its commercial version. "

I would like to know if I can make my own proof test ammo by adding to the existing propellant in one " normal " commercial ammunition ( not +P ) more 30% propellant charge ( by weight ) taken from other similar ammunitions.

For example :

To create a .22LR proof test ammunition, I would open a .22LR standard velocity ammunition, measure the weight of the propellant, calculate 30% of the measured propellant weight ant then add that amount ( taken from other .22LR standard velocity ammunition ) to an existing .22LR ammo, and close the case with the original projectile.

I am not sure if the increase in pressure is directly proportional to the extra propellant weight added or the pressure increases exponentially.

I would appreciate very much any help about this subject.

Thank You.
 
What you propose is not a good idea. Slight changes in seating depth or powder charge can make a big difference in pressures when you are using a case that is nearly full of powder. I think it is a safe bet that increasing powder charge by 30% will increase pressure by much more than 30%.

There is information on a few proof loads here; Biggerhammer.net - Miscellaneous Firearms Technical and Training Manuals http://www.biggerhammer.net/manuals/pdfs/tm43-0001-27.pdf

You can also obtain Quickload software to calculate pressures.

Ranb
 
The answer to your question is NO! Pressure is not directly proportional to the amount of powder. With the wrong powders for proofing a very small increase will get you to dangerous overload. As the pressure increases with any powder, burning rate increases which increases pressure, which increases burning rate.
With that being said for proofing a pistol or rifle with no published proofing info a available, I would look in your standard reloading info and look for powders that relatively large changes in the charge weight do not make large changes in pressure. In an 30.06 I would use that powder with several grains extra. On a .25 automatic it may be tenths of a grain extra.
I expect better information will follow on making proof loads as my expierence on this is next to zero.
 
Its a redundant question. You can not estimated load pressures. You have to measure them. That's why companies charge you money for reloading books. Firing proof loads in a gun is dangerous and it is VERY hard on firearms. If you have a legitimate reason to proof test firearms you can buy proof rounds from Remington Arms or many of the other manufacturers. I have fired hundreds over the years in controlled situations and they are nothing more than a severe handload. If you want to spend $10,000.00 I understand Fiocchi has some very novel piezoelectric pressure sensors for sale. With one of those and anther $100,000.00 you will have what it takes to build all the proof loads you care to make. To what end, I have no idea. Firing a firearm repeatedly with proof loads will destroy it and at the very least make it unsafe. Proof rounds operate at the very edge at which metal begins to move and flow. When metal begins to move and flow bad things are happening! If a gun has been proof tested, IT SHOULD NEVER BE SUBJECTED TO A PROOF TEST AGAIN. Unless absolutely necessary.

Proof loads were originally designed to test for imperfections in steel and heat treatment, not design. In this day and age there is no reason to proof test firearms. Its simply a carry over from older times and in many plants its no longer practiced.
 
This sounds like a VBI... Very Bad Idea.

There are lots of variables that contribute to the actual chamber pressure when a round is fired.
You need to control all of them within very narrow tolerances to avoid blowing the piece up in your face.

- Leigh
 
Do not under any circumstances try to make your own "proof loads" you will probably wear the "proof" of it for the rest of your life. I have seen the results and it is not pretty. My eyesight is bad at age 57 but two eyes are better than one.
 
All of the above is true. A 30% overload would be way over proof pressures and you would likely have a cloud of broken parts if you were to fire such a cartridge.
 
Thank you very much to all of you who shared your opinions.

I understand that the use of proof loads is dangerous, must be done remotely in a test stand and is to be done only one time, after a weapon is manufactured at the factory.

But those people who produce their own barrels, or the companies that sell barrels, don't proof test them ?

In my case I would be interested in proof test ( first time ) a .22LR rifle barrel and a.25ACP pistol barrel.


Thank you very much for your time and attention

Best regards.
 
All of the above is true. A 30% overload would be way over proof pressures and you would likely have a cloud of broken parts if you were to fire such a cartridge.

Are you sure about that ?

Look at the Wikipedia page about proof tests, under the paragraph - Proof testing in C.I.P. regulated countries


Link: Proof test - Wikipedia, the free encyclopedia


Quoting Wikipedia :

..." The standard proof of pistol, revolver and rimfire cartridges is performed with overloaded cartridges that produce 30% more chamber pressure than the C.I.P maximum pressure limit for the same cartridge in its commercial version "...
 
As I have already stated most newer arms companies do not test proof guns. Shillen, Lilja, McGowen, Apex, Rock and none of the other custom barrel makers ever do. I know first hand from contacts I have in-house that Remington Arms still does and Sako and Tikka also test proof. But its just a product leftover from a bygone era. It serves no real function any longer. Proving was a requirement before we understood steel making and when we were judging heat treatment in poorly lit foundry's by the color of the steel. Some governments still require military weapons to be proved but in a lot of cases military firearms are not made to the same standards as sporting equipment. So there could be a little validity in having them proved.
 
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I guess the question is "what is the point of you testing the action/barrels with proof loads?"

Are you designing a new/novel action or barrel design and wonder what safety factor you have before failure. If that were the case then I can understand overloading, perhaps to the point of total failure. But regardless you would be destroying your testing model.

If you are testing something that you made and want to continue to use it then I would think you would be better served by firing 10-20 full power commercial rounds from a remote firing position and see if the firearm fails. What do the cases look like? How have the cases changed in dimensions? Has the barrel's diameter grown? Have any dimensions changed that indicate deformation in the firearm?

As previously mentioned I would be more worried about damage done by a proofing load that would have never occurred if only standard full power ammo was used. Damage that may prove to be a weak point for future failure.

Perhaps someone else has a different experience they can rely. But I would not think if a firearm survives 10-20 full power shots that it will suddenly turn into a hand grenade with the same ammo in later shots. Something may deform/crack/bulge, but a total failure without a warning would seem highly unusual. This is assuming that you are using reasonable quality metals that are normally used. If you are using odd-ball, brittle, glass hard metals or something else weird then all bets are off.
 
Judging from your questions you have no clue what you're talking about.

Some of the factors that affect chamber pressure (besides the powder charge) include:
Chamber ID
Cartridge seating depth
Headspace
Cartridge case OD, wall thickness, web thickness, case length
Cartridge case throat OD, wall thickness, length from shoulder if appropriate
Bullet dimensions, including absolute diameter, circularity, base diameter, seating depth, cylindricity, base length, nose profile
Bullet dynamic characteristics, including spin axis and balance
Rifling... throat length and profile, rifling profile, diameter, and depth
... and the list goes on.

- Leigh
 
Proof Cartridges ETC.

Cartridges loaded to "Prove" Fiurearms are Specially loaded and calibrated using Pressure testing Devices ( Once Copper Crusher, now Piezo-electric pressure transducers --Direct or Strain-gauge), The cartridge load is now made with a different Powder (usually faster) than the Standard Load; also, Bullets can be of a heavier mass than the standard load, but not always.
ON Black Powder days it was simply a matter of increasing the BP load, and increasing the Bullet weight , where one was at the limit of BP in a cartridge.
IN Smokeless Powder loads, a faster Powder usually got more into the case, as efficient standard loads usually filled a rifle case anyway.

And as mentioned, NO way one can "Home Make" their own proof loads unless they have a well equipped Ballistic Laboratory ( UNiversal receiver, Tunnel, selection of test Barrels, etc, to work up the Proof load in the cartridges first, to eventually use in the subject Firearm.

"Proofing" has been with us since the Middle ages, and Formalized by the British Gun Proof Act of 1813, and by similar legislation in Belgium in the 1830s, and in France Earlier. Germany regularised its Proof Laws in 1891, although it had proofing regulations earlier than that.
THis was basically a form of Commercial protection and consumer protection. AS well, the Military of all nations demanded "proof of suitability" of all items before acceptance into Service. Military proof and Civilian (Commercial Trade )Proofing were similar in concept, but differently applied.

With the development of steels etc in the 1890s forward, The Individual proofing done in Europe was for several reasons (a) It had always been done before;(b) it really did check the structural integrity of a gun mechanism (c) in breechloading firearms, it "seated" locking surfaces in case of any minor manufacturing irregularities.

The US, with the Springfield Rifle M1903, introduced "Statistical proofing" where one rifle every 100 or so was selected at random, and subjected to various acceptance tests ( ie, accuracy, 30% OPP ( over-Pressure Proof, or "Blue Pill" cartridge) and so on. ( Read Brophy, "The US Springfield M1903 Rifle" for details). European countries continued individual acceptance proofing of all rifles ( the Germans especially).
These days, with higher standards of QA in Gun manufacture, steel composition etc, one could opine that "proof" is immaterial, at least for New Made guns...a view not shared by European nations...which have unified their proof regulations (Britain is still independant, and does not reciprocally recognise CIP ( Eu. Community) proof marking, requiring re-proof at Birmingahm Proof House before Commercial sale in Britiain.)
Re-proofing of Used firearms is required upon entry into a country in Europe and the UK...even if initially proofed in another Eu Country.( there are some exemptions under the Schengen Open Border accords in Europe).

SO, getting back to the original question...why proof? ( or make your own proof cartridges?): Personally, I think that a string of 5 or ten shots of Standard ammo should be sufficient to tell if a firearm is OK or Not, by checking the resultant shell cases etc.
( of course, done remotely, as described by many posts on many Boards.).

IN Europe, it is a simple matter to apply to the Proof House to "re-prove" your firearm (it is obligatory for all New Fireams, and in some countries, for any major repairs, such as Barrel replacement or calibre change). The trouble is ( as happend to shotgun owners in Britain,) if you send one of your Fine Purdeys to be reproofed and they find the barrels fail "Technical" proof ( "out of Proof", for wear etc) they chop the barrels before returning the gun to you....Ouch!!! if the gun, even as a collectible wallhanger, is worth several Thousands of Pounds....

SO, best stay way for an area which to the untutored, is fraught with dangers (To yourself and others). If you really need to proof test a gun ( whether new or old) have it done by a professional, although in the US these are few and far between, as the US doesn't have any National proofing Law or system...it relies on Litigious lawyers to supply the necessary "consumer protection" ( after the fact)...some Gunmakers still proof, but the majority used the Statisatical sample method, as equally valid.



REGARDS,
Doc AV
 
Cartridges loaded to "Prove" Fiurearms are Specially loaded and calibrated using Pressure testing Devices ( Once Copper Crusher, now Piezo-electric pressure transducers --Direct or Strain-gauge), The cartridge load is now made with a different Powder (usually faster) than the Standard Load; also, Bullets can be of a heavier mass than the standard load, but not always.
ON Black Powder days it was simply a matter of increasing the BP load, and increasing the Bullet weight , where one was at the limit of BP in a cartridge.
IN Smokeless Powder loads, a faster Powder usually got more into the case, as efficient standard loads usually filled a rifle case anyway.

And as mentioned, NO way one can "Home Make" their own proof loads unless they have a well equipped Ballistic Laboratory ( UNiversal receiver, Tunnel, selection of test Barrels, etc, to work up the Proof load in the cartridges first, to eventually use in the subject Firearm.

"Proofing" has been with us since the Middle ages, and Formalized by the British Gun Proof Act of 1813, and by similar legislation in Belgium in the 1830s, and in France Earlier. Germany regularised its Proof Laws in 1891, although it had proofing regulations earlier than that.
THis was basically a form of Commercial protection and consumer protection. AS well, the Military of all nations demanded "proof of suitability" of all items before acceptance into Service. Military proof and Civilian (Commercial Trade )Proofing were similar in concept, but differently applied.

With the development of steels etc in the 1890s forward, The Individual proofing done in Europe was for several reasons (a) It had always been done before;(b) it really did check the structural integrity of a gun mechanism (c) in breechloading firearms, it "seated" locking surfaces in case of any minor manufacturing irregularities.

The US, with the Springfield Rifle M1903, introduced "Statistical proofing" where one rifle every 100 or so was selected at random, and subjected to various acceptance tests ( ie, accuracy, 30% OPP ( over-Pressure Proof, or "Blue Pill" cartridge) and so on. ( Read Brophy, "The US Springfield M1903 Rifle" for details). European countries continued individual acceptance proofing of all rifles ( the Germans especially).
These days, with higher standards of QA in Gun manufacture, steel composition etc, one could opine that "proof" is immaterial, at least for New Made guns...a view not shared by European nations...which have unified their proof regulations (Britain is still independant, and does not reciprocally recognise CIP ( Eu. Community) proof marking, requiring re-proof at Birmingahm Proof House before Commercial sale in Britiain.)
Re-proofing of Used firearms is required upon entry into a country in Europe and the UK...even if initially proofed in another Eu Country.( there are some exemptions under the Schengen Open Border accords in Europe).

SO, getting back to the original question...why proof? ( or make your own proof cartridges?): Personally, I think that a string of 5 or ten shots of Standard ammo should be sufficient to tell if a firearm is OK or Not, by checking the resultant shell cases etc.
( of course, done remotely, as described by many posts on many Boards.).

IN Europe, it is a simple matter to apply to the Proof House to "re-prove" your firearm (it is obligatory for all New Fireams, and in some countries, for any major repairs, such as Barrel replacement or calibre change). The trouble is ( as happend to shotgun owners in Britain,) if you send one of your Fine Purdeys to be reproofed and they find the barrels fail "Technical" proof ( "out of Proof", for wear etc) they chop the barrels before returning the gun to you....Ouch!!! if the gun, even as a collectible wallhanger, is worth several Thousands of Pounds....

SO, best stay way for an area which to the untutored, is fraught with dangers (To yourself and others). If you really need to proof test a gun ( whether new or old) have it done by a professional, although in the US these are few and far between, as the US doesn't have any National proofing Law or system...it relies on Litigious lawyers to supply the necessary "consumer protection" ( after the fact)...some Gunmakers still proof, but the majority used the Statisatical sample method, as equally valid.



Regards
Doc AV

Dear Mr Doc AV

Thank you very much for your excellent quality information contribution.

You and Mr MG81 both suggested to test new barrels/actions with powerful commercial available loads, I think that it's the easiest, cheapest and practical way to go.

Best regards.
 
Proof Loads and Cureent practice Update:

Dear Mr Doc AV

Thank you very much for your excellent quality information contribution.

You and Mr MG81 both suggested to test new barrels/actions with powerful commercial available loads, I think that it's the easiest, cheapest and practical way to go.

Best regards.

Nowadays ( and for many years,) the major Proof Houses use what is called the "Service Proof" of firearms...the Action and Barrels are "Viewed" and several cartridges at "service pressure" ( average normal ammunition loads) are run through the gun...NO Overproof, (of any kind). If the gun shows no signs of deterioration , it is "in proof" and the Proof House markings applied. "OP" loads are reserved for brand new designs before initial sales/general manfacture to test the design and Manufacture, rather than the actual gun.

The typical British "20 tons per Square inch" is equivalent to (20x2,240 lbs per sq. inch==44,800 ponds per square inch...for a .303,( Lee Enfield or P14) that is not an "Overproof load"by any means....and the .30/06 is proofed to 24 Tper sq.in===53,760 Lbs...not a very high range at all for the .30 cal...THis is absolute pressure, NOT CUP.

Normal "Service Cartridges" ie, what one would expect in normal Service or commercial useage.

Regards,
Doc AV
 
Its a redundant question. You can not estimated load pressures. You have to measure them. That's why companies charge you money for reloading books. Firing proof loads in a gun is dangerous and it is VERY hard on firearms. If you have a legitimate reason to proof test firearms you can buy proof rounds from Remington Arms or many of the other manufacturers. I have fired hundreds over the years in controlled situations and they are nothing more than a severe handload. If you want to spend $10,000.00 I understand Fiocchi has some very novel piezoelectric pressure sensors for sale. With one of those and anther $100,000.00 you will have what it takes to build all the proof loads you care to make. To what end, I have no idea. Firing a firearm repeatedly with proof loads will destroy it and at the very least make it unsafe. Proof rounds operate at the very edge at which metal begins to move and flow. When metal begins to move and flow bad things are happening! If a gun has been proof tested, IT SHOULD NEVER BE SUBJECTED TO A PROOF TEST AGAIN. Unless absolutely necessary.

Proof loads were originally designed to test for imperfections in steel and heat treatment, not design. In this day and age there is no reason to proof test firearms. Its simply a carry over from older times and in many plants its no longer practiced.
A while back there was a company selling a reasonably-priced piezo sensor system for chamber pressures. I don't remember the name of the system though. Seems to me it was well under $1000. I remember there were some bench rest shooters that used it with pertty good results.
 
I have looked at strain gauge technology. But the people I have spoken to about it, who are supposedly in the know of such things, have always sort of laughed and said they are neat toys, and while they gave good rough low pressure estimates the technology was not to the point where it was going to replace loading manuals and reading fired cases and primers for maximum pressures. I can't start much of an argument because I have never played with them and I am just going on what other people have said. As far as creating high pressure proof loads and loads to determine the actual failure point of firearms, I do have a sneaking suspicion that there is a reason why companies make and sell pressure testing equipment that's worth more than a new car.
 
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We do our pressure testing with Kistler 6215 Pizieo-Electric gages, ballistic industry standard. They are rated for 85,000psi max. The barrels have to be drilled and tapped very precisley, or you will get bad results. 90% of our chamber pressures are taken at case mouth, the rest are mid-case. Mid-case requires drilling each case and then aligning the hole with the test port. We also take pressures at the weapons port location, this requires that the port be drilled in the center of the groove for consistant resullts and minimal fouling. We follow the Military SCAT-P test procedures for ammo, but SAAMI has there own ammo pressure test methods. They use a lot of conformal gages at mid-case. These require calibrating the brass, as the gage is in contact with the side of the case. All gages need to be calibrated before and after each test to confirm accuracy. When loading the test barrel, the ammo needs to be rolled end for end, "Frankford Roll", to distribute the powder and ensure consistant pressures. We are currently checking High Pressure Test ammo for proper values. We do this for a living and "Do it yourself" proof loads are not something to fool around with.
 
I have looked at strain gauge technology. But the people I have spoken to about it, who are supposedly in the know of such things, have always sort of laughed and said they are neat toys, and while they gave good rough low pressure estimates the technology was not to the point where it was going to replace loading manuals and reading fired cases and primers for maximum pressures. I can't start much of an argument because I have never played with them and I am just going on what other people have said. As far as creating high pressure proof loads and loads to determine the actual failure point of firearms, I do have a sneaking suspicion that there is a reason why companies make and sell pressure testing equipment that's worth more than a new car.


Hello Mr speerchucker30x3

You might like to read the attached document, it has some info on the strain gage pressure measurement method as well as other interesting information on pressure measurement.

Best Regards

- Correction -

I forgot the attachment in my previous post, and now that I am trying to attach the file, the forum file attachment manager says that I can't upload PDF files larger than 19Kb, I tried to change the file extension to JPG but the attachment manager detects the file as non image file ( smart ).

Now I am going to try to upload it to file sharing service and then I will post here the link to download.

I am very sorry for the trouble caused.


- Correction -

Here is the link to download the file that I was talking about :

http://www.wupload.com/file/2675785517/Pressure_Measurements.pdf
 
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