Shooting the Vetterli
by
"Parashooter"
By the time I had spent three hours at a Massachusetts
gun show, I was about ready to give up when a curly triggerguard attached to a
dirty old rifle caught my eye. Ten minutes later I was on my way home with an
1878 Vetterli. Once the accumulated dirt and dust came off, I found I had as
pristine a specimen as I've seen outside a museum.
Now what? I'm a shooter - not a pure
collector. First I went to find the websites on centerfire conversion. The
methods described seemed like more modification than I like to make on a
classic like the M1878. I knew I was going to have to make a hole in the bolt
face, but I didn't like the idea of drilling the striker or grinding up the
original firing pin (even after I found a spare under the buttplate).
It appeared to me that a centerfire firing pin on the same principle as the
rimfire pin(s) might work. I grabbed an old Volkswagen bolt and started
drilling, grinding and filing. Two hours later I had a firing pin that would
slip into the new hole in the bolt and was long enough to be retained by the
striker in the same way as the rimfire pin was.
Here's the rimfire pin, the centerfire pin, striker, and bolt.
Now I needed some ammunition. I'd heard 45/70 would work, but the information
on the web suggested .348 Winchester brass. OK, I had 10 new .348 cases lying
around from making Lebel rounds.
Everything I saw suggested expensive custom loading dies. No thanks! This
rifle's bore measures .430" - same as .44 S&W Russian/Special/Magnum.
I ran a .348 case into a .44 Mag sizer die until a second shoulder was
formed where it needs to be to fit into the Vetterli chamber.
The .348 cases were just a little too snug in the chamber and needed to have
about .002" filed off the base 1/4" forward of the rim. This was
easily done by hand with a little safe-edge file (Swiss, of course).
Then I sawed off the .348 a little longer than 38mm, put a .425 pilot in the
trimmer and cut the new ".44" neck to give a length of 1.55".
After deburring, .430" bullets were a good fit, no expander needed.
1. .348 Winchester partially sized in .44 die.
2. Trimmed, filed, fireformed case (and scrap).
3. Loaded round with .430" semi-wadcutter.
4. Fireformed round made from 45/70 - too ugly even for me!
This all turned out much easier than I expected - and a whole lot cheaper than
those custom dies. I fired ten loads with the 250 grain SWC and 12 grains of
Unique and grouped about 4" at 50 yards - and 20" above point of aim.
(The lowest setting on the 1878 sights is 225 meters.) Later I reloaded the 10
cases with 13.5 grains Unique - no sizing needed - and clocked them at 1450
fps.
I needed a mould for a longer bullet to be able to use the magazine, OAL
being critical to the Vetterli's "primitive" feed mechanism.
Eventually I designed a modernized copy of the Swiss 1871 bullet design and
had a custom mould made that has worked very well, even helping me to
a silver medal at the First Annual Springfield/Military Bolt Rifle Match held
at Camp Perry. For magazine use, bullets should be firmly crimped.
Here are details of the centerfire conversion.
First thing is to drill the bolt. A little off-center is OK but not more that
.010" or so. Best is to drill from the back end of the bolt with drill
mounted in a long rod shaped like the Vetterli striker but this is a lot of
work and I'm lazy.
The other choice is to drill from the front. First rig up a small center punch
to fit in a deprimed case that fits the rifle. Center it with masking tape
wrapped around or whatever. Chamber this rig. Close the bolt. Give the punch a
light rap with a rod inserted from the muzzle. If your punch is good, you'll
have a neatly centered dimple to start your drill. (Don't pick a case with an
offset flash-hole!)
Put the stripped bolt in a drill-press vise, make sure everything's square and
drill through with a high-speed bit. I used .085" but bigger up to about
.10 would be OK. I've noticed most original blackpowder cartridge rifles have
BIG firing pins, like shotguns still do.
The Vetterli bolt is easy to drill with a good steel bit. Some cutting oil and
a slow speed helps keep cool. Stone off any burrs on the bolt face around the
hole but don't chamfer or take any material off the face.
The pin itself is a job! (But see more below for an easier way.) I started off
with an automotive bolt with about an inch of unthreaded shank, cut the head
and threads off leaving a piece of 3/8" steel rod about an inch long. Any
tough steel rod that size would work fine. Whatever you use has to be soft
enough to drill but hard enough to make a strong pin. Auto bolts for engine and
suspension applications are usually pretty good stuff and easy to find.
Next step was to drill a hole in one end of the rod that will be a slip fit for
the end of the striker. My striker measures about .180" and I drilled
.185". Drill to about 3/8" deep. If you can, drill or mill the bottom
of the hole flat. Use the rimfire striker as a model.
Now chuck the drilled end of the rod in a lathe. No lathe? Me neither, I
chucked it in a portable drill and spun it against a bench grinder (fine grit
wheel). Turn, file or grind the undrilled end of the rod down until it is a
slip fit in the firing pin hole drilled in the bolt. This pin end should be
about 4/10" long. Round the end as smoothly as possible.
Then you take this now 2-diameter rod and grind or file the big end flat,
taking equal amounts off opposite sides until the flats break through to the
drilled hole and the thickness is a slip fit in the slot in the bolt (about
.170").
The result is a "Y" shaped part an inch long. Looking at the rear end
of the rimfire pin gives an idea how to grind/file a compound radius on the
back to enable the pin to just enter the back end of the drilled hole in the
bolt while the flat part of the piece slips into the slot.
That slot is about .850" long. My finished piece is .870" long - just
enough to keep it from having both ends free at the same time. As long as the
striker rod is in assembled position, it can't fall out.
By removing material from the back of the piece, it will eventually be able to
"tip" into the slot after placing the rounded end of the pin into the
pin hole in the bolt.
Now slip the striker into the bolt and push it all the way forward. Unless,
like me, you drilled the hole in the back of your new firing pin too deep, you
will now be able to adjust the pin protrusion by drilling that hole a little
deeper (.050" protrusion seems about right for the Vetterli.)
Note that the wide flat part of the new piece doesn't contact the front of the
slot. The pin is intended to "float" and will hit only the primer. I
don't dry-fire mine but let the striker down gently by closing the bolt on an
empty chamber with the trigger pulled or by using a fired case as a "snap
cap".
Because I didn't drill that .185" hole with a flat-end bit, the conical
end of the hole peened a bit deeper after about 10 shots and I lost sufficient
protrusion to fire. I corrected this by flattening a .177" cal. steel BB
enough to be a drive fit in the hole, dressing it down to a .030" thick
wafer and driving it to the bottom of the hole.
Here are some pictures that might help.
1. Close-up of the finished pin, looking slightly from the back but mostly from
the side. The BB is fairly evident, as is a chamfer at the back of the
.185" hole that helps when assembling the striker.
2. Looking into the back end, down the .185" hole.
3. The complete piece in position with the pin through the bolt face and the
striker resting in the .185" hole.
I'm sure it would be much easier to drill the end of the striker rod and
silver-solder in a pin. I just didn't want to do anything non-reversible. (That
hole in the bolt face is easy to fill by tapping it part way for a screw which
is then turned tight into the hole and dressed flush - just in case someone
decides to start selling fresh .41 Swiss rimfire ammo down at the corner
gunshop!)
Later I found an easier way to make the centerfire pin - as an assembly
instead of one piece.
Drill the hole in the bolt face somewhere between .072" and .080".
(Depends on what drills you have - #49 is .073", 5/64" is .0781"
).
Instead of starting with a 1" long rod and turning half of it down to make
a pin, start with a .6" long rod. Drill the .185" hole to a depth of
.45". Don't bother with a flat-ended bit. Take the .185" bit out of
the chuck and replace with a .069" bit. Drill right through with this bit.
(This is somewhere between a #51 and a #50 bit - not really critical.)
(You could also use 1/4" flat stock instead of a round rod and save some
work flattening it. Material quality is less critical now since there will be
little stress on this part. It's just a holder for the separate pin.)
Dress the rod flat, as described previously, to a thickness of .175" or a
slip fit in the bolt's slot. Grind/file a radius on each end of the part,
leaving it .560" long.
Take an RCBS "headed" decapping pin (which measures .069" on the
shank and .14" on the head) and shorten the small end until the pin
measures about .580" overall. Make a nice rounded end and drive it through
the .069" hole at the bottom of the .185" hole. Stake the pin in with
a rounded 1/8" punch on both flats.
Now grind the compound radius clearance bevel on one side of the back end of
the "pin holder", tip the firing pin assembly into the bolt, put the
bolt handle on the bolt in the "fire" position and insert the striker
all the way forward. Adjust the pin protrusion to .050" by trimming and
rounding the tip of the pin.
This takes about 1/4 the time compared to making the pin in one piece. The
decapping pins are cheap and can be replaced easily by driving and staking in a
new one.
Warning:
In experimenting with various centerfire firing pin configurations, I was
able to create a hazardous condition that should be avoided.
If making a centerfire pin assembly as described above, be sure there
is no condition under which the assembly can wedge against the cocked striker
with the pin protruding from the bolt face. Such a condition could result in
firing out-of-battery.
This condition can be easily avoided by making sure the completed
assembly is no more than 0.90" long AND that with the striker in cocked
position there is clearance between the flat end of striker and the centerfire
pin assembly when the front of the pin is positioned flush with the bolt face.
If you're not sure about avoiding this hazard, please try one of the other
conversion methods described elsewhere.
The point where clearance is essential is indicated below:
Additional insurance is to cut a significant chamfer at the back of the
assembly where the striker enters and to make sure the flat end of the striker
has a nice smooth rounded edge.