SpudFiles

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

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.

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.

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.

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 :]

Ehhhh....

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?

Hotwired wrote:Ehhhh....

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.

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?

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.

A large hex nut welded/epoxied to a threaded rod could do the business too methinks.

Depends what you've got available.

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".

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.

One can braze the bolt to the rod, just put a wet rag over the cutting bits so you don't make them soft.

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.

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