Ed Harris: The .32ACP in a rifle??
Friday, January 06, 2012 Filed in: Rifles, Hunting
Editor’s note: today I’m pleased to bring you another great article from Ed Harris, experimenter extraordinaire. This time he’s built a couple of rifles for some common .32 caliber pistol rounds, making for handy and quiet woods rifles. Enjoy!
Tiny Handgun Cartridges Are Also Small Game Rifle Rounds!
by Ed Harris
After fooling around with a pair of chamber inserts using .32 S&W Long and .32 ACP ammunition in the .30-30, I thought about building a light “walking rifle” which would be handy and quiet. I wanted something more effective than a .22 LR, something which could also approach the ballistics of the .32-20 Winchester. The .32 S&W Long and .32 H&R Magnum cartridges are ideal for such use, but the only factory produced rifle is the Marlin 1894 Cowboy which is neither inexpensive, nor very handy. I wanted something which carried more like a fly rod than a wrecking bar.
Because I frequently carry a .32 revolver or .32 ACP pocket pistol around our country place, I wanted to use those same rounds in a light small game rifle. I would have two barrels made to compare results obtained with the .32 ACP and .32 Smith & Wesson Long. My reasoning was that for very light, quiet “.30 cal. CB cap” loads, that the tiny .32 ACP case would have advantages, whereas the larger .32 S&W Long or H&R Magnum case would had more capacity if I wanted more energy.
My gun safe contained a seldom used H&R .410 single-shot, on the tiny pre-war action, which weighed 4 pounds. John Taylor made two rifle barrels for me, chambered for the .32 ACP and .32 S&W Long (which I later rechambered to H&R Magnum). The .410 barrel remained intact, and the entire package cost less than a new Marlin Cowboy lever-gun. I opted for an 18” barrel chambered in .32 ACP for the most-handy configuration and a 26” barrel in .32 S&W Long for optimum sight radius and minimum noise.
The .32 ACP barrel was fabricated from a pulled-off M1 Garand barrel, cutting off the muzzle behind the gas port and the breech at the chamber neck, turning the OD, fabricating and beam welding on the shotgun underlug and fitting the ejector. The bore is of standard 4-groove .30 cal. Government form with ten inch twist and was chambered with a custom reamer resembling the front half of a .30 M1 Carbine chamber. It headspaces on the case mouth instead of the semi-rim.
The .32 S&W Long barrel is rifled to normal .32 revolver specs with six grooves, right twist, one turn in 16 inches with a bore of .302 and .312 groove diameter.
Firing indoors and comparing both barrels with iron sights, I am satisfied that any handgun ammunition averaging an inch or so over a series of 5-shot groups at 25 yards is adequate for hunting small game. I managed to do so fairly easily with several loads to prove the concept. Winchester .32 S&W Long 98-grain LRN, and .32 ACP Fiocchi and RWS 73-gr. hardball all averaged just under inch groups at 25 yards.
Lead 98-gr. LRN factory loads from the .32 S&W Long 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 was 1214 f.p.s. Fiocchi 60-grain JHPs, which gave 1200 f.p.s. from a 3.5 inch Beretta pistol, screamed out at 1463 f.p.s. in the 18” H&R.
Handloads were next. My goal was not high velocity, but subsonic, quiet small game loads approximating the .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 using the Saeco #325 98-grain SWC and the #322 122-gr. flatnose .32-20 bullets.
The RCBS 32-90CM is a good choice for a common production mold suitable for either caliber. Those not casting their own bullets can buy commercial Meister 94-gr. LFN bullets of .312 diameter. These have the same profile as the flat-nosed factory bullet for the .32 Colt New Police and works well as a heavy .32 ACP bullet. Its ogive length enables a .98” overall cartridge length when taper-crimped in the .32 ACP and when so seated its base does not protrude so deeply into the case that it bulges cases.
Velocities of the .32 ACP cast bullet loads with the 94-grain Meister and 1.7 grains of Bullseye fired from my Walther PP, CZ27 and Beretta 1935 pistols approximate the performance expected from a 4” revolver using the same bullet in the .32 S&W Long with 2.5 grains of Bullseye. When fired from the 18” .32 ACP rifle, the minimum 1.7 grain charge which reliably functions my WWII-era Euro auto pistols approaches the velocity expected of standard .32-20 Winchester factory lead bullet loads fired from a four-inch barreled revolver.
Trying to drive a non-expanding cast bullet intended for small game to supersonic velocity in a rifle is a waste of powder. This is not a 100-yard rig, but a woods “walking gun.” Its iron sights have a hard 50 yard zero, coupled with reliable 4 moa grouping (2 inches at 50 yds) and greater striking energy and penetration than a .22 LR. It shoots clear through critters, making reliable kills on raccoon, groundhog, wild turkey or the occasional marauding feral dog. The rig is practical in its simplicity.
The 26 inch long .32 S&W Long barrel is noticeably quieter than the shorter .32 ACP. After initial testing I rechambered it to .32 H&R Magnum and shot it again. My reasoning was that doing do would enable using HRM brass and factory loads, but wouldn't significantly hurt the grouping with my .32 S&W Long revolver ammo. After rechambering, the tiny 4.5 lb. rifle still shoots one-inch groups at 25 yards with .32 S&W Longs using either the 94-gr. Meister .312" LRN or the LBT .312-105FNBB with 2.5 grs. of Bullseye.
The longer chamber permits seating heavier bullets out in S&W Long brasss to increase powder capacity. With the 122-gr. Saeco #322 bullet for the .32-20, seated to 1.32” overall length in .32 S&W Long brass, crimping in the top lube groove using either 2 grains of Bullseye or 6 grs. of #2400, either load will shoot an inch and half at 50 yards with iron sights over a long series. The same loads fired in a relined English rook rifle I built later approach an inch when using an old Unertl 6X Small Game scope.
Some .32 H&R Mag loads listed in manuals caused ugly looking fired primers in the converted H&R shotgun because of its large shotgun firing pin and un-bushed breech face. I found this a useful indicator of chamber pressure, so I use no load which causes hard opening or smeared primer cups upon opening the rifle when using standard small pistol primers. Firing trials quickly reveal when a load is “too hot,” because hard opening occurs before primer cups noticeably flatten compared to firing the same loads in my revolver. Federal factory .32 H&R loads rub a shiny ring around the firing pin indent, but the action opens with little effort. I therefore presume that a load causing hard opening is over 20,000 psi.
My general purpose load for use in modern .32 S&W Long revolvers and the single-shot H&R uses either the 115-gr. Ideal #3118 or 122-gr. Saeco #322. I cast these of soft scrap, 10BHN, tumble in Lee Liquid Alox, size .314, and load in .32 S&W Long cases with Federal 200 primers and 2 grains of Alliant Bullseye at 1.32" OAL. This gives not quite 850 fps in the rifle and 720 fps in various 4-inch revolvers. It is accurate in both the Ruger Single Six and S&W Model 31. An added benefit is that this load pokes out the front of the cylinder of my old I-frame S&W .32 Hand ejector, which keeps me from putting this warmer-than-factory load in the old gun.
A flat-nosed, solid lead bullet, with large meplat at subsonic velocity is fully adequate in energy and penetration against feral dogs or coyotes. My testing of the Saeco #322 at 850 f.p.s. gave 30 inches of water penetration. If you want a bit flatter trajectory to reach out to 100 yards at the expense of a bit more noise, you can increase the charge to 2.5 grs. of Bullseye in S&W Long brass or 3 grains in H&R Magnum brass. It shoots well at a little over 1000 fps in the rifle and 800-850 fps in the revolver.
I have not fooled much with slower powders, because specialized rifle-only loads defeat the purpose of using the same ammo in both the walking rifle and revolver. I briefly tried #2400 in H&R Magnum loads, up to a nominal “case full” in the .32 Long case. While faster, it was very much louder and less accurate than my mild loads with Bullseye.
The final journey in my search of “Bunny Gun Nirvanna” was in obtaining a real English rook rifle and having it lined to .32 S&W Long. I located an Army & Navy Cooperative Society rook rifle in .255 which had been inexpertly rechambered to .25-20 Winchester. With some botched scope block holes and jackleg barrel restamping, I was able to get it cheap. I sent it to John Taylor to have it relined and rechambered to .32 S&W Long, then upon its return it went to Connecticut for Lucas Geiger to do a full exterior restoration. I now have a plain walking rifle for rough use, and a pretty art piece for yard and range shooting. Both shoot equally well, an inch and a half or less at 50 yards with my chosen loads, with low noise which doesn’t disturb the neighbors. Now to walk the garden!
Wherrrrrre….. arrrrrre…. Yoooooou…. Nooow…Mister. Waaaaaaaaaabbit?