push button rifling

[Dave W]

So, assuming you had some push buttons and a barrel blank, and you want to push a button through... how the heck do you push a button through a two foot hole with a 1/4" or so rod, without having it buckle?

 

[akajun]

never heard of push button rifling, I went to Shilen this year and watched them pull buttons through. That was actually about the fastest part of the barrel making process I witnessed. Took all of 10 seconds per barrel. Gundrilling the first hole was the longest.

 

[billzweig]

As far as I know push button rifling is only used for handgun barrels where the push distance is just inches.

 

[GGaskill]

At one time, Hart Barrels reputedly used push buttoning to rifle their barrels but I see no reference to that on their website.

The bore will prevent the push rod from buckling; presumably there are a number of guides for the rod before it gets to the bore.

 

[Anthony]

Push button rifling is when you push the green button on the panel to start the process. I thought everybody knew that...

 

[partsproduction]

One website I found showed a drawing of a long square tube with thin dividers (Or stabilizing squares) set along the push rod. These dividers keep the rod from buckling which is the way they fail. When each divider gets to the muzzle it stacks on the last one, then the next etc., so that the rod needs to be only maybe an inch longer to account for the entire stack.
Solid carbide rods are what I've used, bought in ebay from Israel. They are very stiff.
But so far I've only made a few pistol barrels.

The other thing about rifle barrels is that you would need a longer ram than most power presses have, but whatever you use you'll want everything to set very square between the pressure and the resistance, ie the button. If there is any displacement off square the pressures will find them.
For my pistol barrels I threaded the ends and screwed on thick steel discs to force the barrel to point directly at the ram face center, and I haven't broken any pushers yet.

 

[Butch Lambert]

Hart still pushes buttons.

 

[Anthony]

A little OT but modern rifled cannon barrels are broached using the push method.

 

[partsproduction]

modern rifled cannon barrels are broached using the push method.

Please specify which cannons? Military artillery barrels are hammer forged, I don't know if they are forged over a rifling mandrel, the day of really large guns has been superseded by missiles.
Do you mean rifled tube liners for reinactor's cannons? I actually spoke with a fellow who uses a single point sine type rifling machine he designed and built for making cannon barrels, but don't know if he is pushing or pulling the tool head.

 

[Butch Lambert]

A little OT but modern rifled cannon barrels are broached using the push method.

Anthony, Pushing a broach is not pushing a button.
A broach cuts and a button irons the rifling.

 

[Davester]

https://m.youtube.com/watch?v=yrNakx3lStY#fauxfullscreen

 

[partsproduction]

The video was very enlightening. Thanks.

 

[Butch Lambert]

https://m.youtube.com/watch?v=yrNakx3lStY#fauxfullscreen

Stan and Tim make great rifle barrels. The first part about heat treating is actually the first stress relief, not heat treat. Barrel mfgs. buy their steel heat treated to their specs.
Making of a cut rifled barrel.
The Making of a Rifled Barrel, FirearmsID.com

 

[partsproduction]

Butch, I noticed the article didn't mention broaching, is broaching limited to pistol barrels for the most part? I did see a youtube video of pistol barrels being pull broached.
As opposed to keyseat broaching it looks like rifling broaches have 10 times as much swarf area between the cutters, which makes sense since keyseats are normally made in shorter hubs, compared to even pistol barrel length.

 

[Butch Lambert]

My comment was that broaching was cutting the grooves, not button ironing. Mr. Kolbe is cut rifling one groove at a time. I thought the rest of us great unwashed would like to see it.

 

[partsproduction]

Yes, i enjoyed it. And after working on an old lathe I'm unwashed too.

The article didn't mention broaching though, and I wondered if rifle length barrels are broached.

 

[Anthony]

Please specify which cannons? Military artillery barrels are hammer forged, I don't know if they are forged over a rifling mandrel, the day of really large guns has been superseded by missiles.
Do you mean rifled tube liners for reinactor's cannons? I actually spoke with a fellow who uses a single point sine type rifling machine he designed and built for making cannon barrels, but don't know if he is pushing or pulling the tool head.

partsproduction, Ummmm, lets see, the 105mm is broached, the 155 mm is broached, the 175mm is broached, the 8" is broached. Yep these are true to life cannons, not for re-enactors. The 120mm cannon for the Abrams tank is a smoothbore. Been there, done that, and got the t-shirt...

I am not at liberty to tell you more...

 

[Anthony]

Anthony, Pushing a broach is not pushing a button.
A broach cuts and a button irons the rifling.

Butch, I know very well the difference, my post stated " a little off topic ".

 

[partsproduction]

Anthony,
I'm easy to talk with, not antagonistic at all, aware that the internet can make it seem what it's not.

Maybe all the barrels they forge are smoothbore, or maybe they cut rifle them later.
U.S. Army Watervliet Arsenal Rotary Forge Backgound Video - YouTube
I do remember reading that barrel life for most of the larger calibers is, by rifle standards, very short. The Paris gun had a life of 100 rounds IIRC, though they possibly plate the bores or the throats these days.

 

[GGaskill]

The Paris gun had a life of 100 rounds IIRC

and the shells were made in increasing diameters to compensate for the erosion. They had to be fired in sequence.