I just bought a rifling button so I can make my own 9mm barrels
You need a five ton press to push this button down a barrel to form
the rifling. OK, what would be the highest strength steel i can get
for the pusher. I looked for HSS and couldn't find anything long
enough. looked for already hardened drill rod. It must be out there
but no joy so far.
My first barrels will be 12", want to do 16" in the future.
If the bar can be 0.35" diameter, you're looking at less than 0.1 ^2
in. of area. Yikes. You need 100 ksi compressive yield strength in the
bar to handle the full five tons.
HSS is no stronger than many high-strength alloys. Pre-hardened,
ground drill rod is available.
Another possibility is the bar stock from Timken and others, intended
for making roller bearings. That stuff runs upward of 180 ksi tensile.
In most steels, compressive strength is close to, and directly related
to, tensile strength. And tensile specs are easier to find than
Music wire in these dimensions is not nearly as strong as the thinner
Ed Huntress (remove "3" for real email address)
You need a small steel supplier or a steel service center that will
sell you a little piece. They don't want to, but sometimes they're
If it were me, I'd look into Timken's list of suppliers:
...and get on the phone with them. Tell them frankly that you need one
piece. They may know of a supplier who will do it for you.
Or you could become a manufacturing magazine editor and ask for a
Timken bearing steel is the high-end solution. Really, 0-1 is more
than enough. It's typically delivered in one of three conditions:
annealed, as-rolled, and hardened. As-rolled is Rc 50. Its compressive
yield strength is 196,000 psi -- 'way more than you need.
That's probably the easiest one to get, because small steel suppliers,
and even online hobby suppliers and *maybe* Brownell's, deal in
onesies and twosies of that material.
Crack!...goes an expensive piece of carbide. It's not tough enough for
futzing around with a small-shop press.
Again, good luck. You shouldn't have trouble finding a piece of steel
that's strong enough, although ordinary mild steel might turn to mush
under that much compression. Go for a good, common alloy steel, or
maybe a hardened piece of 1070 or1090 carbon steel, and you should be
able to do it. At that small diameter, even cold-rolled high-carbon
should do it. Cold-rolling hardens small diameters much more than
(I always thought they pulled, rather than pushed, rifling buttons,
but maybe that's just the gun manufacturers.)
Thanks, not bad advice for a flaming liberal from KCB.
<ducking and running>
Push type buttons are cheaper, fits my lifestyle. Also, from what I've
read, pull type actually fail more easily. The pull rod breaks right
where the threads end.
Yeah, I could see that.
I guess I told about the rifling tool we used in my old shop to make a
muzzleloader pistol barrel. It was an adaption of the tools that
Pennsylvania rifle builders used over 200 years ago. We stacked a few
pieces of hacksaw blade side-by-side into a tool we made from drill
rod, with one slot in the side to hold the blades. We shimmed under
the blades to adjust cut depth, progressively through multiple
For a final finishing pass, we ground a lathe bit to fit in the slot
and cut a couple of tenths to make the grooves flat and smooth.
The tool for controlling twist was a 3/4" piece of square bar that we
clamped at one end in a monster vise, put a big pipe wrench on the
other end, and twisted. This was pinned to the cutting tool and drawn
though a piece of plate with a square hole in it. Indexed four times,
we got a four-groove barrel.
My partner in that job shop had apprenticed to an antique gunsmith
(both the guns and the smith were antiques) in New Hope, PA. He
learned a lot of tricks and made several rifles and a bunch of horse
pistols from scratch.
On Thursday, September 19, 2013 8:46:12 AM UTC-4, Ed Huntress wrote:
I am a frugal person so my suggestion would be to go to your auto salvage y
ard and if you can find it, get a torsion bar from a Nissan Truck. Second
choice would be an axle shaft. Both will require reducing the diameter usi
ng a carbide bit. But if you do use steel from a auto wrecking yard, try t
o get steel that as close as possible to the diameter you want. Not only f
or less machinging , but I am not sure how deep the heat treatment goes on
axles and torsion bars.
On Thursday, September 19, 2013 11:25:28 PM UTC-4, firstname.lastname@example.org wrote:
yard and if you can find it, get a torsion bar from a Nissan Truck. Secon
d choice would be an axle shaft. Both will require reducing the diameter u
sing a carbide bit. But if you do use steel from a auto wrecking yard, try
to get steel that as close as possible to the diameter you want. Not only
for less machinging , but I am not sure how deep the heat treatment goes o
n axles and torsion bars.
After posting this, I looked around the internet and found that most car ax
les are now made of medium carbon steel. But also found Admiral steel near
Chicago that sells to knife makers . And they sell 52100 steel in 3/4 inc
h dia at reasonable prices.
About 3$ for 12 inches of 3/4 dia 52100 steel. About 6$ for 24 inches.
On Thursday, September 19, 2013 6:18:44 AM UTC-4, Karl Townsend wrote:
Would a solid carbide bar work as a pusher?
5/16" by 12" sold here for instance:
This is why pulling buttons is preferred of course.
Didn't you say you were doing the gun drilling on a Hardinge CNC?
If so, don't they have a max of 12" in Z axis travel?
How's that all going to work out?
Thanks for the carbide lead. A push button was in my (super cheapo)
I'm going to modify a turret plate with a 1.375 square by real long
gundrill tool holder. Drill 12", back up and stop. Loosen holder,
slide ahead, restart drilling. I'd use a manual lathe but the hardinge
has a nice flood coolant setup and complete enclosure.
On Thursday, September 19, 2013 9:00:34 AM UTC-4, Karl Townsend wrote:
Ahhh, very clever that.
I would think your push bar problem is less about compression and more about bowing.
An uneven force will cock the button off center for a bad result...as far as I understand it.
I've heard of using hydraulic force to push a button through a (threaded) barrel.
I wonder if some type of a grease gun would have enough pressure?
Will look forward to updates on your progress.
I am still hoping to make a reproduction rifled barrel for my .177 air pistol some day.
On Thu, 19 Sep 2013 13:07:56 -0400, Ed Huntress wrote:
Certainly once it's well in -- but if those things work the way I think
they do, getting it started would be critical.
Of course, I'm just extrapolating from the term -- I haven't even hunted
up a YouTube video of the process.
That's a good point. Maybe a guide wold be needed. Also, maybe that's
a good reason for pulling rather than pushing. That's the case with
very long (often over 12 feet), thin broaches. Beyond a certain length
and minimum diameter, they're usually pulled.
But they have guide bushings if they're pushed. With the skinny push
rod talked about here, you'd certainly need some kind of help at the
beginning of the push.
On Thursday, September 19, 2013 at 10:07:56 AM UTC-7, Ed Huntress wrote:
So, does this mean your pushrod can be a stack of dowel pins, all ground flat on the
ends? The case-hardening of a dowel pin makes good burst (compressive) strength,
and a dozen two-inch pins doesn't break the piggy bank.
Hydraulics might work, but that just makes this BIG project. Easily available
hand pumps will do 10kpsi, fluids will go to 50-100 kpsi (with custom pumps).
If the pushrod is a piston, 0.3" diameter, it only gets 900 lbs force with
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