Loading the .32 ACP


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Ed Harris
October 6, 2009, 09:50 AM
I've reloaded for the .32 ACP for over thirty years. The limiting factor in accuracy of these small handguns is their short sight radius. A personal defense gun is most likely to be used from near-contact distance to no more than about 20 feet. Sight radius is therefore less important because the recommended technique in close quarters combat situations is "target focussed" instinctive point shooting, maintaining situational awareness, watching the bad guy's hands, moving to cover, etc., rather than being "sight focussed," as is necessary when engaging the sitting grouse or rabbit 20 to 50 feet away that you want to eat. This article pretty much sums up the rationale for the .32 ACP http://shilohtv.com/?p=2720

My favorite cast bullet handloads in .32 ACP use the 88-grain NEI #82, the 98-grain Saeco #325 semi-wadcutter or a 93-grain hollowpoint modification of Saeco #325 by http://www.hollowpointmold.com/. You could also use the RCBS 32-90CM with these loads for similar results.

If you dont cast your own bullets, you can buy the 94-gr. .312 flatnose cowboy bullets from Meister and they will work just fine. I cast my own bullets from wheelweights, tumble-lubricate them in Lee Liquid Alox, and load them as-cast and unsized with 1.7 to 1.8 grains of Bullseye. The Saeco #325 is crimped in its normal revolver crimp groove. Do not load the Meister or NEI bullets shorter than 0.95 inch overall, because excessive intrusion of the shank of the bullet into the powder space raises pressure dramatically. It is also necessary because of their flat nose profile and larger meplat, not to exceed 0.975 inch overall cartridge length to prevent bullet noses from dragging against the front of the magazine box.

I taper crimp using a custom-made Lee Factory Crimp Die for .32 ACP. This has a carbide full length sizer which removes any bulges caused by mis-match of the bullet diameter with the internal case wall taper, ensuring easy chambering and sizing the bullet, if needed by compression inside the case. A custom Lee FCD costs $30. I highly recommend one for anyone who is serious about reloading for the .32 ACP.

Alot 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. Recommended practice for assembly of lead bullet ammunition in the firearms industry is that bullets be of diameter to enter the barrel forcing cone without resistance, but to fit as closely as possible so that the bullet upsets instantly upon discarge to form a positive gas seal, prevent gas cutting.

Excessively hard, undersized commercial cast bullets are more likely to cause leading than softer ones of correct diameter. 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 inch less than chamber throat size. Maximum suitable chamber pressure for a given caast bullet hardness is estiminated by multiplying its Brinell Hardness Number times the constant 1440. For instance wheelweight alloy when slowly air cooled after casting has an average BHN of 12, so to estimate a correct working chamber pressure 12x(1440) = 17,280 psi. This is a good match for standard .38 Special or .32 ACP ammunition which has a maximum average chamber pressure of about 16,000 psi.

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 have groove diameters from .307-.309, Berettas, CZs and Colts run from .310-.312. I have not seen chamber throats in any .32 ACP pistol smaller than .311, but I have seen WWI and WWII era Spanish, French and and Italian pistols as with throats as large as .316. This wide variation in bore sizes coupled with factory jacketed bullet diameters which vary in different makes of ammunition and component bullets from .308 to .312 explains most 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 handloads using .311-.312 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 custom machined from a 14 inch twist Hart .308 blank with minimum CIP chamber body and .312 forcing cone diameter set up to headspace on the case mouth, groups shrunk to 3 inches at 25 yards with good handloads, using iron sights. A custom Beretta target pistol with 6 inch Douglas barrel and 4X Leupold scope shoots FMJ ball ammo in to a little over an inch at 25 yards and cast bullet handloads just as well.

For those who would ask "why?" I did it because "I could, and I wanted to know."

Do not shoot multiple thousands of cast bullet loads with bullets heavier than 90 grains in the "mouse guns" having light alloy frames, because their increased recoil impulse is harder on the gun. The Beretta 3032 INOX pistol has a heavier slide than the original Tomcat which reduces slide velocity to mitigate against this problem. My INOX has proven more rugged than the original Tomcat and has digested over 2000 of these loads and hot RWS hardball with no issues.

In my chronograph testing Remington, Winchester, Federal and Magtech 71-gr. FMJ ammo average only about 850 f.p.s. when fired from a "full sized" .32 pistol such as the Walther PP, Beretta M70 or FN M1922. CIP specificiation 73-gr. ammo such as RWS, Geco, Fiocchi or Sellier & Bellot does 900-950 f.p.s. TypicalUS make 60-gr. JHPs typically are about 900 f.p.s. but because of their lighter bullets, do not provide enough recoil impulse to reliably cycle the older European pistols.

The heavy bullet .32 ACP loads discussed here approximate the velocity of .32S&W Long ammo fired from a 4-inch revolver. Its recoil impulse is similar to European CIP specification 73-74-gr. hardball ammo. WWII-era pistols don't function at all well with typical US 71-gr. commercial ammo or the popular 60-grain JHPs, but these cast bullet loads are accurate, are great for recreational shooting or small game and run the wartime guns like a pony trotting .

Because I may carry either a .32 S&W Long revolver or .32 ACP pocket pistol around our country place, I wanted the option to use these ammos as small game rifle rounds. I searched the Internet and found nothing about anyone trying the .32s in a rifle. I felt that for a "walking gun" I would have two barrels made to fit a tiny pre-war H&R .410 shotgun, converting it to a 4 lb. American Rook Rifle of sorts. My reasoning was that for very light, quiet “.30 cal. CB cap” loads, approximating the .32 rimfire, the tiny .32 ACP case would have advantages, whereas the larger .32 S&W Long case would have more capacity if I wanted something closer to .32-20 energy. I opted for an 18” barrel for the .32 ACP as a backpack takedown rig and and a longer 26” one for the .32 S&W Long to ensure “maximum quiiiieett so as not to scare the bunny wabbits!” Getting inch groups at 25 yards with iron sights proved challenging for old eyes, but I managed to do so with enough different loads to prove it highly practical. Winchester .32 S&W Long 98-grain LRN, and .32 ACP Fiocchi and RWS 73-gr. hardball averaged just under an inch groups at 25 yards. Cast bullets did as well or better.

Fired from a rifle these tiny handgun rounds are subsonic, quiet and accurate. Factory , 98-gr. LRN loads from the .32 S&W Long rifle with 26 inch barrel gave 884 f.p.s. From the 18 inch .32 ACP, Fiocchi 73-grain hardball clocked 943 f.p.s., and RWS hardball 1214 f.p.s. and Fiocchi 60-grain JHPs screamed at 1463 f.p.s.~! My original goal was not high velocity, but subsonic, quiet small game loads approximating the ballistics of a .32 Long rim fire (from .32 ACP brass) or standard velocity lead .32-20 loads (from .32 S&W Long brass). These objectives were met handily.

Velocities of my normal .32 ACP cast bullet loads with 1.7 to 1.8 grains of Bullseye fired from the rifle are about 900 f.p.s. and they shoot inch groups at 25 yards. I don’t view this as a 100-yard rig, but as a “walking gun.” Iron-sights, a 50 yard zero and reliable 4 moa grouping with a bigger hole and greater striking energy than a .22 LR to make more reliable kills on raccoon, groundhog, wild turkey or the occasional marauding feral dog is more than practical.

The 26 inch .32 S&W Long barrel is noticeably quieter at comparable subsonic velocities than the 18 inch .32 ACP. Its report is like firing standard velocity .22 LR from a typical sporting rifle. It carries wonderfully and balances better for offhand shooting than the short .32 ACP. Just the ticket for walking fence rows and farm fields in search of furry or feathered edibles in and around the garden. The shorter .32 ACP barrel stows more discreetly in a backpack, when taken down, carries easier through mountainous, brushy thickets and woodlands I often hunt. It comes up a bit faster in snap-shots and is every bit as accurate at practical small game ranges up to 50 yards, as its longer .32 S&W Long counterpart, despite its shorter sight radius.

Lead round nose .32 S&W Long and .32 ACP hardball made clean, round exits in Ivory soap cakes little different than .22 LR solids. Meister 94-grain LFNs in both calibers made larger, dime-sized exits with good small game potential. Fiocchi’s 60-gr. JHP made quarter-sized exits too destructive for camp meat. Cast bullets are best for small game. My little American Rook Rifle shoots better than I can hold with iron sights. Who could ask for anything more than that?


Photos: Top row left top right: (Click on thumbnails to view screen size)

Beretta M1935 with 25-yard groups shot with Saeco #325, left target was fired with original WWII barrel, right target was shot with same load in 14-inch twist Hart .308 groove diameter chambered to headspace on case mouth.

Saeco #325 modified 93-grain hollow-point cast bullets of soft 10 BHN alloy, loaded with 1.8 grains of Bullseye and shot from .32 ACPs of various barrel lengths: Far left 2.4 inch Beretta Tomcat about 700 f.p.s., next two are from 18-inch Rook Rifle about 950 f.p.s., second from right is 3.9 inch Walther PP about 800 f.p.s., far right is 7-inch. Beretta M70 about 850 f.p.s..

Beretta M70 with original 3.5 inch factory barrel shoots well, and was used as test platform for longer custom barrels.

Colt M1903 Pocket Model has salt & peppery bore and dates from 1918, but is the flattest of the bunch and still brings rabbits to the pot like it did for its original owner in the 1930s.

CZ27 was a WWII trophy which refuses to function with US ammo, but loves bullet cast loads.

Bottom Row left to right:

Pre-war H&R .410 shotgun has 26-inch. barrel for .32 S&W Long and 18-inch barrel for .32 ACP. Typical 25-yard groups off sandbags with iron sights are about an inch. Weight about 4 pounds.

Ivory soap block poked with 94-grain Meister bullet from 26" .32 S&W Long barrel at about 1050 f.p.s. shows it is not overly destructive of small game. You can eat right up to the bullet hole.

Beretta M70 with 7 inch custom barrel in Hunter holster as carried for a field rig.

Beretta M70 with 7 inch custom barrel (Douglas .308 10-inch twist) fitted with 4X Leupold scope as used for ammo testing. Scope mount is aluminum muzzle weight having scope rail extending to rear. It was machined in one piece, slides and clamps over barrel with two cap screws. Cast bullet loads shoot as well or better than factory, about 1-1/2 inches or less at 25 yards.

Beretta M70 with 7 inch custom barrel when shot using the factory slide-mounted iron sights shoots about 2-1/2 to 3 inches at 25 yards., not bad for its short sight radius, and is very noticeably quieter, with a useful increase in velocity.

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Seedtick
October 6, 2009, 01:18 PM
Thanks Ed, Interesting read, I enjoyed it.
:)

ST

Mike Kerr
October 6, 2009, 01:58 PM
Great Post.

WOW

What an interesting read. You have a big fan in me.

Now THAT is a contribution to the reloading forum.

regards,

:):):)

Marlin 45 carbine
October 6, 2009, 02:47 PM
great write-up ed. I've switched from BE to Red Dot for my cast slug loads in .32acp however. tighter groups from my Beretta and cleaner loaded with 78gr rn's.

Ed Harris
October 6, 2009, 03:22 PM
I've found Bullseye consistent measuring in the Dillon machines, versatile within its limitations, very cost effective. and very predictable. Not long ago I picked up a case of four 8-lb. caddies at $94.99 per whack, so I don't think I'll be buying any pistol powder for a while.

Jim Watson
October 6, 2009, 03:41 PM
Fascinating, even though my only .32s are a Kel-tec full of Fiocchi for small social occasions, and an elderly Colt just because. I recall Henry Stebbins' friend Bert Shea writing about getting a 6" Dumond barrel and gold bead sight for his Colt. "The first five shots went into the figure 9 at nine o'clock on the American Standard target."

Mostly it is good to see you back in print, Ed. I think you could rewrite the Yellow Pages to be interesting.


I have been looking to tone down the .45 ACP to midrange target load levels and shoot it in IDPA ESP along with the 9mms and .38 Supers so as to keep my .45s in action and spare my joints. Bullseye is the most consistent powder I have found in light loads. Pity I have the other stuff I have tested a little bit that I will have to find uses for.

rdlankfordsr
January 6, 2010, 06:00 PM
I have loaded the 32 Auto for yrs and use 2 to 2.5 grain Unique and a 100 grain LRN. Gives me 860 fps on the low load. I have several 32's but my favorite is a CZ 50 and I have did a one hole ragged 50 rd group at 25 yds. Maybe a little less than 2". This gun just shoots well. Not my usual groups for a pocket gun. Got the load from Cart. of the World. He says 2.8 grains of Unique and a 100 gr Plinker . I have never did over 2.5 of Unique. The 100 gr. bullet gives it a better Wack!!!! No signs of over pressure.........

Ronnie..............

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