Looking for tips & tricks on cutting a barrel

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huntingfish

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Hi guys,
I was wondering if anyone has any tips and tricks on how to cut a barrel? From what I gather, the cut has to be perpendicular to the barrel otherwise it might affect accuracy. Did anyone use special tools to make this cut and ensure it's straight?

Let me just specify that this is for a grouse gun I'll be working on (bought a rifle specifically for this purpose) and maximum shooting distance is 20ft or so. I don't care about sub MOA at 100 yards.

Cheers!

Fish
 
I use special tools. Have a hand crowning set, as well as a lathe.
The crown needs to be perpendicular to the bore, for best results.
There are barrels cut and crowned using a hacksaw, files and brass roundhead screws with grinding compound in a low speed electric drill.
 
Call me bubba. Cut it straight using whatever method you have available, a fixture and a hack saw, or a chop saw or vertical bandsaw. Make sure you make a test cut first to ensure the fixture is giving you a true perpendicular in all directions. Whatever you do, cut it longer than legal so you have room for a "do over" if necessary. I've only done it once, but i used a fixture I cobbled together to rotate the tip of the barrel against a grindstone, much like sharpening a drill bit, to finish the face. Then use a brass screw and grinding compound to finish the crown of the bore.
 
I would drive a bullet down the barrel to the cut zone . It will support the chrome lining during cutting, then drive out the half before you re-crown.

If you are gonna use a hacksaw
(i've done it) Use a cutting oil and do a few test cuts further up the barrel.

Good luck
 
Grizzlypeg said:
Call me bubba. Cut it straight using whatever method you have available, a fixture and a hack saw, or a chop saw or vertical bandsaw. Make sure you make a test cut first to ensure the fixture is giving you a true perpendicular in all directions. Whatever you do, cut it longer than legal so you have room for a "do over" if necessary. I've only done it once, but i used a fixture I cobbled together to rotate the tip of the barrel against a grindstone, much like sharpening a drill bit, to finish the face. Then use a brass screw and grinding compound to finish the crown of the bore.
Click to expand...

Hey grizz, I was thinking the same thing. I just wasn't sure what fixture one could use. I'll probably just put the barrel in a vise and hack at it.

John, would canadian tire or some similar store have cutting oil? Any brand names you can suggest? What's the advantage of using cutting oil?

Fish
 
Use a light 3-in-1 oil or spray jig-a-loo (princess auto) or even wd-40. I just seems to cut smoother and the cut surface is alot smoother too.
try the first test cut without and try the second cut with it.
John
 
The cut will need to be smoothed with at least a file so I wouldn't worry about cutting oil for your hand hacksaw.

Besides, if your barrel has a taper to it then you can't guage off the outside for a square cut anyway. What you need to do is figure out a way to guage the right angle to as close as you can see it and that'll be good enough for your needs from the sounds of it. What method you use will depend on your ingenuity and what tools and techniques you have available. And following all that go and shoot it and see how bad it is or isn't.
 
this a rifle or shotgun you are doing this on. as you said grouse gun, then said sub moa. one would typicaly be a shotgun (grouse) and moa isnt generaly used with shotguns.

for a rifle. cuz the bbl a little longer than you want. and use a file to file it straight on the end and get rid of the file marks. use a drill about twise the size of the bore and gently run it on the end of the barrel to crown the barrel. use the file to do the outside of the bbl.

as for a shotgun its roughly the same idea. just a bigger drill bit.
 
Hi guys,
Thanks for all the suggestion. I guess I'll give it a try without any oil. See how that works. Oh and I was talking about a rifle (it`s a .22), not a shotgun.

I should be getting the rifle soon enough and this will be one of the first thing I`ll have to do to it to get this project started (first being shooting it to see how accurate it is out of the box :D ).

I'll keep you posted on how it went! I had another related question though...Since I`ll be cutting the front sight, I'll need a replacement. However, I wanted to machine a piece from an aluminum block to make a nicer front sight. Is there any documentation online on what height I need my sight to be? I saw on the williams fire sight page (in their catalog) and they said to measure barrel thickness where the front and rear sights are and divide by two and add the height of the sights. This way everything is aligned with the center of the barrel. Is that the way to do it?

Cheers!

Fish
 
Remember that none of this will be easy if the barrel is tapered. It may not look like a lot but you won't get a good fit with a straight hole on a tapered barrel. You're going to need to get creative with all this.

I would not suggest using a drill to "crown" the bore. Drill bits used that way for deburring tend to take off the corner but leave a chamfer that is anything BUT round. If you must do it that way use a multi edge countersink bit. Also using a countersink or the brass screw and grinding compound trick to "crown" the barrel will only be as accurate as the front end is square to the bore. And THAT will depend on how well you guess at the filing of the end. There's no magical "bore seeking" crowning tool other than the piloted one that fits into the bore. LIkely with a bit of eyeballing using a small square and a file you'll get it "close enough" for what you seem to be saying you want out of it but nothing you'll be doing by hand will produce a truly accurately square end to the bore and a crown that is accurate using any of the methods listed here. The good news is that if decide you want it MORE accurate later on then a smith or machinist familiar with guns can make it right for you. And if it does shoot off to one side by a little but it's consistent then you can adjust for that with the sights so it's not the end of the world I suppose. It just depends on if it's consistent.

Remember that the barrel will lift a little when the charge ignites and before the bullet leaves the end. If your rear sight isn't adjustable for both range and windage you'll want to start with the front blade a little long and file it down slowly to bring the impact point at your desired range up bit by bit. Patience is this case is a virtue.

And I hope you realize that we're going to need to change your username over to Bubba now, right? :D
 
BCRider said:
Remember that none of this will be easy if the barrel is tapered. It may not look like a lot but you won't get a good fit with a straight hole on a tapered barrel. You're going to need to get creative with all this.

I would not suggest using a drill to "crown" the bore. Drill bits used that way for deburring tend to take off the corner but leave a chamfer that is anything BUT round. If you must do it that way use a multi edge countersink bit. Also using a countersink or the brass screw and grinding compound trick to "crown" the barrel will only be as accurate as the front end is square to the bore. And THAT will depend on how well you guess at the filing of the end. There's no magical "bore seeking" crowning tool other than the piloted one that fits into the bore. LIkely with a bit of eyeballing using a small square and a file you'll get it "close enough" for what you seem to be saying you want out of it but nothing you'll be doing by hand will produce a truly accurately square end to the bore and a crown that is accurate using any of the methods listed here. The good news is that if decide you want it MORE accurate later on then a smith or machinist familiar with guns can make it right for you. And if it does shoot off to one side by a little but it's consistent then you can adjust for that with the sights so it's not the end of the world I suppose. It just depends on if it's consistent.

Remember that the barrel will lift a little when the charge ignites and before the bullet leaves the end. If your rear sight isn't adjustable for both range and windage you'll want to start with the front blade a little long and file it down slowly to bring the impact point at your desired range up bit by bit. Patience is this case is a virtue.

And I hope you realize that we're going to need to change your username over to Bubba now, right? :D
Click to expand...

I was thinking of using a dremel conical bit to do the crowning.

Fish, erm , I mean, Bubba ;)
 
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