Test firing a barrel

[Ben Nevlezer]

I'm curious to know how anybody has test fired a barrel to ensure it's integrity. Particularly smoothbore barrels. I'm thinking an ungodly power change and a tight fitting projectile. Would like to hear how others have done this. Especially if anyone has done this without the stock and lock. I'd sure hate to ruin lock,stock, and barrel....

[Eggman]

Common practice among the patched round ball crowd (NMLRA). Most folks here at some time build a front stuffer. Common practice is to test fire the barrel before assembly - primed with fuse if flinter, or pop a cap on the barrel if percussion. Test charge is generally X2 -- a double charge of black powder; for a 50 cal this is usually around 150 grains (75 X 2). Generally behind two patched balls. The most common danger guarded against is an accidental double load. Smoothbore loads would be about the same. Extreme loads or super tight or super heavy projectiles -- never.
Never ever test using smokeless powder. Guaranteed disaster.
Footnote: Our imports (like the Pietta Smiths/Sharps, or Euroarms muskets) are test proofed at the factory -- as the proof stamps indicate.

[Don Dixon]

Lets look at the original proof standards for U.S. manufactured Civil War period arms.

The provisions of the Federal Army Ordnance Manual required that barrels of Model 1855 rifle muskets be fired twice for proof after they had passed visual inspection. The barrel was to be loaded with 280 grains of the ?best quality? musket powder topped with a 0.01 inch thick wad. This load was 4.6 times the strength of the powder charge of the regulation .58 caliber cartridge. A 500 grain bullet was to be loaded, which was topped by a second 0.01-inch-thick wad. The entire load was to be ?well rammed.? If the barrel survived first firing, it was loaded with a second proof load using a slightly reduced charge of 250 grains of musket powder; 4.16 times the standard .58 caliber cartridge charge.

The 1850 version of the Ordnance Manual required the same proofing process for smoothbore muskets, but used the standard round ball and a powder charge of 1/18th of an ounce of musket powder [385 grains} for the first charge and 1/22th of an ounce of musket powder [318 grains] for the second.

Needless to say, proof charges were not fired off of the shoulder.

Regards,
Don Dixon

[gemmer]

If it's a new barrel from a reputable manufacturer, why would you feel the need to proof it? If it's an original, proof loads would only add undo stress to a barrel that I assume you would be shooting modest loads out of. IMHO the next "regular"load after a double(or whatever)proof load with whatever you put on top of it could be the last one.

[Lou Lou Lou]

Is this one of those guns that dont have a flash hole so they aren't really guns? No manufacturers liability, it all on the consumer. Just my two cents

[Eggman]

The test would come after the touch hole (flint) or drum and nipple (percussion) were added. Remember we're talking unproofed straight from the factory barrels here.

[Kevin Tinny]

Hello, Egg:

I have had built many BP rifles from scratch using barrels from reputable makers that had breeches installed by capable gun builders. ALL were of best materials and quality and ALL were proofed by the builder with breeched bbl held in tire using 150% charge and two balls.

In two cases out of maybe 20, one in 12L14 alloy burst near the muzzle due to an invisible stress riser in a .040" thick area and one stainless shotgun bbl bulged .070" ahead of breech. The 12L14 bbl WAS proofed and my FIRST SHOT with it in finished form using normal load resulted in the muzzle burst. I felt nothing but a metallic "ringing". Lucky. The maker of the 12L14 bbl replaced it with 4140, and it's held for 20 years of competition at Friendship. The bulged SS one was initially double charged with no issues and then triple charged. We wanted to see IF 304 Sched 80 seamless DOM with .125" wall at breech would bulge instead of rupture. NONE of these were built by Bobby, Dan or Larry. The one that had muzzle rupture was 12L14 by Don Getz, cheerfully replaced, and the SS was from Sandvick tubing turned by Charlie Hunt. That was deliberately over tested to see how much it took.
Charlie's shotgun bbl's are legendary and the bulged one was HIS TEST idea.

Respectfully, Kevin

[Eggman]

Yeah in the Buckskin Report era (not sure what decade that was in) barrel steels were a hot topic. As I recall 12L14 was one of the villain's. I still have all these magazines in a pile somewhere. Bottom line, be aware of what's in your gun. I'm a HUGE proof stamp fan.

[Kevin Tinny]

Back again, Egg:

Was involved in the review of those reports that contained flaws.

The issue began with 7/8" octagon 54 cal bbls in 12L14, Ledloy, LaSalle Stressproof and "Mach V" alloys. The issue was THIN WALLS, much less the alloy. 12L14 has been fine in correct wall thickness BP bbl's for years.
The likes of Bobby, Dan and Larry's 12L14 bbl's have been fine, esp for cast bullets with only safe BP loads. I use many 12L14's with no concerns.

Smiles,
Kevin

[Eggman]

INTERESTING! I don't have any recollection of anyone going to bat for those steels (12L14 and Stressproof). Side note - my two Kentucky flinters - my project fun gun a Japanese mfg kit from Dixie Gun Works with certified barrel; my custom long rife built by Dave Ferguson with Douglas barrel.

[Ben Nevlezer]

Great conversation. Thanks guys.
My reason for asking is I have an original '42 smoothbore barrel that took a lot of polishing to bring back to life and I want to make sure it is still safe to shoot and I really don't want to risk destroying my stock and lock. I'm thinking hose clamping it to a 2X4 with a screw through the tang then putting the breech end inside a tire with the muzzle end laying on the tire then setting another tire on top of it to hold it down. Double charge with 2 balls and ignite with cannon fuze. If nothing else it may result in an impressive explosion.
I will add that it is a shortened barrel so that should reduce it pressure somewhat.

[Eggman]

Well after all that back to the '42. My only concern with this gun would be the nipple threads. Unless you see a visible fault or crack somewhere MY inclination would be to trust it. Part of my trust is based on my usual light charges of 55 grains BP. Refer to Don's comments on how well these guns were built.
(Final comment -- about 90% of your pressure curve is during the first 3" of ball travel).

[Ben Nevlezer]

Well after all that back to the '42. My only concern with this gun would be the nipple threads. Unless you see a visible fault or crack somewhere MY inclination would be to trust it. Part of my trust is based on my usual light charges of 55 grains BP. Refer to Don's comments on how well these guns were built.
(Final comment -- about 90% of your pressure curve is during the first 3" of ball travel).
I'm in agreement Eggs. But I do want to be sure. Besides, what's the worst that could happen? A catastrophic explosion that didn't get caught on video? If it blows, I promise it will take my IPad with it.
Anybody know how to retrieve video from an exploded iPad???

[John Holland]

Ben - Do you know that your original Model 1842 barrel has a seam? That barrel was made by wrapping a flat sheet of soft Iron around a mandrel, and then hammer welded shut. I highly recommend you do not overload a hammer welded barrel that is no less than 165 years old, because they are known to burst at the seam.

[Ben Nevlezer]

Ben - Do you know that your original Model 1842 barrel has a seam? That barrel was made by wrapping a flat sheet of soft Iron around a mandrel, and then hammer welded shut. I highly recommend you do not overload a hammer welded barrel that is no less than 165 years old, because they are known to burst at the seam.
Thanks for the advice John. I will definitely keep that in mind.