Simple breechloader designs?

[Victor3]

 I've been hit with the breechloader bug...

 I'm trying to come up with a simple, safe and practical design that can be very easily made. What do y'all think of this one?



(Sorry for the crude napkin sketch - my CAD software isn't working at the moment and it's been a while since I scratched one out with a pencil)

 The threaded plug at the rear as well as the bbl would be pinned and welded into the breech sleeve.

 Any thoughts about this or other designs would be most welcome. Again, I'm looking for SIMPLE designs that can be manufactured easily by the hobby-machinist with a mill, lathe and welder - Interrupted-triple-lead-buttress-threaded-cam-locking designs are a bit too complicated to make for most of us...

 

[KABAR2]

The main thing with doing any breech loading design is not
running afoul of Federal laws and unintentionally creating a
an unregistered Destructive Devise.It must be of a pre 1898 pattern,
and even some of the late ones are forbidden.
If you work from a known
pattern that was built in the 1860's you should be alright.
I am not a lawyer nor do I play one on TV...... the operative
word there is should. test what you plan in model form
50 caliber or below. write the ATF tecnical branch sending
photos of what you built and ask if built in a larger form
would they class it as a DD. this course of action would
keep you from being a Grey bar guest.

[Cat Whisperer]

Goood legal advise - if you have written permission from ATF you're off to a good start.

Breech loading is problematic from the combined issues of strength, simplicity and having to seal (and cleanup).

Threads reduce the strength by %50 or so right off the bat.

Welding brings in the issues of quality/strength/hard-spots/porosity/type-of-materials and others.

I have a .50 cal cannon, 3" od at the breech with about a 1" plug that threads in and has a copper disk that seals against a seat at the breech of the bore with a crush-fit.  Not designed to be taken apart often.

The 155mm Self-propelled cannon has a stainless steel and neoprene mechanism for sealing - the pressure pushes back on a stainless bowl shaped piece which pushes against a neoprene disk/washer - forces it radially out obturating the chamber.  It is swabbed clean with a wet sponge (as is the rest of  the chamber) after each shot.

There are some folks here that have posted in years past pix of black-powder breech-loaders - home built with screw-on caps.  I don't know the legal or safety/strength details of them.

[jeeper1]

I expect that the batf&e would consider a removable chamber a cartridge and therefore class that as a DD.

[moose53]

Here is a link to a old post on breech loaders  http://www.gboreloaded.com/forums/index.php/topic,93883.0.html  The design is about as simple as it gets. 

[Max Caliber]

Has anyone actually constructed a breech loader using a BATF approved design? If so, I would very much like to see pictures.

[Cat Whisperer]

I expect that the batf&e would consider a removable chamber a cartridge and therefore class that as a DD.

Which is EXACTLY the reason for asking for a ruling!

It may be ....

But it may also be ....

But then it could be ....

[dominick]

I believe the definition for destructive device says "Commercially available" fixed ammunition.  I'm not sure if the pre-1898 breech loaders that use fixed ammo "not commercially available" would be considered DD's.  The 15th century "mug gun" Peterara's [similar to Victor's design] are, from my understanding considered muzzleloaders because you still have to load the mug from the muzzle.  But DON"T take my word for it, I may be wrong.  I think it's still a good idea to check when in doubt.  Victor's design reminds me a little of the early Armstrong breechloaders with the exception of where the charge and projectile is loaded.  Personally, from a builders point of view, the muzzleloaders are a safer bet.  They are stronger, simpler and with proper safety procedures, [ie, safety rammers etc,] as safe as breechloaders.  In contrast, when it comes to legality issues you are also on safer ground with the muzzle loaders.  Also, other than it's uniqueness, the important advantages of a breechloader over a muzzleloader are for the most part, non-recreational.  I am not trying to talk anyone out of constructing a breechloader and I think a well researched and constructed one would be very rewarding.  I am just saying, enter the endeavour with caution.  Dom

[Victor3]

  I was thinking of making the powder chamber diameter smaller than the projectile diameter so that the projectile it would not fit into it. Projectile would be loaded into the back end of the bbl separately.

 I thought the design I posted would be okay from a legal standpoint since it uses elements from early designs and does not use fixed ammo. However, the removable chamber is from one design, and the screw is from another. I don't know if combining the two would qualify as an "antique design" according to the ATF or not. Best to assume not without a ruling from them, I suppose. I'll stick to a documented legal design if and when I make a breechloader.

 What I would like to do is come up with a simple bbl/breech design that will allow me to experiment for accuracy with different projectiles in a cannon made with a heavy-walled (1.25" OD) rifled 12 ga bbl that I have.

 Hey, I just thought of something I'll have to read up on - Maybe if I keep the bbl and overall length long enough, it would just be considered a shotgun. A semi-auto Browning 1919 is classified as a rifle by the ATF, so maybe I'm onto something here.

 Or, maybe I should just stop procrastinating by spending time here and do my dang taxes (but that's no fun)...

 

[KABAR2]

  I was thinking of making the powder chamber diameter smaller than the projectile diameter so that the projectile it would not fit into it. Projectile would be loaded into the back end of the bbl separately.

 I thought the design I posted would be okay from a legal standpoint since it uses elements from early designs and does not use fixed ammo. However, the removable chamber is from one design, and the screw is from another. I don't know if combining the two would qualify as an "antique design" according to the ATF or not. Best to assume not without a ruling from them, I suppose. I'll stick to a documented legal design if and when I make a breechloader.

 What I would like to do is come up with a simple bbl/breech design that will allow me to experiment for accuracy with different projectiles in a cannon made with a heavy-walled (1.25" OD) rifled 12 ga bbl that I have.

 Hey, I just thought of something I'll have to read up on - Maybe if I keep the bbl and overall length long enough, it would just be considered a shotgun. A semi-auto Browning 1919 is classified as a rifle by the ATF, so maybe I'm onto something here.

 Or, maybe I should just stop procrastinating by spending time here and do my dang taxes (but that's no fun)...

 

This is a case of apples and oranges.....

The semi auto 1919 series browning is NOT classified a
machine gun due to a denial island milled into a new
manufactured right side plate so full auto parts will not
fit. the internals are machined and highly modified so
they will fire in semi auto ONLY. a Browning 1919
Machine gun is just that, it is not classed as a DD .

The semi auto browning being classified a rifle
 would have no bearing on building with a rifled12 ga. barrel
 it could still be construed as a DD a good example is the street sweeper
all it is is a 12 ga. but atf has decided that because of its form
and function it is a DD. Use the 50 caliber or below rule
and be well.

Allen <><

[cannonmn]

You can get some insight into this by going back and looking at what happened with the "in-line" "muzzle-loading black powder" hunting rifle designs.  These were allowed until some makers stepped over a certain line, then the rules were clarified and certain designs ruled out.  I'm sorry I can't recall full details, but if someone happens to be well-versed on what happened there, maybe 5 or 10 years back, you could tell us.  I don't recommend at all trying to second-guess the gov't, or using the in-line history to apply to what's being discussed here, but I do think it would be "informative" at least.

[Cat Whisperer]

This is a good discussion.

However good the points are, the bottom line is what BATFE rules.

Suggest doing three things:

First, a thorough read of the BATF rules (use the link in one of our Stickies).  Get a clear understanding of what the law says (federal, state and local) regarding cannons (pre 1898 design or REPLICA), and certain key terms as cartridge loading, commonly available ammo, as well as OTHER categories of the law pertaining to SIGNALing devices and DD's.  That's three different areas of the law, not to mention fireworks.

Second, collect all the information on all the 'vintage' breech loaders you can find.  Williams gun is one.  Find the niche where you can fit legally into the law and still meet your design objectives.

Third, present an organized, illustrated and documented request to BATFE for a ruling. 

There is a fellow that makes and sells (legally) an adapter for AR's that shoots golf-balls.  it is legal from the perspective of it not being a 'firearm' but a device for recreation - which IS to say if it were used AS a firearm the owner would be violating a federal law with SERIOUS consequences.

Again, we're not lawyers, nor should you consider this as legal advice - go instead to the source.