On Thursday, September 12, 2013 6:14:49 PM UTC-4, wrote:
On Wednesday, September 11, 2013 10:28:06 AM UTC-6, PCS wrote:
T'all, A few years ago I made a new barrel for an old German-made Hubertus .177 caliber air pistol. Quite by accident, it came out pretty well: https://plus.google.com/photos/11723...88823271886433 Since then I've probably plinked a thousand pellets thru it. Loads of fun for the G'kids. At the time, I briefly looked for info on rifling such a small barrel, but found little available at this size. My general understanding of the process is that a hardened button is pressed through a barrel to rifle it. I've never done this type of thing myself though. I'm currently toying with the idea of making another barrel, as I've still plenty of the 20mm O1 steel I bought for the first barrel, but this time I'd like to see about rifling it. Does anyone have any information on how I might go about making another rifled barrel for this caliber air gun? Thanks, -- PaulS
There's not a lot of books out there on how-to for barrelmaking, I've got one that's basically an unedited manuscript I bought off of a custom maker years back that details everything needed to go into button rifling. Howe's "The Modern Gunsmith" tells how to set up a barrel drilling operation complete with gundrills and scrape or hook rifling heads. It'd be far cheaper to buy a target barrel spare from an air rifle supplier and cut and turn it to size than set up for a onesie rifling project. The button rifling guy pulled his buttons rather than psuhing them, took a fairly healthy hydraulic rig. Just making the buttons took a fancy cutter grinder and diamond wheels as well as a premium grade of carbide. It's a production method for hundreds of barrels rather than being suited to a one-off. A sine-bar scrape- or hook-rifling setup is far more suited to one-offs. The grade of steel makes a huge difference on how good a job of rifling you get with the buttons.
Stan
Hi,
Yes, for air-gun barrels any free machining steel is best, no need for CrMo..
So, with carbide buttons currently out of reach economically, I'm looking for a cut rifling solution then.
Even if I did want to hack together an indexing sine-bar machine, the design and construction of a .17-size single-point, adjustable, cutter assembly has me a bit stumped so far. If anyone is doing cut rifling at this size I'd love to hear all about it.
I have however heard far away tales of a spiral-fluted reamer being successfully brought to this task.
With 6-flutes, and a respectable twist rate, it has some merits as the starting point for a small scratcher tool.
The idea, as far as I've heard, is to grind a broaching profile to cut all the rifling in one pass, using the ream's spiral fluting to provide the twist of the cutting action in the barrel. Sounds too good to be true.
I'll keep looking into it though.
Thanks for your thoughts.
--
PaulS