overview for Skanda

Fully DIY 22lr barrel by Skanda in c/3D2A@fosscad.io

[-] Skanda@fosscad.io 1 points 13 hours ago

Thank you so much for this information. It has always bothered me when metallurgy isn't part of the discussions.

The Dirty Harry is designed for 8 mm liners and has no provision for adding an external sleeve. Fortunately, I can't get barrel liners so will never test it like that. The DH does include a Proto Barrel design which accommodates a 10 mm OD tube which more closely matches the McMaster 3/8 inch tube which I think would be safe.

12 mm OD tubes really do seem to be the most readily available. I'd feel comfortable turning down 12 mm to 10 mm on a lathe, but you're correct, 8 mm seems way too thin. It could be done with a steady rest, but I'd be worried about the pressure.

I'm really not a fan of buttons, I think ECM is much more convenient.

Fully DIY 22lr barrel by Skanda in c/3D2A@fosscad.io

[-] Skanda@fosscad.io 2 points 3 days ago

Ok, thanks. I don't really know how the strength is affected by machining. Metallurgy is kind of a black art to me. I'll have a look at the drilled bolt information. Do you know of they heat-treat anything to improve the strength?

5

Fully DIY 22lr barrel (fosscad.io)

submitted 5 days ago by Skanda@fosscad.io to c/3D2A@fosscad.io

6 comments fedilink

Hello everyone.

I've been following the community for many years and have built a few models thanks to the superb information provided by everyone.

I know this topic keeps coming up especially for non-American makers.

I'm familiar with ECM, I've done the FGC-9 and it turned out very well. I've tried the .22 rifling button from the guy in Ukraine with dubious results (I've NEVER seen rifling buttons on AliExpress). I can see the marks, but I'm not certain they're deep enough. This was for a Harlot build. I then did a .22 barrel for the Dirty Harry build using ECM with mandrels in the Professional Damage ECM Pack. I think that turned out quite well and was surprisingly easy.

I've used 12 mm OD 5.5 mm ID hydraulic pipe from AliExpress which seem to be readily available, but I was trying to find a suitable pipe with a smaller OD.

The best source I've seen is McMaster which carries a 3/8 inch, 0.216" ID which is rated for 15000 psi which seems perfect, but it's like 80 bucks a foot and I haven't even looked at shipping outside America.

I have not found any pipe on AliExpress with a 5.5 mm ID less than 12 mm. I usually look for 42crmo or 'explosion proof' in the description.

I do have access to a small lathe. How safe would it be to turn down 12x5.5 explosion-proof tube to say 8 mm OD for a .22 barrel? Would it support the pressure?

TIA