The 32 ACP Revisited
-Ed Harris
© 2014
I've
reloaded for the .32 ACP for over thirty years. These pocket guns don't have
any great reputation for accuracy. The Speer No. 13 handbook states that
3-4" groups at 25 yards are the best you can hope for. This agrees with my
experience. WWII German military and postwar German police acceptance accuracy
standards which allowed 5 mils or 75mm of dispersion (about 3") at 15
meters (approximately 49 ft.). My Beretta Model 3031 Tomcat barely does this
with good ammo when I do everything right. Typical 25-yard eight-shot groups
are more like six inches. More traditional Full-sized .32 pocket pistols do
much better and are more useful as field guns for small game within 50 feet or
so.
Any pocket
pistol which groups better than 4 mils, or 60mm (2.36") at 15 meters is
said by Europeans to be quite good. My experience with a dozen .32 ACP pistols
over the years suggests the most accurate pocket pistols are the Walther PP
(not the PPK - it little better than the mouseguns), FN M1922, Mauser HSc,
Beretta M70, Colt Pocket and CZ27. Any of these reliably group about 2-1/2” at
50 feet, with good ammo. The best .32 Automatics using tweaked handloads can do
about 2 inches at 50 feet over a series of groups without excluding any
"called shots" or fliers, but accepting all the data as it comes. Any
pocket pistol which does so should be considered a “keeper.” This is reality.
Testing,
WWII-era .32 autos in my collection, typical results are 4 inch group averages
in series of five consecutive 8-shot groups at 25 yards, firing full magazines
off sandbags with European CIP specification RWS, Privi Partisan, Sellier &
Bellot or Fioccho Ball ammo. This compares to what typical 2-inch .38 Special
snubbies do for five or six shots off sandbags at the same range with +P service
ammo, a good benchmark. The limiting factor in accuracy of small handguns is
short sight radius.
A personal
defense gun will most likely to be used from near-contact distance to no more
than 10 meters. Sight radius is less important because the recommended
technique in close quarter defense situations is "target focused"
maintaining situational awareness, watching the bad guy's hands, moving to
cover, etc., rather than being "sight focused," as it tends to be
when engaging targets beyond ten meters, such as the grouse or rabbit you want
to eat.
My favorite
cast bullet handloads in .32 ACP use either the 98-grain Saeco #325
semi-wadcutter, Meister 94-gr. .312 flatnose or the 88-gr. NEI #82
flatnose. If you do not cast your own
bullets, just buy the Meisters, load 1.7 grains of Bullseye and seat bullets to
0.95-0.97" overall cartridge length.
If you cast your own, use wheelweights, tumble-lubricate the as-cast
bullets with Lee Liquid Alox, and load them as-cast and unsized with 1.7 to 1.8
grain of Bullseye. The Saeco #325 bullet
can be crimped in the normal revolver crimp groove. Do not load the NEI or
Meister bullets shorter than 0.95 inch.
I taper crimp using a custom Lee Factory Crimp Die which has a carbide
full length sizer. This removes any bulges caused by mis-match of bullet
diameter with case wall taper, profiles
the loaded rounds for easy chambering and sizes the bullet, if needed by
compression inside the case. A custom Lee Factory Crimp Die (FCD) costs $30. I
highly recommend one for anyone who is serious about reloading for the .32 ACP.
Using the
88-grain NEI #82 bullets 2 grains of Bullseye is a full charge load which
should not be exceeded. Do not exceed
1.8 grains of Bullseye with cast bullets over 90 grains.
A lot of
misunderstanding is caused by inaccurate mythology and folklore in old Lyman
manuals which recommends sizing cast bullets to the groove diameter of the
barrel. This results in undersized bullets not fitting the forcing cone or
throat and being gas-cut, causing leading at the origin of rifling and poor
grouping.
The
recommended practice for lead bullet ammunition in the firearms industry is
that lead bullets be of a diameter to enter the throat or forcing cone without
resistance, but to fit as closely as possible so that the bullet upsets to form
a positive gas seal instantly upon discharge. The ideal condition is for bullet
alloy hardness to be matched to working chamber pressure, and for the bullet to
be not smaller than 0.0005 under throat size.
Typical
wartime European pistols vary all over the map with respect to barrel bore and
groove dimensions, twist rate and chamber dimensions. Colts, Berettas and
Walthers have 16 inch twist, FNs, CZs and Mausers have 10 inch twists.
FN, Mauser
and Walther pistols in my collection typically have groove diameters of
.307-.309, Berettas, CZs and Colts run .310-.312. I have not seen chamber
throats smaller than .311, but have seen WWI and WWII era Spanish, French and
Italian pistols as with throats as large as .316. This wide variation in bore
sizes coupled with factory jacketed bullet diameters from .308 to .312 explains
a lot of the accuracy problems people experience with the .32 ACP.
In my
experience European Sellier & Bellot, Sako, Lapua, and RWS ammo having the
smaller bullet diameter works best in Walthers, Mausers, MABs and FNs, while
larger Privi-Partisan, Fiocchi and handload using Magtech, Remington Hornady
and Speer jacketed bullets are more accurate in Kel Tec, Beretta, Colt, Astra,
Unique, Star, Llama and CZ.
My 1935
Beretta wartime pistol had an oversized .315 throat with .313 groove diameter
barrel and produced six inch-plus groups at 25 yards with its original WWII
salt and pepper barrel. After fitting a new barrel machined from a 14 inch
twist Hart .308 blank with minimum CIP chamber and .312 throat set up to
headspace on the case mouth groups shrunk to 3 inches at 25 yards with good
ammo, using iron sights.
I had two
custom barrels made to fit a Beretta European target pistol chambered in .32
ACP, of nominal .300 bore and 308 groove dimensions, with 10 inch and 14 inch
twist barrels, respectively, chambered with the same reamer. Firing off sandbags with a 4X Leupold scope
the target pistol would shoot an inch at 25 yards with the best hardball ammo,
and 1-1/2 inches with my cast bullet handloads. Don't ask what it costs to
machine a chunk of Hart barrel and have custom chambering reamers and
headspaces gages ground. If you need to ask, you cannot afford it. Figure seven hours of machine time, plus the
cost of barrel blanks and tooling. Ahh...what we do for science~!
European CIP
throat dimensions specify 7.9 + .05mm - 0.0 mm. or .311-.313", so for most
pistols a .313 bullet is correct, but some wartime pistols may need .314
bullets, if they will chamber safely without resistance. If your chamber is
tight, but the throat is large, good results can be obtained by loading the
bullet as-cast and unsized, leaving a portion of the driving shoulder exposed
ahead of the case mouth to fill the throat, and using a custom Lee Factory
Crimp die to profile the loaded rounds to within max. cartridge dimensions,
eliminating any case bulges caused by mis-match of bullet diameter to internal
case wall taper.
A good
approximation of proper alloy hardness is estimated using the rule 3(BHN)x480 =
working pressure.
US .32 ACP
ammunition is loaded to a maximum product average of 16,000 psi. Solving for
BHN we get: 3(480) / 16,000 = 11 BHN, which works well for mild loads which are
at the minimum for reliable functioning.
European
ammunition loaded under CIP may reach 20,500 psi. My wartime Beretta, FN and CZ
pistols steadfastly refuse to function with anemic US ammo, so hotter loads
needed to function reliably require harder alloy:
3(480) / 20,500 = 14 BHN
I load 88-98
gr. cast bullets in the .32 ACP all the time. The store-bought solution is the
Meister 94-gr. flatnosed .312 diameter bulk bullets with 1.7 to 1.8 grains of
Alliant Bullseye, the charge varied depending upon case weight. RWS and Fiocchi brass weigh 40 +/- 1 grain
and get the lighter charge. Remington brass weighs 36 +/- grains and gets the
heavier charge. Either load gives about 750 f.p.s. in a 10cm barrel such as the
Walther PP or FN M1922 Browning. In guns
which feeds SWCs, I use the 98-gr. Saeco #325 with 1.7 grains of Bullseye, and
crimp in the normal revolver crimp groove. Its large flat nose is very
effective on small game.
Do not shoot
a lot of heavy bullet loads in .32 ACPs having light aluminum alloy frames,
because they are harder on the gun. They work best in steel-framed European
guns which are balanced for heavier bullet 73-74-gr. ammo. My WWII-era pistols
don't function at all well with typical US 71-gr. commercial ammo or 60-gr,
JHPs.
In my
chronograph testing Remington, Winchester, Federal and Magtech 71-gr. FMJ ammo
average only about 850 f.p.s. from a full sized pistol such as the Walther PP,
Beretta M70 or FN M1922. CIP specification 73-gr. ammo such as RWS, Geco,
Fiocchi or Sellier & Bellot goes 900-950 f.p.s. American 60-gr. JHPs
typically give about 900 f.p.s. but because of their light bullet, may not have
enough recoil impulse to reliably operate older European pistols.