Having your Cake and Eating it Too!
(Hollow Point Bullet Moulds)
 
© 2014 – Ed Harris
 
Properly designed hollow-point cast bullets expand at
Subsonic revolver velocities without requiring +P charges
 
 

The standard of terminal performance from a concealable .38 Special service revolver was for many years the so-called “FBI load. It featured a 158-grain all-lead, hollow-point, semi-wad cutter at a velocity of 880 f.p.s. as obtained from a four-inch vented test barrel, which approximates what you can expect from a “wheel gun.” Winchester sold it under its symbol X38SPD. Remington’s equivalent was R38S12 and Federal’s 38G. Winchester and Remington loads are still available from Midway. Federal no longer makes it.

The “FBI Load” expands “most of the time” to about .54-.60 caliber from a 4-inch revolver and penetrates 12 inches of gelatin tissue stimulant. Firing it from a 2 inch pocket revolver reduces velocity about 50 f.p.s. Expansion is then less consistent and limited to about .45-50 cal., when it occurs. Reduced expansion increases penetration, which can sometimes be a good thing.

Getting reliable expansion from common 3 percent antimony (11BHN) lead swaging alloy, requires a striking velocity above 850 f.p.s. Achieving this with 158-gr. bullets from a two inch snub requires a +P load unless cylinder gap tends towards the minimum assembly tolerance of .004.” Tighter gaps cause cylinder binding if you fire more than a cylinder full or so of +P lead rounds. Expect a Delta-V of ten f.p.s. per 0.001” of gap difference from the maximum industry assembly tolerance of .008”.

Lead bullets enable higher velocities within permissible non +P pressures as required for use in light frame revolvers. Hollow-point cavity geometry must also be optimized to enable low velocity expansion. Swaging lead hollow-points with large nose cavities is difficult because the bullets tend to “stick” on the nose punch and therefore get mangled in the machine, unless the punch has sufficient taper or “draft” so that the bullet readily falls off. Meplat diameter and required punch draft limits practical cavity size. Large hollow-point cavities in soft alloy are easily damaged by normal handling, loading and shipment, producing higher scrap rates, reduced marketing cosmetics, and lower profit margins. Federal’s 125-gr. Chief’s Special non+P hollow point .38 Special had a good street record, but was expensive to make, a low volume seller, low profit, so was discontinued.

To get low velocity revolver bullets which expand, you can make your own.

The trick is getting a design which actually “works.” That being said, I neither use nor recommend hand-loaded ammunition for defense. I carry either factory wad-cutters or Winchester 110-grain non +P Silvertips in light alloy frame guns and the Winchester X38SPD +P in steel ones. The purpose for casting my own lead hollow-points is for field use and to conserve my $33-a-box factory loads.

My experience with Lyman hollow-point moulds was less than Ideal (pun IS intended). Using a Forester hollow-pointer is somewhat better, but with simple straight drills cavity shape still isn’t “right.” Best results were obtained taking a cast bullet with large meplat, holding it in a fixture and machining a cup point of a depth approximating 0.6 of meplat diameter using a sharp-pointed, 82-degree countersink. This shallow cup point works well in soft alloy such as 1:25, but is tedious to produce if you want more than a few. Then CBA member George Damron introduced me to Erik Ohlen, www.hollowpointmould.com

I contacted Erik, discussed ideas, and we agreed to collaborate. I sent him several moulds, exchanged email and in a short time my modified moulds came back. I fired up the lead pot immediately and after pre-heating the blocks on a hot plate, it took only a dozen pours to get bullets good enough to hand lube, load and shoot right away.

The first mould I tested was a Saeco #358 cowboy bullet. In original solid configuration it weighs 163 grains in soft backstop scrap. I had Erik modify the blocks from 4 cavities to three, to reduce its weight, while having the center cavity hollow-pointed using a removable core pin. Reducing block size to 3-cavities improves handling so the mould is handier to use. A 147-gr. HP is a good weight for fixed-sight .38 Specials and shoots to the same point of impact as Saeco #358 double-end wad-cutters I use for field shooting and practice.

The other block I sent was a double-cavity iron block NEI #161A. In original solid configuration it weighs 188 grains at 10BHN. Erik’s recommended “cup point” version of this bullet weighs 175 grains. Converting one cavity of a 4-cavity block can also be done, but is less convenient, because the core pin handle protrudes from the bottom and interferes with using a mould guide and a heavy mould is tiring to use without one. I solved this by stacking ceramic tiles underneath my RCBS bottom-pour pot to produce a non-stick platform to support the handle, which was readily adjustable as needed to fit the mould block.

My intent was a flat-nosed bullet for tubular magazine use which would expand in quiet, subsonic field loads when fired from a cowboy rifle or using non +P loads fired from a short-barreled revolver. I wanted to approximate the expansion of the "FBI" load using a home-cast bullet, without having to load to +P pressures which would loosen my old Colts.

I loaded test rounds in .357 Magnum brass using 4.2 grains of Alliant Bullseye to approximate .38 Special +P velocity and shot them into water jugs from ten feet from a Ruger Security Six with 2-3/4 inch barrel. Estimated velocity was 830 f.p.s. based upon previous tests. Both bullets blew the first jug apart, split the next one lengthwise and continued straight-on to give 20 inches of water penetration. This approximates 13 inches of gelatin. Expansion was classic mushroom without fragmentation, to about 0.70 caliber. Repeating the water expansion tests again in .38 Special brass using 3.5 grains of Bullseye producing about 750 f.p.s. from, my 2 inch Colt Detective Special gave expansion to .54-.58 caliber. This approximates the expansion of Winchester X38SPD service loads fired from a 4-inch barrel, but does so at lower velocity from a two inch snubby.

I then did some accuracy testing using 3.5 grains of Bullseye in the .38 Special with the 147-gr. Saeco #358HP. An average of five consecutive 6-shot groups fired from my Colt Officer's Model Match off sandbags at 25 yards averaged 1.72 with the largest group 2.55 and the smallest 1.13. I started from a clean barrel. The first two groups were the largest. As the bore became conditioned with the Lee Liquid Alox, groups settled down, which is normal. The last three groups were all less than 1.5 inches, which is what I expect with this revolver using good wad-cutter ammo. Expansion of these non +P loads fired from the 6 inch revolver approximated what I got using .357 loads with 4.2 grains of Bullseye fired from the Ruger snubby. This hollow-point bullet does all I could ask of it.

Firing the .38 Special 147-grain loads from a 24-inch. Marlin Cowboy rifle (1000 f.p.s.) into water, blew off the expanded nose in large fragments, with the remaining shank retaining 55%-65% of original weight, depending upon depth adjustment of the core pin. Changing the core pin to wider and shallower 82 degree countersunk cup point increases as-cast weight of the NEI #161A to 175 grains. In water jug tests it still enabled the bullet to expand very well, to .54 caliber, without fragmentation. Erik recommends the cup point bullet for rifle and magnum revolver use at supersonic velocities. With soft alloys up to 12 BHN it is effective up to maximum plain-base velocities. Using GC designs 12 BHN alloy can be used for hunting to about 1800 f.p.s. and 14 BHN to about 2000 f.p.s. with classic mushroom performance. Heat treated low-Sb alloys can be driven faster.

Applying these principles to rifle bullets:

Erik’s designs of hollow-point bullets agree with hunting experience. Traditional Lyman style, small diameter, deep core pins producing a cylindrical cavity shape or tiny tapered point often collapse in oblique impacts. They may expand if cast in soft alloy when they hit almost exactly point-on, but expansion at oblique angles is often unreliable. Larger, angular hollow-point cavities such as used in the Speer law enforcement bullets, when applied to cast designs, facilitate filling cavities with grease or wax to prevent their plugging with debris. Wax or grease behaves as a fluid to vector the impact forces outward against the cavity walls to enhance low velocity expansion. Sharp-edged meplats readily "dig in" on oblique impacts and are less easily deflected upon striking bone than a round-nosed profile. Erik can convert round-nosed moulds to flat-nose for safe use in tubular magazines or to provide a larger meplat. By using a larger diameter core pin, bullet length and projectile weight are reduced by truncating the original ogival curve at its new intersect point with the hollow point core pin.

Americans are brainwashed by ammunition catalogs to want double-caliber expansion with 85 percent weight retention. Maximum expansion inhibits penetration, which can impair performance on large animals. Europeans have used fragmenting hunting bullets for many years and they are well proven. RWS H-Mantel and the original Nosler Partition bullets were designed to expand, and then slough off the expanded nose in large fragments, which cause secondary wound channels.

Standard conversions are for a single cavity block or for one cavity in a gang mould, supplying one removable core pin with handle. Cramer-style multi-cavity hollow-point conversions are in development. When sending moulds for conversion, it is necessary to specify the intended velocity to ensure that the proper design of core pin is provided. Additional core pins of different shapes, size-lubricator top punches, and seating die punches which preserve the as-cast cavity, are available at extra cost.

Erik‘s “subsonic” core pin design has a large, deep, tapered hollow-point cavity intended to ensure low velocity expansion at 750-800 f.p.s. using soft alloys approximating 10 BHN such as 1:25 tin/lead in calibers such as the .32 S&W Long, .38 Special, .44 Special .45 Auto Rimmed. Use of somewhat harder alloy such as wheel-weights, at 12 BHN, or 50-50 plumbers lead and linotype at 13 BHN, enable its use for magnum revolvers and gas-checked rifle bullets, while limiting fragmentation at supersonic velocities to approximately one third to one half of bullet weight. A fragmenting bullet is effective as long as half or more of original bullet weight remains intact to continue penetration. RWS H-Mantels are so designed and are proven hunting bullets of outstanding reputation.

Erik’s “high velocity cup-point” is intended for supersonic velocities as produced by magnum revolvers. It also enables good expansion with deep penetration when used in gas-checked rifle loads using bullets having a large meplat, such as in the .44 Magnum and .45-70. It produces slower expansion with a classic mushroom shape with weight retention similar to conventional jacketed soft points. It is best suited for heavier game, and enables alloy hardness to be adjusted as needed to match the velocity and pressure of the chosen load. An alloy of 50-50 wheel weights + plumber’s lead with 1 percent tin added is recommended for revolver use and rifles below 1600 f.p.s. For gas-checked high velocity loads cast the same alloy hot and water quench bullets from the mould.

As I have a chance to get more experience with other moulds in work and Erik hears from other customers, you will see more results here. But I think he has something going. 8-)

 
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