Converting .22lr rifle barrel to smooth bore

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m_falafel

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I’ve been researching the subject on the web without finding much... I want to do it myself with pretty much only standard tools, I don’t want to pay 499$ for Henry’s Garden Gun so I am ready to take the risk scrapping an old beat up rifle instead.

The only forum post I found on that matter suggests using stainless steel bore brushes to literally sand the rifling inside the barrel until it disappears. Any other suggestions? I do not for hope for a perfectly smooth bore, only something that won’t throw my .22lr shot in a donut style pattern.

Thanks!
 
Smooth bore .22's need a little choke for any kind of a pattern... and even when you have that you will be lucky to kill anything with it...

I had a factory Remington 22 skeet barrel and a grouse sitting on the ground at 10 feet would fly away... quite possible to die somewhere else. You could see shot in the dust all around the grouse so I am sure he was in the middle of it.

Removing the rifling is best done with a fairly long reamer with a long taper at the front of it... and then honing it. A reamer and a hone shouldn't cost much more than a couple hundred dollars...

I think .22 shot is effective on snakes at a distance of 3 feet.... maybe...
 
I did a bit of research on this a while back. Found a few guys that had done it using a stainless steel boar cleaning brush. . I have been Keeping my eyes open for a suitable brush. Have found a couple fine spiral brush’s. My plan was throw the barrel in the lathe. Use the stainless brush with course valve lapping compound.
 
guntech said:
Smooth bore .22's need a little choke for any kind of a pattern... and even when you have that you will be lucky to kill anything with it...

I had a factory Remington 22 skeet barrel and a grouse sitting on the ground at 10 feet would fly away... quite possible to die somewhere else. You could see shot in the dust all around the grouse so I am sure he was in the middle of it.

Removing the rifling is best done with a fairly long reamer with a long taper at the front of it... and then honing it. A reamer and a hone shouldn't cost much more than a couple hundred dollars...

I think .22 shot is effective on snakes at a distance of 3 feet.... maybe...
Click to expand...

When I was a kid I used one on the tractor for rats when moving bales out of the hay/straw barn. Was quite effective with little chance of damaging anything other than the rats. Most shots were 15 ft or less and you had to be fast. It was a lot of fun.
 
Go on the Aircraft Spruce and Specialty site and find some 4140 (Chrome Moly) tubing the right size and use it as a liner.
Supposedly, this is the stuff that gets button rifled for making .22 cal liners.
Hydraulic tube is usually spec'd by outside diameter and wall thickness. By memory you are looking at 5/16 OD tube, by whatever wall thickness it takes to get you into the .219 inch to .223 inch ID. I'll let you do your own math on that, but it's gotta beat all hells out of hours of trying to clear the rifling out of a barrel with grinding paste.

Much easier to drill out the hole you need when you are not completely concerned with it coming out perfect. The usual drill for lining .22 barrels is an 8mm drill with a .22 cal pilot on the tip, but guys have done lining by drilling in from both ends with an aircraft long drill. Otherwise you need to silver solder an extension on to the drill.

IIRC, a Number 2 size machine reamer will work to cut a chamber. I suppose if you were not fussy, a Number 2 drill bit would do. It's not like you are looking for match grade accuracy, just safe and functional.
 
Mossberg also made a .22 shot barreled rifle.
Make a reamer out of a drill bit of the correct size to only remove the rifling .solder it to an old cleaning rod.

Mossberg Targo model 340tr
Mossberg Targo model 42tr
 
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trevj said:
Go on the Aircraft Spruce and Specialty site and find some 4140 (Chrome Moly) tubing the right size and use it as a liner.
Supposedly, this is the stuff that gets button rifled for making .22 cal liners.
Hydraulic tube is usually spec'd by outside diameter and wall thickness. By memory you are looking at 5/16 OD tube, by whatever wall thickness it takes to get you into the .219 inch to .223 inch ID. I'll let you do your own math on that, but it's gotta beat all hells out of hours of trying to clear the rifling out of a barrel with grinding paste.

Much easier to drill out the hole you need when you are not completely concerned with it coming out perfect. The usual drill for lining .22 barrels is an 8mm drill with a .22 cal pilot on the tip, but guys have done lining by drilling in from both ends with an aircraft long drill. Otherwise you need to silver solder an extension on to the drill.

IIRC, a Number 2 size machine reamer will work to cut a chamber. I suppose if you were not fussy, a Number 2 drill bit would do. It's not like you are looking for match grade accuracy, just safe and functional.
Click to expand...

Just checked Aircraft Spruce's website. They list 4130 tube #03-0080 5/16x.049 wall 0.215ID @ $14.50 per foot.
 
I don't have advice on the barrel conversion, just encouragement for the concept. I used .22 shot shells to kill hundreds of English sparrows inside our barns as a kid, with a rifled bore .22 and agree with the disparaging comments about range and pattern quality and lack of general effectiveness. But years later I got a Remington targetmaster smoothbore that I used for pest control in and around our feed mill. What a difference!
It was completely effective on sparrows and rats at 10 yards or a little more, Maximum effective range on sparrows was about 15 yards. Even pigeons were cleanly killed at somewhat closer range. But, trying to kill a grouse with the #12 shot is ridiculous. Without a lucky hit to the brain, the individual pellets do not have the energy to penetrate to the vitals and humanely kill such a big bird.
Good luck with your project!
 
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If you pattern a 22 rifled barrel with shot , you will see a nice donut , you need to miss to hit. I have that part down real good.
I had a terrible leaded pistol barrel, in a colts woodman, it worked very well, before I deleaded it. But still no good for long shots.
I think if you spent a lot of time with a stainless brush, you will still have the lands, jus larger.
If I was going to do this, a heavy old 177 pellet rifle barrel could be had for minor money, drill, and some choke would be good, if you had the tooling , could be forged in.
Than fit that to your receiver 10/22???????????
This is better after 3-4 shots of scotch , late at night. or 3 AM

Longwalker, any choke that you know about?
 
I don't know if that Remington had any choke, but i doubt it, since I could not see any by looking through the bore and didn't feel any when running a tight patch through it. I gave the gun ( I almost wrote "rifle" LOL) away to a young couple who were having squirrel troubles at their acreage. So I can't check for you, sorry.
 
6mm flexhone brush mounted in some drill rod or 4mm drill rod with a slot cut in the end and sandpaper wrapped through the cut and around the rod, spin in hand drill
you can create a "choke" or "backbore" by varying the time spent on each section of the barrel. I would try the sandpaper option first, even if its just to knock the sharp edges off the rifling to save some wear on the flexhone.
 
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