ECM rifling method discussed

[JFrank]

A friend of mine sent me this link as something he thought notable , I’d like to share with the members of AS and hear some additional thoughts.

Jim

 

[GotRDid]

Very interesting! Thank You for the introduction to this tech.

 

[xr650rRider]

Not new, maybe improved? Don't think early efforts went too well.

This was from 2015
https://www.merlinmachinery.com/why-merlin-machinery/

I knew I had read an older thread on the process.
https://forum.accurateshooter.com/threads/ecm-barrels.4073785/

 

[charlie b]

Worked with edm in the early years. I liked it then so this looks like a good application for it. The advances in using the special shape tooling have advanced tremendously.

 

[GotRDid]

Not new, maybe improved? Don't think early efforts went too well.

This was from 2015
https://www.merlinmachinery.com/why-merlin-machinery/

Could be lack of capital, insufficient exposure to the very demographic that was the target audience, or perhaps stumbling blocks that impeded progress. Of course, then there was the c19 shutdown that bankrupted many businesses.

 

[Davester]

Could be lack of capital, insufficient exposure to the very demographic that was the target audience, or perhaps stumbling blocks that impeded progress. Of course, then there was the c19 shutdown that bankrupted many businesses.

No, while it took a little while to perfect the process Pendragon Precision made their first ECM barrel in 2015. Since then Pendragon ECM barrels have received fantastic reviews and feedback from many users who report increased velocities, ease of cleaning, better accuracy and longer durability than cut or buttoned barrels. The company is very much alive. Merlin Machinery was formed in 2024 to market the Pendragon technology to OEMs and other barrel manufacturers

 

[clowdis]

I have to be a little skeptical. Electrodes do wear and to keep one perfect dimensionally through 28 inches of steel seems like too much to ask. Also I've never seen a finish from an EDM machine that would equal the finish left by a button. I don't see this process replacing button or cut barrels any time soon.

 

[moondog]

Technology moves ahead. Looks interesting for sure. 3D Printed suppressors? Who would have guessed those would be main stream now.

 

[Davester]

I have to be a little skeptical. Electrodes do wear and to keep one perfect dimensionally through 28 inches of steel seems like too much to ask. Also I've never seen a finish from an EDM machine that would equal the finish left by a button. I don't see this process replacing button or cut barrels any time soon.

EDM and ECM are very different. Electrode wear is minimal and limited to any insulating material on the electrode caused by friction with the barrel - very minor. Surface finishes are excellent 0.2 Ra um or better. ECM rifling is the future

 

[9146gt]

S&W have used ECM barrels for years>
Tom

 

[xr650rRider]

Supposedly Desert Precision Gunworks has their own ECM machines and are producing .22 rimfire blanks for their rifles.

https://www.snipershide.com/shootin...ed-new-rimfire-action…….7253710/post-12101109

 

[Davester]

S&W have used ECM barrels for years>
Tom

Indeed they have, no where near as difficult to manufacture due to the very different aspect ratio to rifle barrels and the lower tolerance requirements. We are unaware of any other manufacturer producing a successful commercial match rifle barrel with ECM prior to 2015.

 

[JFrank]

I wouldn’t expect to see the long time traditional barrel makers investing towards retooling anytime soon however McGowen certainty has taken that step.
What I find intriguing is the precision in which the rifling barrel can be created.
The friend that sent this link to me uses McGowen quite often now and will likely try one of the ECM, I’ll be anxious to look at one through a borescope as well as a price sheet.

 

[jelenko]

Google's AI description of how dimensions are held with ECM [Even with this description, I don't understand

Dimensions in Electrochemical Machining (ECM) are held by using a shaped cathode tool that acts as a negative, non-contact mirror image of the desired part, maintaining a precise interelectrode gap (IEG) typically ranging from 80–800 micrometers
. Because material is removed at an atomic level through electrolytic dissolution without tool wear or mechanical stress, high accuracy and repeatability are achieved by managing the gap distance and tool feed rate.
Here is how dimensions are specifically controlled in ECM:

• Equilibrium Gap Management: The tool advances toward the workpiece at a constant rate, while the electrolyte flows between them. An equilibrium gap is established where the anodic dissolution rate equals the tool feed rate, ensuring the workpiece takes the exact shape of the tool.
• Precise Tool Design (Cathode): The tool is designed to be the reverse shape of the final part. Because there is no tool wear, the same tool can produce identical parts repeatedly.
• Electrolyte Flow and Temperature Control: A pressurized electrolyte is passed through the gap to remove metal hydroxide sludge and dissipate heat. Controlling the flow rate, pressure, and temperature of the electrolyte is critical for maintaining consistent material removal rates across the surface.
• Process Parameter Optimization: Dimensional accuracy is maintained by strictly controlling parameters such as voltage (3-30V), feed rate, pulse length, and electrolyte concentration.
• Tool Insulation: In specific applications (like micro-ECM), the sides of the tool are insulated to restrict electrical discharge to the tip only, which prevents stray cutting and improves dimensional accuracy.
• Voltage Pulsing (PECM): Pulse Electrochemical Machining (PECM) uses high-frequency, short-duration pulses rather than continuous current to improve localization of the dissolution, leading to higher precision and tighter tolerances.

 

[GotRDid]

I appreciate the input and clarification of this process, and tech.
Forum Participants here help me in getting “Smarter every day”.

 

[jelenko]

I appreciate the input and clarification of this process, and tech.
Forum Participants here help me in getting “Smarter every day”.

So do I.

 

[Fast14riot]

Think of ECM as reverse electroplating. The "wear" is what was machined in the end, not the tool. Its just a highly controlled process, but principle is the same.

 

[xr650rRider]

Controlled form of electrochemical etching.

 

[Alex Wheeler]

Im excited to chamber some

 

[Xerothermic]

Cost? For the average Joe-blow.