Question on barrel wall thickness for smoothbores

[Artificer]

Folks, I've seen some original civilian smoothbore fowler and pistol barrels that I have to admit downright scared me how thin they were.   Maybe it is because I'm much more used to military guns of the early to late 18th century period.

After seeing that gorgeous small Queen Anne pistol I mentioned in the "re-convert or not" post I wrote, I'm thinking I'd like to make a reproduction of it.  I doubt I will ever fire it in competition, but I want it safe to fire and I plan on firing it.

Is there a formula on how thick a barrel wall thickness should be on a smoothbore pistol to ensure the pistol is safe to fire and yet thin enough it won't be like a club?

Thank you

[jerrywh]

What kind of steel?

[Artificer]

Jerry,

Thank you for the reply.  Your question is more than valid because I didn't explain fully.  My apology.  Just realized that was a "Duh" moment for me.

To be honest, I'm not sure.  What I should have written is my intention was to have one of the real muzzle loading barrel makers make it out of an appropriate steel on a custom order - if one would accept the commission.  I don't know enough about muzzleloading barrel steels to make that decision and wanted to leave it up to someone who does know. 

Maybe the best thing would be if I measured the original barrel and then a real muzzleloading barrel maker could recommend the appropriate wall thickness from the steels they use?

[Don Getz]

Art........If you study this type of pistol, you will find that most of them have an octagon to round barrel, are many times
a rather large bore, and are smoothbores.   Many of these have a rather thin wall out toward the muzzle.  We do not have a formula for wall thickness, however, in a pistol like this the loads would be rather low, and resulting pressures would be the same.  When you said you would never shoot it in competition, this type of pistol was never meant for that,
it is a close range, point and shoot type of pistol...........Don

[Mike Brooks]

Breech or muzzle thickness?

[Artificer]

Art........If you study this type of pistol, you will find that most of them have an octagon to round barrel, are many times
a rather large bore, and are smoothbores.   Many of these have a rather thin wall out toward the muzzle.  We do not have a formula for wall thickness, however, in a pistol like this the loads would be rather low, and resulting pressures would be the same.  When you said you would never shoot it in competition, this type of pistol was never meant for that,
it is a close range, point and shoot type of pistol...........Don

Thanks for the reply, Don.

You make an excellent point about most of these pistols being octagon to round.  I'll have to take a closer look at the pistol and see if that is indeed what it is, though I'm pretty sure it was full round and tapered. 

I fully realize this is a period "belly gun" or at most an "across the table or room pistol" for point and shoot and that's why I mentioned I wouldn't shoot it for competition.   I'd still want to shoot it at a man sized silhouette target to get the feel for shooting it and with a load that would be authentic for the intended use of the pistol.  Yeah, I realize that is kind of strange.  I'm the kind of guy who went out and shot 40 rounds from a 2 Band, Pattern 1858 Enfield Rifle with full issue type loads, in about 2 1/2 hours to see what it would have been like in combat.  Never did it again as my shoulder was sore for three days, but I now know what it was actually like. 

I've carried one of the triangular shaped bore size check tools in my wallet for years and of course one of the few times I would have liked to have had it handy, I didn't have it in my new wallet.  The next time I check it, I'll make sure I have a set of precision dial calipers with me and I can at least give a barrel wall thickness at the muzzle in the original pistol and some other measurements of course.     

[Artificer]

Mike,

Thanks for the reply.  I realize the breech thickness is the most important to safety, but the muzzle thickness is what I've seen in some original guns that were so thin I personally would never have fired them - even had I been around when they were new.

[Mike Brooks]

Don't worry about the muzzle, it can be paper thin and be fine, I have several antique shotguns with exceptionally thin muzzles and they are fine. It's the breech that counts.

[Artificer]

Don't worry about the muzzle, it can be paper thin and be fine, I have several antique shotguns with exceptionally thin muzzles and they are fine. It's the breech that counts.

Well, that must be true as some of the original fowler barrels I've seen were almost paper thin.  Thanks for the reply.

[James Rogers]

As far as the long guns go...Fowling guns that had thin muzzles were intended for shot. Many were larger than actual bore size inside the muzzle end. Some fuzees had a thicker muzzle wall intended for delivering ball. Most of the "fowler" barrels available today are more comparable to fusil thickness.

[Dan'l 1946]

And that is a significant point. The difference between the true fowler barrel and a fusil barrel is huge. Folks who complain that their new fowler doesn't feel lively or that it swings slowly usually never realise that they have a heavier fusil barrel and not a nice and light fowler barrel.  Fusil barrels are easy to come by, fowler barrels not so much.

[Artificer]

Capt Jas and Goex4g

Thank you for adding that information, that is indeed interesting and explains another reason why early fowlers I've seen had such paper thin barrels. 

The only time I've ever used shotgun shot was in my Navy Arms Brown Bess carbine that I used in the Northwest Trade Gun matches years ago in the late 70's. 

I never really examined the shotguns they used in International Muzzleloading Competition that much as to how thick the barrel walls were at the muzzle.  They used both originals and repros with the Mortimer Repro's being very common in the repro categories.  I could be mistaken in my memory, but I seem to remember the Mortimers had thicker barrels than the early fowlers.  Most of the original guns they used were single barrels and the flintlocks were from 1810 or later.  I don't remember even those originals having such paper thin barrels, but again, I can't say I actually looked at them that hard for barrel wall thickness.  Of course, those guns had somewhat shorter barrels than many of the early fowlers as well.  A shorter but slightly thicker barrel would have swung OK, or they just got used to shooting the guns they way they were. 

[chiefs50]

I wouldn't worry about the thinness at the muzzle.  I have a Contender pistol in .45 Colt.  It has an octagon barrel and is extremely thin at the muzzle.  It's never been a problem and I shoot some fairly stiff loads in it.

Mike

[northwoodsdave]

I have two antique fowlers and a French musket.  All have thinner metal at the muzzle than usually seen in modern black powder.  They are also lighter, and thus easier to handle compared to their modern counterparts.

The musket is heavier at the muzzle, but still nothing like a modern fusil barrel. It was also modified (probably around the Franco-Prussian war in 1871) to a breechloader.  These guns were subsequently cut down and surplussed out, so the barrel is likely shorter (and thus less thin at the muzzle) than the original.

I have to wonder if there was a bit less concern about liability back then and, perhaps, simply an acceptance that the occasional barrel exploding was to be expected?  This would especially be true in pistols, since the Saturday Night Special was also available in black powder days.  The gambler's "last ditch" pistols I've seen out West often seemed as potentially dangerous to the shooter as the intended victims!

Dave

[Dan'l 1946]

I wouldn't worry about the thinness at the muzzle.  I have a Contender pistol in .45 Colt.  It has an octagon barrel and is extremely thin at the muzzle.  It's never been a problem and I shoot some fairly stiff loads in it.

Mike

The Contender is a breechloading cartridge pistol and the steels used aren't the same.  And those breechloaders are a bad idea that will never catch on anyway...

[Dan'l 1946]

Artificer-most of the parts sets offered by the bigger muzzleloading suppliers come with fusil barrels. The same profile is used for 28 gauge to 20 gauge. That's why you see some eight pound + 28 gauge fowlers out there.

Years ago, a friend and myself ordered fowler part sets from the same source. Mine was a 16 bore and ended up weighing just under seven pounds--still a trifle heavy, but his 28 bore weighed a full 1 and 1/4 pounds more and the barrels when laid side by side were identical in profile. You won't have this problem with the higher price kits.

[Artificer]

Goex,

I can easily see how a 28 bore gun with a 20 bore outer profile would be way too heavy.  Good info.  Thanks.

Regards, Gus

[frogwalking]

When I was a teenager, back in the 60s, I had a 14 gauge flint fowler I bought from Turner Kirkland.  The barrel was thin.  Even worse, it was not tapered, so it was thin all the way.  Being a young man, I thought I was immortal.  We loaded that thing as if it were half an inch thick.  I was once in the woods, looking for squirels, saw a deer.  Of course, I loaded a round ball on top of the shot and stalked the deer for half an hour.  I lost him.  Grimmaced, held on tight and shot the thing.  The fact that I am still here is evidence for the strength of that thin pipe.  I later burned my eye with they thing, but that was not the gun'f fault.