proofing a barrel

[flashpanner]

any thoughts on proofing a barrel? Is the purpose to check the integrity of the breech plug and barrel or to check to be sure that the barrel assembly does not divorce itself from it's wooden frame holder? What is the usuall proceedure (ie, powder charge size # of balls, etc) Ideas are appreciated.

 

[Wes/Tex]

The usual rule-of-thumb is double charge and double ball. This is suppose to determine that the barrel and breech plug are properly tempered and assembled. Having said that, I'll add that if your rifle is of modern manufacture by a reputable maker then proof testing shouldn't be necessary. Modern liability laws usuall assure things are done up to snuff.

For information on amounts, etc., DWG's catalog has a long list of standard and definitive proof charges from the Liege proof house. If you've got the money, tie your gun to a tire, fill her up like they report and hank a LONG string from behind cover. If it doesn't turn into a daisy, it's passed the proof test. Even then, you may have caused such internal damage that it may go KAPOW! with the next standard hunting round you load. Nice to know about proofing but be real cautious about trying it out unless you've got other guns to shoot!! Good luck. :m2c:

 

Proof testing as said can cause unseen damage that may come back to haunt you. Why stress a gun with a load you will never shoot in the first place.
I proof test by loading a normal charge with patch and ball I would normaly shoot. Prime the pan.
Aim it at a target, squeeze the triger and it it goes BOOM
and smoke flys, that's proof enough for me it shoots.

Woody

 

normal load ?
proof the barrel , i know i have for a fact shot 160 grains of 3F with a patched RB from one of my rifles . i don

 

[uncrichie]

I am also interested in this topic. I'll be building one soon and am unsure how to go about this as in how many patched round balls (if actually more than one) and how much powder. I have however made a plan to take precise breech measurements of the barrel (before and after) with a micrometer. I think this will at least tell me if there is any swelling to the breech area? At least that is the plan. I certainly will research the ball and powder issue before proofing day. Uncrichie...

 

[FireMaker]

The idea of a double load with double ball gives you a lot of faith in your barrel. The man that built my swivel piece proofed with 400 gr 4f and 2 balls while normal charge is 200 3f and 1 ball (1 inch bore). When doing public demos I have a great deal of faith in the piece.

 

[roundball]

The idea of a double load with double ball gives you a lot of faith in your barrel. The man that built my swivel piece proofed with 400 gr 4f and 2 balls while normal charge is 200 3f and 1 ball (1 inch bore). When doing public demos I have a great deal of faith in the piece.

I've always wondered about something using "proof loads though...how does anyone know if the proof load didn't in fact stress the barrel to the edge of a breaking point and now it's a ticking time bomb on the verge of "letting go"?

 

[FireMaker]

A number of cannon sites discuss use of exray and magnaflux?(I think that is the word) to do stress checks. They also use hydra pressure for stress tests. These are done after the proof.

 

Hey folks, I am a bit confused here. maybe I missed something, but I thought that all barrels in all firearms (ML or not) are proofed at the factory? When building a rifle from a kit or jsut parts should not the barrels already be proofed by the maker and not the builder?

 

[Gary]

Barrel bought for kits or those coming from kits are generally not proofed. How can they? No breechplug fitted and no touch hole drilled or nipple installed. Now, if the kit is one of those "final assembly required" jobs, it's likely to be proofed.

 

[Musketeer]

I've read that the U.S. does not have any hard and fast guidelines concerning the "proofing" of a blackpowder muzzleloading barrel. I would think that a large scale U.S. maker like Lyman would proof their guns, though I don't know for sure. Many of the smaller makers/importers like Military Heritage, MVTC, and Loyalist leave the responsibility of proofing to the buyer. Military Heritage doesn't even drill the touch holes on their guns, though MVTC does, and Loyalist will at the buyer's request. Pete at MVTC claims, however, that the guns he carries (Indian-made) regularly pass the strict proofing tests in countries like England and Germany that have national proof houses, and I have no reason to doubt him. I just proofed my pistol I got from them with double powder and two balls, and it's fine. :thumbsup:

 

[kentucky bucky]

I just proofed an old ML shotgun barrel from a gun that I fitted with new L&R back action locks. The gun and barrel is in great shape, but the locks that were on it were pitiful. It has Belgium proofs and the brazing holding the barrels together is in fine shape (rings like a bell). I wanted to make sure that if I had cranial/rectal inversion, and loaded two loads of powder in a barrel, that it could take it. I proofed it with a double helping of shot and 2f, using the cannon fuse method with the barrel out of the stock and strapped to an old tire with bungee cords, so it couldn't bust the stock. It makes sense to me.

 

Aaaah!

The once a month discussion of proof testing.

If you check the archives you will discover that the consnsis of last time was that if you did not have the proper equipment (X-ray/magnaflux) to examine the possible damage done by the proof test itself you had wasted your time.

All you proved was that the gun did not blow up "this time"!

There are no standards and there is no one to sue and no one will replace the parts you blow up, taking into consideration that anyone can blow up anything if they try hard enough.

Also take into consideration that some of the firms like dixie and Getz have done extensive "blow up testiong" on their own in order to make company decisions.

Ever wonder why they do not offer 3/4 across the flats .50 barrels?. It is not because a double charge of powder will blow the tube. It's becasue a well over double charge will blow a hole through the dovetails made for the barrel lugs and sights, if you plug both ends of the barrel with a breechplug before the discharge!

You can pretty much assume that your Green mountain barrel is safe with any "normal mistake" you will be making during the loading process.

I just would not advise "short starting" them too often.

That is the one mistake that scares even the barrel makers. They will usually hold together the first couple of times, but repeated short starting will eventually fatigue the barrel steel at the short start point and rupture.

 

[tg]

This practice is a throw back to the time barrles were made by hand with a single weld om the bottom or a spiral weld around a mandrel, probably quite important to test the welds on each barrel then, not with the type of material and technology used now on barrel making.

 

[Gary]

BTW, considering the metallurgy and manufacturing techniques of today and if used "reasonably" with blackpowder, I wouldn't worry too much about it. It's the older Damascus barrels or the single weld barrels made of steel or iron of unknown quality that would worry me. Old is nice, but our metallurgy is superior.

 

The last I heard about the horrific breeching on the Indian Made Sea Service Musket I returned to Mil Heritage, was that they were going to proof it with 200gr. 2F and two balls. I'd expect this would be without patchs, so the pressure built might meet a heavy 'normal' load of 120gr. and 1 ball.
: They told me they'd keep me abridged on the 'test' results - I haven't heard from them since they told me they'd received the musket and given it to the gunsmith who'd do the test. I really didn't thing they'd contact me to tell me it had blown or leaked - at least not truthfully. The two gunsmiths I showed it to were horrified and one knows very little about BP or the guns- the other is one of the finiest muzzleloader makers in North Americal.
: In case you've forgotten, the musket was poorly breeched, with only 4 threads attempting to seal the powder gasses in. The other threads engaged, but did nothing to seal the plug. The engaging threads themselves did little to seal the plug as fouling built up in the trough between the threads and the 'flash-plate' of the plug. A 1/10" thick washer of steel, 1.1" in dia. is all that held the gasses from leaking out the sides of the flash plate. Instead of having .070" engagement each, they had .002", .011", .014" and .022", so were very sloppy. It was only the plate against the end of the barrel that actually sealed the breech.
: Note the groove between the last thread (which didn't engage by the way)and the flash plate- there was no reason for cutting this gouge out as the threads could have been cut right to the plate. If they had been made properly, perhaps the threads might have kept the fouling in check as they do on all other normal compercial guns.
: Mil Heritge states that at $500.00 US,($750.00CDN) you cannot expect good machining. Well, perhaps not at $500.00 US, but at $369.95 you can. Your GPR's have proper machining on the plugs & that's a promise. I mean, even I can make proper threads on plugs and barrels and make them fit without gaps of .187" length between the plug end and bore.
: Sorry if I got carried away.
:

:

 

[robinghewitt]

how does anyone know if the proof load didn't in fact stress the barrel to the edge of a breaking point and now it's a ticking time bomb on the verge of "letting go"?

I think the Proof house measures the bore 9" in front of the breech before and after the shot. If it increases by a calibre then it failed. Something like that anyway.

 

[robinghewitt]

You can send a barrel for proof without a breech plug fitted and they will put one in. However, you would incur a hutting charge.

It is kinda hard to understand why the US of A doesn't have proof laws. If there had been US proof laws back in the olden days I think we would now have lots of fine antique American shotguns rather than a zillion Belgian klunkers
:imo:

 

I'll agree with that one for sure. Having the cheaply & poorly made Belgium guns fail proof, would have prompted local US gun makes to make many more for the market- perhaps? In the 1820's to 1850's quality double & single smoothbores were much sought after in the Western US. There were very popular for buffalo running. Even W.Greener had a distributor in San Fransisco, and complained bitterly of the Belgium name fakery, lack of quaility & and lack of having to prove safety.(gun proofing)