proof testing

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moharrow

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I have heard many contrary opinions on the safety of Indian gun barrels.
so I have begun an experiment.
I will be testing a number of gun barrels from several different suppliers.
here is the method we have followed so far,
Under controlled conditions in the shop,the temp of the barrel is recorded and then they are measured at several locations on the barrel with a micrometer. then the barrels are taken to the range, loaded with a triple charge of the recommended load. and 2 round balls of the correct size for the barrel being tested. The charge is then electrically ignited from a distance of 50 feet from behind a berm.
The barrels are then returned to the shop. cleaned completely. cooled to the same temperature as before the test . remeasured. then the breech plugs are removed and the bore is inspected.
So far the barrels that we have checked were obtained from loyalist arms and middelsex trading village. no failures so far also no measurable deformation. we have managed to destroy one test stand. we will be testing barrels from other suppliers as we get them
I would welcome any suggestions anyone has on how to improve our procedure .
 
The mud slinging is why I am doing this. I have heard many posters say how dangerous these barrels are but no one has offered anything other than their opinion. no hard data. so I decided to find out if there is any truth to this and hopefully provide some facts. so that those who are interested in these arms can get real data on their safety
 
I want one of the middlesex blunderbusses. I don't know why, but I've always wanted a 'buss.
 
well you will be glad to know that the middlesex barrel not only passed but its the one that broke the test stand
we are designing a more robust stand for the next series
 
Proof testing of individual specimens provides evidence that a particular design meets a certain specification, but no more. Confidence in the population requires large numbers of such tests be conducted - how many depends on the size of the population and the level of confidence desired.
 
and that is the reason we are testing a wide variety of barrels from multiple suppliers. for example we will be testing 20+ doglock pistol barrels from loyalist arms alone. we have already tested the first 6 with no failures or deformation.

we have also attempted to test one loyalist blunderbuss barrel to destruction. we loaded 850 gr 2f goex powder and 3 .735 round balls.
the blast was impressive. but the only thing that failed was the test stand. the only noticeable change on the barrel was that the touch hole suffered some minor erosion
I will be providing more detailed test results and video in the coming weeks as both time and finances allow. this is proving to be a somewhat costly research project
 
Jaymo said:
I want one of the middlesex blunderbusses. I don't know why, but I've always wanted a 'buss.
Click to expand...
I was just talking about the Blunderbuss and I,ve wanted one ever since I've seen one,and-- I know why YoU want one ! probably for the same reason I want one ! They can shoot just about anything you can fit in the barrel :evil: and they probably kick like a mule :D
 
While it's an excellent effort..., the problem that you have is the arbitrary load that you are using (at least it seems arbitrary - no offense meant). You might want to contact the Birmingham Proof House in England, and ask them what they would base a proof load upon. I think the BP proof loads are only 160% of the "maximum" user load, so you may be exceeding the proof load (which is great if the barrels still hold), but if you have some barrel failures in the future..., and you are exceeding the proof load, you have only demonstrated that exceeding the proof load is "bad".

If I had the money I'd send you some already proofed barrels from recognized proof houses, so that you could then compare the proofed "safer" barrels with the ones you are testing by using your same loads, and we'd see how those barrels stack up to your current test subjects.

AND..., again, thanks for the effort.

LD
 
I am currently contacting the birmingham proof house as well as attempting to contact the proof house in liege france and looking for contact info for the proof houses in italy and spain. it is my hope that there is some sort of international standard that we can test to.
thanks for the input. hopefully we can put to rest many concerns this way
 
There are recognized standards for this in Europe and Great Britain. I once looked them up on the internet without contacting any proof house. (the details are foggy now.) The proof house would of course be a more authoritive source if you can get any info from them. I'd second the notion to do it like the proof house does it.

The reason I looked this stuff up was that a certain party I shall not name made a lot of noise about this issue. Looking at some modern manufactured BP firearms from Europe I found the pressures marked on the barrels were astonishingly and unbelivably low. I still don't have an answer for the marked numbers.
 
Unfortunately, I have been told that although the proof houses have standardized pressures for modern cartridges, and specific loads to test barrels intended for those cartridges..., when it comes to muzzleloading barrels, there is no absolute testing standard, which is one of the problems with trusting muzzleloading proof testing. I could, of course, be misinformed.

When one looks at loading data for Hodgdon Triple 7 going into what were originally black powder cartridges, you do get some idea as to the lower pressures for the original propellant. So from the Hodgdon Basic Reloader's Manual 2006 p.40 :

.38-40.......30 grains.........8,400 CUP
.44-40.......35 grains.........9,900 CUP
.45 Colt......37 grains.......13,500 CUP

The Triple Seven Load, for example, is only 500 CUP below the 14,000 CUP pressure of the max load for the .45 Colt using smokeless powder listed on p. 31. So the reloading manual does indeed take into account that a person may be shooting freshly made reloads in an antique gun.

and by contrast,

9mm................(p. 29).......max smokeless pressure 33,800 CUP
.38 Special +P...(p. 30).......max smokeless pressure 19,800 CUP
.40 S&W............(p.30).......max smokeless pressure 33,600 CUP

Now these are of course not approaching a proof pressure load, but if it was as simple as multiplying the Triple 7 load of thirty grains in the .38-40 by four, to get 120 grains as a max load for a .38 caliber, muzzleloading rifle, and simply multiplying the max pressure in the same way, one would get 33,600 CUP, which is still behind the max for a 9mm pistol.

Extremely simplistic, and inaccurate, but does give a clue at the low pressures required to hold a black powder barrel together and why it's so easy to blow up a proofed black powder barrel, or even an American made black powder barrel, when the user has a barrel obstruction or uses smokeless powder

(There is waaaay more physics involved, the volume of the chamber and the weight of the proof projectiles, as well as the granulation of the black powder used in the test - this is just a crude illustration).

LD
 
I have recieved an email from the Birmingham proof house informing me that they are sending me an information packet.
also the gentleman I spoke to on the phone there stated that the general proof load for a muzzle loader is 250% of a normal charge with a double weight projectile. He said I would recieve more detailed information in the packet.
Also he mentioned there is an international standard.The United Kingdom is a member of the International Proof Commission ( the CIP), the United Kingdom recognises all the proof marks of other member nations and reciprocally they all recognise United Kingdom marks.
 
on revolvers, still reaserching that one, I am hoping there is something in the information packet from birmingham on that
 
An excellent effort, and my heartfelt thanks. It takes a great deal of personal time and money to do such a thorough job. I am wondering how they determine the max load..., out of curiosity not to be critical. There is probably some formula based on the volume of the breech area or something like that.

I wonder if they take into account the quality of the BP used? I mean a Bess barrel proofed in say 1812 and greased up and stored, if it was found to be visually sound, would it pass proof in 2013? Perhaps they have a cut-off date where they recommend a barrel older than that date be reproofed?

Looking forward to your results. :D

LD
 
Suggest you magnafluxed the barrels after proofing them too.
 
on magnafluxing, that is already in the planning stages.
and on maximum proof loads this is what I have found so far

for Great Britan- 250% powder load and a double weight projectile. 100% of all barrels must be proofed

for France- 225% powder load and a double wight projectile, no mention of what percentage must be proofed

for Belgum- 225% powder load and a double wight projectile, 100% must be proofed

for Spain- 200% powder load and single projectile, a represenative sample must be proofed ( no definition of what representative means)

for Italy- 140% of reccomended load single weight projectile, 100% must be proofed

also those countrys that require 100% proofing they have some severe penaltys for sellling unproofed barrels

also all the countrys listed are members of CIP and honor each others proof marks
 
I just want to add my thanks to you and your crew for taking on a job of this nature.

It's impressive that your early triple powder/double ball loads were found to be apparently tolerated by the barrels. The fact that you were not able to detect any noticable distortion points to the metal staying within its elastic tolerance.

As someone that likes their C&B revolvers I'm eagerly awaiting the information on how they proof test those when the volume for the load is so limited.

Oh, that was a nice touch doing the video dressed in the period costume.... :D

On the magnifluxing I suspect you'll find that it's largely given way to magnetic resonance testing. They ran a MR test on on my aluminium scuba tank the last time I had it in for a visual inspection and prior to sending it off for a hydro. The idea being that it could catch micro fractures before exposing it to the serious pressure of a hydro test.

You might want to contact a few scuba shops in your area to see if they have a MR tester and arrange some sort of money or time exchage for checking the barrels.
 
I am Very Glad to see this type of testing going on with the Indian made pieces. If sufficient numbers are tested, I would be very happy to see a cheap repo available on the market.


There are only two improvements that I would suggest: as Mykeal suggested, enough examples of the same models that a representative level of quality is acheived. Second is the test samples be acquired randomly and blindly without the supplier knowing that you intend to proof the barrels to prevent the cherry picking of your test subjects.
 
well here are pics of the new test stand
006.jpg

005.jpg

that it so far, should have it finished tomorrow. and off to the range monday with more barrels
 
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