"Louis Ohland" wrote in message
...

Before building a single-shot rifle, anyone should read deHaas's books.
He's
the expert. His son has one or more books out, too. I haven't read them
but
his dad knows his stuff, so they're probably good. DeHaas also is an
experienced critic of the common single-shot actions, and a designer of
several well-regarded ones himself. I'd stick to one of his designs or
make
a straight replica of a Winchester Hi-Wall.


I have at least three of DeHaas' books. My dad got wired up on this Bill
Holmes design.

The significant question is how do you machine the passage for the block
so it's got somewhat square corners? Or is a slight radius OK? I see the
square broaches, but isn't an acutely square corner a good place for a
crack to start?

FWIW, my 1885 Browning (ne. Winchester Hi-Wall), which I no longer own, had
radii of around 1/32" or maybe slightly more in the corners. My Farquharsen
replica is about the same.

I don't have Frank's books anymore (I loaned them out and never got them
back), but didn't he address that issue somewhere?


One approach would be to drill four holes at the corners of the block
passage, broach them square, then use a hole saw for gross metal removal,
followed by a 1/2" mill to square up the sides. Is there a less manly-man
way of doing it?

Before someone mentions casting, that is not an option.

Bandsawing is one way it's done. There was a woman on the Outdoors Forum of
CompuServe a couple of decades ago, an aerospace engineer, who made
falling-block actions by drilling a start hole, bandawing the rectangle, and
then finishing with a shaper. She made her actions out of 17-4
precipitation-hardening stainless.

Another guy I know bought my desktop shaper from me specifically for making
single-shot actions. I'd start with wirecut EDM, leaving about 0.005" on
each side, and finish with a shaper and lapping.

--
Ed Huntress


For those up on DeHaas, look at the Chicopee RF. Problems: 3/16 CRS plates
welded or silver soldered to barrel area. I like the swinging block, but
I'm not sure it would do well with the 5mm. Look at the Chicopee CF
action, and the bolt locking arrangement goes from a milled shaft (RF) to
sort of a rolling block design (CF).