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| inonickname |
 Posted: 07/13/2009 1:34 AM Post subject: How-to: rifle metal barrels |
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Major General
Joined: 07 Dec 2008
Posts: 2487
6556.71 Spud Bux
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Everyone wants a nice rifled barrel don't they? This will work better on softer materials, such as aluminum. You will need a file, vice, welder, steel rod longer than your barrel and a lot f patience. You will also need to head down a hardware store to by a bolt.
This was inspired by the guy on spudtech who did something similar
Firstly go down your hardware store with a small piece of tubing the same size as your barrel (if they sell it, use some of theirs). Now go and look through the arrangement of bolts and find one with a hex head a good size for your barrel.
A good guideline would be that when centered in the barrel the ends of the hex head protude perhaps halfway into your barrel material (assuming you have a thinwalled aluminum or copper barrel).
Now you have selected your bolt, protect the threads with some tape and put it in your vice. Firstly, create an angle on the bolt head to make cutting easier. Leave the back of the bolt head basically intact.
Next, use your file to cut at an angle across the hex head that you want your rifling to be at. Keep it the same way the whole way around, and dont make it too steep. Cut it on the either side of each bolt head and file the end tip of the bolt to be sharp.
And once complete..
Then just weld it onto a steel rod and you're away!
It may take several tries to get a good final product. Chances are, because it's done by hand the depth of each cut will differ slightly. Once the first row of riflings are cut, rotate the tool and cut again until they are all a consistent depth.
This tool basically pulls itself along.
After rifled, first spin sandpaper on a rod (using a drill) inside your barrel to smooth it off, then insert a rag with an abrasive or buffing compound, such as jif for cleaning saucepans. After that, use some clean cloth and spin it with the drill until polished.
More pictures will be up tonight |
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| inonickname |
| Posted: 07/13/2009 1:36 AM Post subject: |
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Major General
Joined: 07 Dec 2008
Posts: 2487
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| Wow, the pictures came up even worse than I expected. Kodak C310's are crap, they never focus on what you aim at..but check out the items in the background. |
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| frozebyte |
| Posted: 07/13/2009 2:43 AM Post subject: |
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Sergeant First Class
Joined: 24 Jun 2009
Posts: 136
110.29 Spud Bux
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Yeah they really focus on the background and not what you want it to focus on. I bet your camera phone would work better 
A pity it only works on aluminium, think the bolt is not as strong as mighty steel.
Cheers. |
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| inonickname |
| Posted: 07/13/2009 4:16 AM Post subject: |
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Major General
Joined: 07 Dec 2008
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| frozebyte wrote: | Yeah they really focus on the background and not what you want it to focus on. I bet your camera phone would work better
A pity it only works on aluminium, think the bolt is not as strong as mighty steel.
Cheers. |
The bolt is steel. It will rifle copper. If you are rifling steel or harder then you should look into a carbide bit and a jig to hold it.
I just cut the riflings into my 1.2m barrel and in a test jig the groupings are noticeably closer at mid range. |
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| frozebyte |
| Posted: 07/13/2009 5:58 AM Post subject: |
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Sergeant First Class
Joined: 24 Jun 2009
Posts: 136
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| Yup im using steel. Im not looking into complicated things so i'll probably continue doing the basics before i go into doing any further mods. Still a beginner :] |
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| Hotwired |
| Posted: 07/13/2009 6:35 AM Post subject: |
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UK Spudgunner
Joined: 13 Oct 2006
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Ehhhh....
| Quote: | | Focus range 2.8 ft (0.85 m) to infinity |
I agree, that camera is not too hot for close pictures.
What are you planning on firing from the rifled barrel? |
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| inonickname |
| Posted: 07/13/2009 7:11 AM Post subject: |
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Major General
Joined: 07 Dec 2008
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| Hotwired wrote: | Ehhhh....
| Quote: | | Focus range 2.8 ft (0.85 m) to infinity |
What are you planning on firing from the rifled barrel? |
Lead slugs at 400 psi with hydrogen 
I rifled it and it went fine, even if they were perhaps slightly shallow. |
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| Ragnarok |
| Posted: 07/13/2009 9:17 AM Post subject: |
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Lord of Karma
Joined: 19 Dec 2006
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| inonickname wrote: | | Lead slugs at 400 psi with hydrogen |
Sounds like a waste. At those pressures and that calibre, hydrogen will do relatively little for performance. The muzzle velocities with lead slugs just aren't going to be close enough to air's speed of sound (in air) that the higher SOS of hydrogen will offer much increase in velocity.
For this situation, I don't think that's really worth the additional complication of using hydrogen - it's of course up to you, but that effort and time for a projectile of that weight? |
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| Moonbogg |
| Posted: 07/13/2009 10:09 AM Post subject: |
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Major General
Joined: 13 Oct 2008
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| Most people don't have welding stuff. An alternative would be to get a tap and tap the inside of the tube and screw the bolt in. Maybe you could even find some inside threaded shaft or something. Sweet rifling idea you got there. |
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| Hotwired |
| Posted: 07/13/2009 10:41 AM Post subject: |
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UK Spudgunner
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A large hex nut welded/epoxied to a threaded rod could do the business too methinks.
Depends what you've got available. |
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| jimmy101 |
| Posted: 07/13/2009 11:11 AM Post subject: |
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Lieutenant General
Joined: 28 Mar 2007
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| Hotwired wrote: | | A large hex nut welded/epoxied to a threaded rod could do the business too methinks. |
Or join a hex bolt to "all thread" with a threaded coupler.
inonickname:
How many turns per foot in the rifling?
If your camera's minimum focus distance is 2.8' then just shoot at that distance. You can expand and trim the photo later. Most digital photos are much too high of resolution anyway, compared to what is needed to display on a computer monitor. A computer really only needs a 100 DPI image. A 5 megapixel image is more like 300-500 DPI (depends on the size of the print). So, for use on a computer monitor you can zoom in (then trim) by at least 3x, and maybe as much as 5x without loosing any detail. That 2.8' minimum focus distance then affectively becomes 7"~11". |
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| Ragnarok |
| Posted: 07/13/2009 11:37 AM Post subject: |
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Lord of Karma
Joined: 19 Dec 2006
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| jimmy101 wrote: | | Or join a hex bolt to "all thread" with a threaded coupler. |
The threaded coupler will presumably be the same size as the (unmodified) bolt head - i.e. too big to fit down the barrel. |
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| john bunsenburner |
| Posted: 07/13/2009 12:15 PM Post subject: |
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Major General
Joined: 19 Oct 2008
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| One can braze the bolt to the rod, just put a wet rag over the cutting bits so you don't make them soft. |
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| jhalek90 |
| Posted: 02/28/2010 8:52 AM Post subject: |
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Lieutenant Colonel
Joined: 14 Aug 2009
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umm. can i possibly get a better picture of the finished bolt head?
I dont understand how it spins as you pull it along.
Even a simple paint diagram would be nice. |
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| POLAND_SPUD |
| Posted: 02/28/2010 9:15 AM Post subject: |
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Lieutenant General
Joined: 13 Oct 2007
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uhmmm... I guess you could work that out on yourself
something like this 
but of course the twist rate has to match the riffling rate you want to achieve |
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