September 13th, 2020

Neck-Turning Brass with Milling Machine — High-Speed Solution

cartridge brass neck turn neck-turning milling machine Erik Cortina

Here’s the super-speedy way to turn case-necks. Our friend Erik Cortina figured out how to turn his match cartridge case-necks using his milling machine. Erik told us: “While in Raton [a while back], Mid Tompkins told me that he turns his brass on milling machine. He said he could do about 500 in two hours, so I decided to try it.”

Erik fitted a Don Nielson “Pumpkin” neck-turner to the mill, and he used a modified 21st Century case holder to secure the brass. As you can see from this video, Erik was very successful with the process. The tool spins at 1500 rpm, turning Lapua 6.5-284 cases that have been necked up to 7mm.

Video Shows Eric Cortina Neck-Turning Cases with Milling Machine:

Cartridge Brass: Lapua 6.5-284 necked up to 7mm
Lubricant: Lithium grease inside and outside of neck
Neck-Turner: Nielson Pumpkin running at 1500 RPM

It’s hard to argue with Erik’s results. Here are his turned Lapua cases, which have neck-wall thickness consistent to two ten-thousandths of an inch. Think you could do better turning manually?

cartridge brass neck turn neck-turning milling machine Erik Cortina

Some of Erik’s Facebook friends had questions about this process:

Q: Who makes the shell-holder?

Erik Cortina: I did! The shell-holder you can get from 21st Century. I Tig-welded a punch as a handle.

Q: I love the idea of working smarter not harder! Any galling issues? What are your mitigation techniques?

Erik Cortina: No issues. I use lithium grease in spray can. Makes a foam that I dip necks into.

Q: Shouldn’t either the case or the cutter be floating to allow most precise neck turning?

Erik Cortina: Up until [I tried this] I believed the same thing. I was going to build a floating case holder but decided to try rigid setup on a few cases before I built it. Results were great. Neck thickness doesn’t vary more than .0002″, which is same as when I was doing it with floating case holder on the lathe.

Q: Any problems with the Pumpkin changing the cut as it heats up?

Erik Cortina: No — there were no issues with that.

NOTE: Erik Cortina is a very skilled machinist who custom-crafted fittings used for this process. This kind of neck-turning with a milling machine may not be for the everyday hand-loader!

cartridge brass neck turn neck-turning milling machine Erik Cortina

Nielson “Pumpkin” Neck-Turner

The circular orange cutting fixture on Erik’s Milling Machine is a Don Nielson “Pumpkin” neck-turning tool. Don designed this tool to be used by hand or with power. The Pumpkin boasts an eccentric mandrel that allows the cut to be adjusted easily in precise .0001″ increments. Benchresters like this as it allows for very precise control of cut depth and neck-wall thickness.

cartridge brass neck turn neck-turning milling machine Erik Cortina
Nielson Neck Turner with carbide mandrel. Photo Courtesy Butch’s Reloading.

Permalink - Videos, Bullets, Brass, Ammo, Gunsmithing, Reloading, Tech Tip No Comments »
October 7th, 2015

Timney Triggers Made with State-of-the-Art Automated Machinery

Timney Triggers Factory Tom McHale Scottsdale Arizona CNC

For years, Timney triggers have been popular drop-in upgrades for hunting rifles, rimfire rifles, and AR platform rifles. To meet the demand for its many trigger products, Timney Triggers has expanded its operation, adding state-of-the-art CNC machines and other high-end, automated equipment. A far cry from the dank gun factories of the 1950s and 1960s, Timney’s Arizona production center now resembles the squeaky-clean, ultra-modern facilities where electronics are assembled.

Today’s Timney factory is all about computerized automation. Timney Triggers’ owner John Vehr states that it would take 60 or more trained machinists and metal-workers to produce as many triggers as can Timney’s modern machines. Timney does employ two dozen workers, but they are assigned tasks that the computerized machines can’t do as well or better.

If you want to see how Timney triggers are made this days, check out Tom McHale’s recent account of his visit to the Timney Factory in Scottsdale, Arizona. McHale explains how the triggers are designed and fabricated, and 20 high-rez photos illustrate the production process and machinery.

(more…)

Permalink - Articles, Gunsmithing 1 Comment »
August 21st, 2013

New Stiller 2500X Rimfire Action Revealed — Goes on Sale This Fall

Jerry Stiller of Stiller Precision Firearms has revealed the final pre-production versions of his new 2500X rear lock-up rimfire action. Jerry reports: “I have eight of them as prototypes that have been sent to our best smiths to build on and test. As soon as we hear back (in a month or so?), we will start the next run of 100. There will be plenty to go around and should be available this fall for next year’s builds. Cost will be competitive, estimated $1249.00 retail”. Notably, this new action features a convertible 6 o’clock or 12 o’clock firing pin, giving the owner the choice of his preferred configuration. The trigger hanger can also be reversed for a 0.030 change in pin fall.

Stiller 2500X Rimfire smallbore action bolt 22LR

Jerry provided these photos of the first 2500X action off the production line. Jerry notes that: “The only difference with the final production version is that the body will be melonited on the inside for super-slick operation and the outside will still be polished for great looks”.

Stiller 2500X Rimfire smallbore action bolt 22LR

Stiller 2500X Rimfire Action Features

  • Dual rear locking lugs symmetric about the horizontal centerline.
  • Super tight tolerances on all fitted parts.
  • Firing pin design easily unscrews.
  • 6 o’clock or 12 o’clock firing pin. The other pin acts as a guide to eliminate any off-axis canting that can impair ignition and cause flyers.
  • Cocking piece controlled by a shroud so it is always centered in the trigger and cannot rub.
  • Easy loading ramp design similar to the Anschutz.
  • Entrance cams in the body.
  • Beveled loading port
  • Four #8 screw holes for scope mounts, plus two #6 screwholes (in between) also reamed for .125 pins. That way a long one-piece mount or just front-only will both be accommodated.
  • Threaded bolt handle so that any available knob will work. Stiller offers three knob types.

Stiller 2500X Rimfire smallbore action bolt 22LR

State-of-the-Art Machining Technologies Used to Make 2500X Actions
A multi-step process is employed to deliver precision tolerances on every 2500X action. The process begins with a drilled, undersize hole. Then the body is cut and heat-treated/stress-relieved with oversize outside diameter (OD). The Inside diameter hole is wire-EDM finished after heat-treating for optimal sizing and straightness. Next the OD is ground to size and the action face and threads are machined. The action is finally engraved, hand-finished, and melonited on the inside (unless the customer specifies a non-melonited version). Individual parts receive special attention — the extractors are wire-EDM cut, and the bolt lugs are factory-lapped with special devices to load the lugs as they would be when fired.

Stiller 2500X Rimfire smallbore action bolt 22LR

Permalink Gunsmithing, New Product 6 Comments »
November 6th, 2011

5-Axis Milling Magic — You Won’t Believe Your Eyes

In the firearms business we are justifiably proud of the machining quality of high-end components. For example, a multi-flat BAT action with diamond fluted bolt is an impressive piece of machining. But if you want to see a truly amazing example of modern automated machining, watch the two videos below.

BAT Machine

5-Axis Milling Magic
In the videos below, a modern, computer-controlled 5-axis milling machine produces a complete motorcycle helmet shell start to finish. Yes, the motorcycle helmet was milled out of one solid 120kg block of aluminum.

Every feature of the aluminum helmet was cut by machine — even the side vents and rear “50th Anniversary” logo and mesh grill”. The machines in use are 5-Axis hyperMILLs produced by Daishin Seiki Corp. of Japan.

Full-Process Start to Finish
YouTube Preview Image

5-Axis Milling in Real Time
YouTube Preview Image

Permalink - Videos, Gunsmithing 3 Comments »
October 17th, 2009

Greatest Hits: Machining Art from John Loh

LINK: John Loh Rest Donated for World BR Championships
Can a rest be a work of art? Yes, it can — when crafted by John Loh of JJ Industries. John, one of the great guys in the sport, donated this rest to support the U.S. Team at the BR Worlds in South Africa.

Permalink Gear Review No Comments »