Electro Chemical Machined rifling

[Bob Wright]

Back in the 70's and 80's we machined a variety of gas turbine blisks, compressor blisks and related parts using this ECM process. Since we had a lot of heavy metal sludge like cobalt, we abandoned the process due to environmental issues.
Surprising to see a new barrel company in England utilizing this old specialized technology.
'Pendragon Precision' (on Facebook).
Apparently the barrel bore and rifling is carefully choked all the way to the muzzle.
The process is essentially de-plating to make a form, in this case, rifling. Using graphite form tools and pumping electrolyte thru the barrel and around the electrically charged metal and the process ends up being a non-contact machining process, similar to EDM. No imparted stress to rifle the barrel.
Just need plenty of amps and some good engineering.

 

[GrayCreed]

Tagging in I'm interested in this

 

[Rich Coyle]

Sounds great. I'm interested too.

 

[Bob Wright]

Apparently in Beta Phase. They are getting these out to a dedicated group of shooters to test and feedback. Cool but old technology being used for a new purpose.

 

[Bob Wright]

For an explanation of the process:

Electrochemical machining - Wikipedia

en.m.wikipedia.org

 

[Tiny Tim]

It was used to great effect and tolerances were typically true. Exposed to it in the aerospace industry. Since there is no mechanical stress induced, the relief of drilling the hole should result in a remarkably stable blank as long as the exterior contour is done first. Interested in seeing where this goes, if anywhere.

 

[acg333]

hope this will be much cheaper than cut rifling.

 

[epoletna]

Following.

 

[HRM Johnny]

Tag

 

[sable tireur]

The ECM process was used decades ago for making those larger deck guns for the Navy and field guns for the Army. It was an expedient method since the machining steps and the process time were reduced.

https://apps.dtic.mil/sti/pdfs/ADA072437.pdf

https://bernardandcompany.com/ecm-new-paths-in-part-production/

 

[HRM Johnny]

Thanks @sable tireur

 

[Taylorbok]

hope this will be much cheaper than cut rifling.

IMO cut rifling isn't that expensive considering the process.

 

[Iron Worker]

I'm interested

 

[Buck Fever]

It's interesting that they mention value, I wouldn't expect a barrel made that way to be cheap. Every caliber and every twist needs a different electrode and I think they are somewhat consumable. I know the machines are expensive and I believe the process is slow...