rifling worm marker pattern

[tyro]

in Foxfire #5 about 1976 in the gunmaking chapter an old time blackssmith (I believe it was Charlie Blevins?) showed how he laid out the lines to mark the worm for carving. He also gave a formula for establishing the pitch on the right triangle he had drawn. It's just been too long and I cant remember what that formula was, anyone know it and like to pass it along? thnx ty

[Metalshaper]

simplified version... lay out a right triangle on the floor. ( or table or wherever your gonna do this )

the vertical line is the measurement for the length of twist..  the horizontal line ( at  90 degrees to the first ) is the measurement for the circumference of the worm.  the diagonal line that completes the triangle,, is where you lay down a chalk line..

Lining up the worm/blank  with the vertical line of your triangle.. roll the worm out over the diagonal chalk line..  IF all was done right.. there should now be one spiral marked out around the worm/blank..   more grooves, do the same or use the first as a guide to lay out the rest...

Hope this helps???

Respect Always
Metalshaper/Jonathan

[tyro]

Metalshaper,
Thank you so much.I was using the Beetle Bailey memory process...but no matter how hard I hit the tree I couldn't jar the memory! Ty

[John SMOthermon]

Steps in making a rifling machine.
1. Measure length of each revolution of the spiral on line A-B (Horizontal line) If you desire 1 turn in 48" to point C (approx.48 " from point A along the line towards point B is where point C is shown)
2. Now measure the circumference of the pole/worm and drop down that distance  say 9" at a 90degree angle from point C this will establish point D.
3. Now stretch a chalk line from point A to Point D and beyond. This should all be done on a flat surface.
4. Place the pole along line A-B and roll it straight across the chalk line thus making a spiral line along the length of the pole.
5.Figure how many grooves are needed ,and what their widths must be in order to come out even around the pole/worms circumference,and using the first line as a guide ,begin cutting.

[John SMOthermon]

I guess I should learn to type faster 

[Ken G]

Like Metalshaper suggested...............
1) Measure the circumference of your worm.  Mark a vertical line on the floor the same length.  
2) Decide what twist you want.  1 in 48 is an example.  Mark a 48" horizontal line at a 90 degree angle to the vertical line.  
3) Place masking tape on the floor with the sticky side up. The masking tape should intersect the top of the vertical line and the end of the horizontal line forming the diagonal line of a triangle.
4) Roll your worm over the tape and it will stick to the worm giving you the first groove.  
5) Divide your circumference by the number of grooves you want and mark the rest.

If you are really interested in building a rifling bench, I would suggest purchasing Steve Bookout's book "A Wooden Iowa Rifling Bench"
http://toadhallrifleshop.com/rifling-dvd-2/

[Ken G]

You type faster than me.   

[tyro]

You all type faster n' me!
Thank you all. I saw the bench that Dave Rase built...that was fantastic! hope mine turns out half that nice.THNX again Ty

[tyro]

The tape idea works fer me! I'll make the groves the same width as the tape and wont have yo do anything but stay inside the lines...then make a scratch block to mark in and out lines for the rest. Now I have a mission while I wait for the doc to let me go back to work...thnx Ty

[davec2]

A little off topic, but another way to easily make a rifling guide.  Just a twisted steel strap or bar run through a rectangular or square hole.  Easy to do a gain twist as well. 

Many years ago, I saw a guy make a rifle barrel out of a piece of rebar in Pakistan with a rifling rig like this one.

[Acer Saccharum]

Dave, thanks for the photo. That's a terrific testament to ingenuity. Where there's a will, there's a way.

[dannybb55]

That is a pretty nice machine, It looks like the ones used in Sweden in the ate 19th century. Repar must suck though, I thought that rr track rail was common.

[tyro]

that machine reminds me that we should never "misunderestimate" our opponents. Sort of like bamboo arrows with c rat end heads...re bar is carbon steel and last time I tried running off with a railroad track it wouldnt fit in my pickup..Ty

[tyro]

what do you figure the twist is in that machine bout 1/9 maybe? comparing his hands as a measure... as far as getting off topic any knowledge I can get from this vast trove of experience is deeply appreciated...thanx Ty

[TMerkley]

I like the automatic oiler!

[David Rase]

tyro,
I ditto what Ken G stated about getting Steve Bookouts " A Wooden Iowa Rifling Bench"  I have 2 other books and Steve's was the first to make sense to me from start to finish.  
Here is a link to my finished bench using Steve's instructions.
http://americanlongrifles.org/forum/index.php?topic=16823.0Dave

[tyro]

Thanx David. I saved your pictures to use and will pick up His book for sure...got Xrays back today not broken but tore tendons and ligaments in shoulder..so i'll be enjoying the stuff you guys post till all the king's men round up some more horses...                                One thing for sure, I'm seeing more ideas from the work I've seen posted... I'll have fun seeing how much better I can do than my first CVA  kit.TY