Interchangable barrels... on a CO-AXIAL

boilingleadbath · Posted: 08/05/2005 9:10 AM Post subject:

First, let me say it's unique for a reason - it's a pain compared to the normal way.
Second, let me say that as far as I know, my cannon is the only one as of 5-august-2005 that uses this system. Only the second co-axial that I know of that has any meathod of changing barrels.
Thirdly, if you have a removable barrel of the origional diameter and length with a threaded adapter on the end, you can use these barrels in that launcher. So don't use "I don't want to use my 15$ riffled barrel on a single launcher" as an excuse.

Ok, so you built an awsome co-axial launcher. You now want more barrels. Let's hope you have a threaded adapter on the end or a place to put one, or you'r stuck with one barrel.

"Old barrel" will hensforth be used to talk about the barrel you origionaly used in the construction of the launcher.
"New barrel" will hensforth be used to talk about the barrel you'r making to use in that launcher.

Materials:
New barrel sized pipe.
Old barrel sized Male adapter.
Old barrel sized Female adapter.
New barrel sized x old barrel sized reducer bushing.
New barrel sized fitting(s) that are too big, or just the right size, to fit in the old barrel.
New barrel sized Female adapter. *optional*

Directions:
First, solvent weld a threaded adapter to the end of the barrel. I prefer female - you'r less likly to hit the threads on something and screw them up.

Next, get a fitting for the new barrel size that is too big (or exactly the right size) to put in the origional barrel. For example; to make a new 1.5" barrel for a 2" barreled launcher, you would take 1.5" fitting (couplers work awsome - I'd buy the PW ones for the added length, but you could get away with 1 or 2 DWV ones).

Once you have that, cut it into short rings if it's a coupler; a 1" (or 1/2 the fitting, your choise) long one, and as many about 1cm ones as you want. Otherwise, leave it as it is. These will, post modification, support the new barrel in the old one, and form a primative gas seal.

Once you have your future suports, reduce their outside diameter untill they fit (fairly snugly... remember what their being used for. AND NO CHEATING - DOING THE REMOVAL HERE INSTEAD OF AT THE END RESULTS IN SHODDY WORK! (you won't get this yet, but you will when we get to the end)) in the old barrel. You'r done with them, for now.

Now, take your (old barrel sized * new barrel sized) reducer bushing, and remove the stop just as if you where making a co-axial launcher.

Once you have that prepared, solvent weld it to your (old barrel sized) male adapter. (assuming you have a female adapter on your old barrel)

After that assembly has set up, solvent weld BACKWARDS onto your new barrel, leaving about 1.5"-2" of new barrel sticking out behind it, if you got the optional new barrel sized female adapter. Otherwise, have the end of your assembly flush with the end of the new barrel pipe.
Solvent weld the optional female adapter, after removeing part of the stop, (or male, if you prefer) onto this 1.5-2" of pipe sticking out.

Nearing compleation, cut your new barrel pipe so that when you thread the thing on, it will come up .5" short of the end of your old barrel pipe. Remember that these fittings don't screw all the way in! I recomend that, previous to constructing this, you'v measured the distance they do go in!

Now, take your support rings and place them an equal distance apart on your new barrel pipe. The wide one I had you make goes on the end farthest away from the fitting. The ones that go in the middle should be relitivly loose fitting.
Solvent weld these in place. The ones in the middle hold no pressure, so you can use just cement on just the pipe. However, use proper technique on the wide one at the end - it does hold pressure (that's why it's wider)

Wait a day or so, and... You might be done! However, if your ammo gets stuck in muzzle of the new barrel, or your you can't put the new barrel in the old barrel, your pipe and rings may have swelled up with the solvent. Get out that dremmle and enlarge/reduce their size.

Now, your done. Very Happy

Have I convinced you not to do it? Oops! Embarassed

Pictures of What the @$%^ I'v been talking about:

(more to come in the morning)