barrels

[mike fisher]

Hi, I would like to ask why a traditional barrel have ticker walls using bp and a modern cartridge shotgun barrels have thin walls?Thanks Mike.

[Roger Fisher]

Soft expandable iron/Strong modern steel!!!

[E.vonAschwege]

I've found a lot of original rifles to follow that rule, but fowlers and pistols no.  The thinnest "production" fowler barrel is probably Caywood's 41" barrel or Colerain's 46" 16g barrel (3.7lbs).  These still have 3/32 to 1/8" barrel sections at the muzzle.  Original fowlers, intended only for shot, have barrel walls around 1/16" or less.  Smoothbore pistol barrels are the same way.  Some of the finer guns at the Metropolitan Museum have barrel walls that looked close to 1/32", THIN!  I imagine part of this is for liability reasons today.  Getz and the other custom guys will make them I'm told.  Don, want to chime in?

-Eric

Oh, woops, I just realized you were comparing to thin modern shotgun barrels... I've wondered myself why a lot of modern BP barrels are still so much heavier than contemporary rifle and shotgun barrels.  A lot of barrels are made of 12L14, very easy to mill.  Modern cartridge barrels I imagine don't mill as easily.  Just a guess...

[flintriflesmith]

Hi, I would like to ask why a traditional barrel have ticker walls using bp and a modern cartridge shotgun barrels have thin walls?Thanks Mike.

I'm not sure what you mean by "traditional" but original 18th and 19th century barrels on muzzleloading shotguns/fowlers are usually much thinner than smokeless powder barrels. The originals have some mass at the breech but taper fairly quickly and are really thin toward the muzzle. Modern repro barrels I have seen do not match the originals.

I once owned a French fowler with a 46 inch barrel and the entire gun weighed under five pounds!

Gary

[Acer Saccharum]

One reason I suspect modern smoothbore M/L barrels are thick at the muzzle is because of ..... liability. It's also a more difficult job to turn a barrel thin at the muzzle. Takes more time and care.

Smokeless barrels are a different animal altogether. Shotguns have lower breech pressures than rifles, hence thinner walls.

[timM]

I have been made to understand that black powder is an explosive, so possibly the peak pressures at the breach?  ie.  some original barrels with a thick breach and then a transition to a relatively thin tube being possible?  

The contrast of smokeless powder being a propellant with various longer burning rates that modern steels can safely encompass? The few Damascus barrels that I have seen blown up, damage was forward of the breach but not so much forward like a typical bore obstruction?  Could this be a characteristic of smokeless powders longer burning rates?   A couple of unqualified thoughts.  tim

[Jerry V Lape]

Makers of traditional rifles lacked the sophisticated pressure sensing and materials testing available to current makers.

Current makers have advantage of advanced metalurgy, heat treating and barrel making methods. 

Traditional rifles have thicker barrels than traditional shotgun barrels. 

Current makers know the pressures to which they are building because of either SAAMI or CIP standards whereas the tradtional makers only had the crudest of proofing systems.  They also know what the maximum pressures will be at any particular point along the barrel and can adjust thickness accordingly. 

Breeching systems are better in modern firearms. 

Some modern shotgun barrels have passed proof testing in Europe with wall thicknesses of less than .020 of an inch but that thickness wasn't near the breech. 

[mike fisher]

Hi again, Thanks for replays, I just want to have a better grasp: while a flintlock is having some thick waled barrel using bp, a modern shotgun can shoot a deer slug with smokeless powder from a thin waled barrel. Thank and have a good weekend, Mike.

[Z. Buck]

ok it seems to be not an uncommon practice to breach modern shotgun barrels for use as a muzzleloader, but what of the explosive vs propellant argument, does this suggest that it is not a good idea to turn a smokeless barrel into a smoothbore that has any possibility of being used with ball? maybe im missing something, but it almost seems like we are saying we have to make BP barrels thicker because it takes more abuse, but we all know you cant shoot smokeless because the pressure is different, but is the pressure with smokeless higher or just a sharper curve? i suspect beyond just legal liability perhaps modern made BP barrels are thicker to take more abuse from ramrods and such (of course this is just accounting for what is perhaps another liability issue, and purely speculation) if i am wrong in any of my assumptions please set me right, i cant learn from being wrong if no one informs me that i am

[Jerry V Lape]

Blackpowder, when loaded properly, meaning with the projectile seated on the powder, does not act as an explosive but burns progressively.  Smokeless and Blackpowder pressure/time curves are very much the same except early in the burn smokeless usually produces an extreme pressure spike for a very short time which black doesn't.This spike occurs while the load is within the chamber area.    Blackpowder cartridge expert loaders, who know what they are doing, routinely shoot  safe smokeless for black loads and produce ballistics matching blackpowder pressures.  Muzzleloaders with their screwed in breech, barrels of weaker metals and open systems (touchholes and percussion nipples) must not be so loaded.  Modern shotgun barrels, safely breeched, will handle blackpowder pressures because they are stronger in the correct areas to deal with the spike from smokeless. 

[Doug Cline]

Mike, One thing to remember about cartridge guns, the cartridge is also helping to contain and control the pressures, and in a sense increases the barrel thickness at the breech. A modern shotgun shooting slugs is not as thinwalled at the breech as it appears; if you add the thickness of the shotshell, the barrel, and if it's a pump or semi-auto the receiver around the barrel. As Eric and Gary pointed out many original guns had as thin or thinner barrel walls than what is currently produced.

[fm tim]

Used to shoot black powder loaded into shotgun shells as a joke during skeet matches.

We snuck them into shooters cartridge pockets.

Funny noise, lots of smoke, surprised shooter, no ill effects.

[J.D.]

I did that once, and only once. However the shot was also replaced with feathers. The shooter was not amused. He also took exception to those who saw the humor.

Some people take shooting so seriously. I thought it's supposed to be fun. 

As mentioned, modern barrels are made of much higher quality steels, than originals. A few ML barrel makers go to the extreme of using 4140 steel, which is used for modern, high power rifle barrels, but most use low carbon, free machining steels that will contain BP pressures much better than original wrought iron barrels.

[doug]

     I think most of those replying have missed the main point; rifles operate at higher pressures.  A 12 guage shotgun with 3 drahms of black powder operates around 4000 - 5000 psi as near as I can make out from Lyman's Manual.  Even a modern shotgun operates around 11,00 - 12,000 if memory serves correct.  Both old and new have a breach thickness of about .15" although some french and german guns are thinner.  Muzzle thickness runs from an absolute minimum of .016" to a more common of .025 - .030" because the pressure has dropped substantially after the first 10"/

      Rifle pressures run considerably higher and with hot bp loads I think can run 20,000 - 25,000 psi.  Their wall thickness at the breach for a .50 cal as an example would be roughly .25" or almost double the shotgun breach.  The thickness at the muzzle is probably based on tradition rather than need and I have european rifles with muzzles than at a guess are around .1" thick

cheers Doug

[mike fisher]

Impressive response, thanks again, Mike.

[Stophel]

I have an early 18th c. German fowling gun.  About .50 cal.  Weighs about six pounds.  The barrel is swamped, and the muzzle is just about 3/4", and the narrowest part of the barrel is just under 3/4".  Pretty light.  Breech isn't huge...about an inch and a sixteenth, I think.

[LynnC]

Original fowler barrels do seem to be a lot slimmer / lighter than what is available today.

Must be a very quick taper at the breech and a long taper in the chase to get such slim lightweight barrels.