I cut my shotgun barrel down.

[Fumbler]

I'm no gunsmith, but I thought I'd share my weekend project.

The gun is a Mossberg 500A with vent ribbed 24" barrel.
I decided to shorten the barrel for use as a home defense and deer hunting slug gun.

I pulled the vent rib off, knocked off the blocks that held the rib on, marked the barrel at 18.5", and cut it with a hacksaw.
Here's a not so great pic of the muzzle:
http://www.thewolfweb.com/photos/00411951.jpg
Note: the server doesn't allow hotlinking, so you have to copy and paste the image location into the address bar.

I cleaned up the muzzle with a mill bastard file. The finished muzzle came out quite nice and flat, but is not square with the barrel. It is about 0.004" longer at the bottom.

I plan on making a crowning tool on a lathe once I get around to the campus woodshop, so that will fix the squareness issue.

Here is a pic of the gun:
http://www.thewolfweb.com/photos/00411952.jpg

I still need to file flat the points where the rib was attached and solder on the front sight (Mossberg factory Ghost Ring setup). I'm going to refinish the whole gun in industrial epoxy, Sherwin Williams Ind. Epoxy, the same stuff as Duracoat.
It's nothing fancy, but fancy isn't the name of the game when you don't have much equipment.

Some questions:
-Will 95%tin/5%silver solder work for the front sight? Melting point is 430°.
-The barrel wall is non concentric. If facing the bore, the 1-2 o'clock area is 0.006" thicker than the opposite side. Will this have any practical affect on accuracy?

 

[MudPuppy]

Some unasked for advice -because I can't answer the actual questions you asked - I've found a pipe cutter to be a cheap, efficient way to cut a barrel. Still needs cleanup, but gets a "straighter" cut (90deg) than a hack saw.

 

[Fumbler]

My dad has a pipe cutter and I tried it, but the wheel is missaligned and it doesn't cut straight.

The problem isn't my hacksawing skills, it's the fact that the line wasn't 90° :banghead:

 

[kimbernut]

shotgun barrel trim

We use that which is available to us.I have a friend who was given an Ithaca mod.51 20ga. The gun was nice but had an ugly 2" deeply pitted rust spot beginning 1.5" from the muzzle. we fashioned an appropriately sized dowel plug for the chamber end of the barrel with a centered point facing rearward and cut 4" from the barrel length with an electric arrow cut-off saw that I still have mounted to my workbench.the dowel plug was solidly against the nock plate and the thin carborundum blade did an excellent job on the barrel and vented rib all in one cut. We slowly turned the barrel just as we would our aluminum arrow shafts and made the cut just at the edge of a rib section. Put a new bead sight in place and went bird hunting.It's cylinder bore now but made a great quail gun.

 

[Fumbler]

That's a pretty nifty method.

 

[GaryK]

I bought an old 12ga 870 to use for home defense. I used a hacksaw and cut the barrel in middle of the first mounting point on the vent rib that was greater than 18". I was careful and made a pretty straight cut. I cleaned it up with a file and sandpaper, and toughed up the bluing with some Oshpo. It looks pretty good.

 

[Shalako]

A simple trick for marking a square cut in any round stock or material, is to wrap a piece of cardstock around the tube. The cardstock must have a perfectly straight edge where you want to mark your cut. Wrap it as tight as you can. If it is off by the slightest degree the edge of the cardstock will not line up with itself when you make it around the tube. Fiddle with the cardstock until it makes a perfect circle around the tube. Mark the edge for the cut with a scratch awl.

Cutting is a little tricky with a hacksaw. I like to tape the side of the line I want to keep to prevent scratches. Carefully glide the hacksaw along the waste side of the line to just barely cut into the metal. Rotate the tube about 15 degrees and carefully make another scratch/cut. Repeat. When you make it all the way around the tube with the scratch/cut, you can start to go a little deeper on your cuts. Always rotate the tube after each incremental cut to make sure your tube is cut precisely on the side of the line you marked with the cardstock method. Eventually you will cut through the tube and can then file off the burrs with a mill file. Polish with successively finer grits of wet-or-dry sandpaper going only in a back and forth motion. With each finer grit of sandpaper, you go back and forth but at a 90 degree angle to the previous grit until you can't see any scratches from the previous grit. Eventually it will be mirror polished if you are so inclined. Then blue according to the directions on your chosen product.