Give the shooting public what they want, and they’ll buy it, right? Well - sometimes.

Case in point: Jeff Cooper’s 10mm.

Sure enough, when the 10mm was unveiled, it looked as though all those predictions were right. After testing Colt’s Delta and the new cartridge, the FBI announced it was going to be their official sidearm and round. Impressed by that endorsement, police departments all over the country began considering rearming with the new 10mm autoloader.

Then an unexpected development developed: Bureau technicians immediately began experimenting with reduced loads. Seems the full-charge ammunition, although it lived up to all advertised velocity and energy specifications, kicked a bit.

Imagine that? A magnum round with lots of recoil! Who’d of thought it? If any of J. Edgar Hoover’s troops complained about the .357’s kick when that caliber was selected as the bureau’s official caliber, it must have escaped my attention. Maybe it’s all that sensitivity training FBI agents are supposed to receive - perhaps it’s really working.

No matter. As a result of the bureau’s experiments, a reduced-load 10mm round was created. Instead of sending a 200-grain flatnose out the muzzle around 1,200 fps, bullet weight was lowered to 180 grains and its launch speed to an advertised 1,000 fps. A short time later, those ballistics were incorporated in a slightly shorter case and baptized the .40-caliber Smith & Wesson. As everyone knows, the .40 S&W is the darling of law enforcement agencies all over the country. According to newspaper reports, bad guys like it too.

To add insult to injury, the FBI decided to swap their Colt Deltas for Berettas. Some reports indicated they would be chambered for the old 9mm cartridge. Others predicted they’d be in the new .40 caliber. Which turned out to be true I can’t say. Don’t care, really. What they shoot is their problem, not mine.

And the 10mm? Well, it looks as though its days are numbered. Remington quit making 10mm ammunition two or three years back. CCI’s new catalog doesn’t list it. Federal’s contains one load featuring a 180-grain jacketed hollowpoint (JHP) at .40 S&W velocities. Winchester is down to one load, but it’s a corker: a 175-grain Silvertip hollowpoint at 1,290 fps that gins up 649 foot-pounds (ft-lbs) of muzzle energy from a test barrel. From my Delta, those loads averaged 1,197 fps some 15 feet from the muzzle. Not bad.

Since Colt dropped the Delta from production, the only arm being chambered for the round is Smith’s Model 610 Classic Hunter - and that might vanish from dealers’ shelves at any moment. No, it doesn’t look like the 10mm has much of a future.

That Model 610, by the way, was originally dropped from production about three or four years ago. It reappeared in Smith & Wesson’s 1998 catalog in response to customer demand that was sparked by 610 owners’ boasts about their sixguns’ remarkable accuracy.

My Model 610 was purchased the first year of production. It was a test gun, but after seeing how it performed at the range, I figured it was one of those happy accidents and bought it. Come to find out, mine was representative of the breed, not a lucky exception. During the following year, 610s racked up a universally recognized reputation for accuracy but were dropped from production anyway. Apparently not many pistolieros were interested in a sixgun chambered for an automatic’s round.

Glancing over my old range data, it’s pretty obvious that accuracy of practically every load tried was above average, whether it was fired in the Delta or the Model 610. There must be something about the cartridge itself that contributes to that kind of a record.

To begin with, the 10mm will accommodate bullets from 140 to 200 grains Ð accurately. In addition, it’s unusually tolerant about powders. Some might give slightly better results than others in individual handguns, but none tested was an obvious mismatch Ð a phenomenon rarely experienced by a handloader. Very fast burning powders seemed to open groups. Slow-burning numbers can’t churn up velocity levels of factory ammunition, but they were certainly accurate enough.

Among my favorites are AAC-7, Unique, AAC-9, Universal Clays, Blue Dot and HI-SKOR 800-X. There’s more than enough published load data available, so there’s no point in repeating it here.

It’s a sturdy case and easy to reload: just give the case neck a slight bell to ease bullet seating, choose bevel-based bullets whenever possible and give each case enough taper crimp to hold its bullet securely.

Both the Delta and Model 610 take to cast bullets like a politician to money under the table. One of my favorite loads in the Delta is built around SAECO’s bullet 047, a bevel-based flatnose weighing 206 grains from my mould. Backed by 10.0 grains of AAC-7, those bullets average 1,095 fps 15 feet from the muzzle. Five-shot strings run from 1.7 to 2.0 inches at 25 yards fired over a rest. All cast slugs were hand-lubed with Alox and fired as-cast. That guarantees groove-filling bullets and lead-free bores.

The first Government Model Colt to come my way was issued to me back in 1942. There has been at least one within reach most of the time since. Of all of them, the Delta 10 is the most consistently accurate, untuned Model 1911 I’ve ever fired. It has benefited from a trigger job since it has been in my possession, but that’s the only ‘smithing it has enjoyed. The factory wraparound grips were replaced by Pachmayr’s Pacwood-rubber American Legend stocks. They improve the Delta’s appearance, and their finger grooves are a definite aid to control.

When the Delta’s clip is stuffed with full-power loads, the big auto rears back with a fair amount of authority. Thanks to that hefty pair of recoil springs, it has more jolt than a .45 automatic but not near as much as a .357 magnum fired in a pistol of the same weight. Using a two-handed hold, the 10mmÕs recoil is more bounce than back-slam. Its muzzle is pushed skyward each time a round goes, but getting back on target quickly has never been much of a problem. Ken Waters mentioned the Delta’s tendency to torque as it recoiled. For some reason, I’ve never noticed that.

Thanks to a beefy 5-inch barrel with full underlug, Smith’s Model 610 is about half a pound heavier than the Delta. Loaded, it feels slightly muzzle heavy, always an aid to steady holding. When fired single action, trigger pull is a consistent 3 1/2 pounds, according to the Chatillon pull tester. Let-off is the usual S&W crisp and, as noted before, accuracy is absolutely phenomenal.

The first time the 610 put five rounds in an inch at 25 yards (from a rest, of course), it was attributed to luck. When it happened again - and again - during load testing, the realization began to dawn that both sixgun and cartridge were unlike anything that had come my way before.

Most five-shot strings cut 1.5 inches at 25 yards, but an impressive percentage went into an honest inch. Anytime groups exceeded 1 1/2 inches, there was no doubt about where the fault lay.

Friends tell me the current Model 610, the Classic Hunter, is delivering the same kind of accuracy. It is available in only one barrel length: 6 1/2 inches. All that extra metal brings its unloaded weight up to 52 ounces. My 610’s recoil feels like that of a .45 Colt. That of the new model must be even tamer.

Periodically I’m tempted to mount a pistol scope on the Model 610 just to see how accurate it really is. In the meantime, it’s used to develop new loads and test new bullets. It also goes along in the pickup sometimes, but as luck would have it, it has never been needed.

One more plus: The Model 610 is as versatile as a dual-cylindered model. With the aid of S&W full-moon clips, shorter-cased .40-caliber rounds can be loaded and fired in its chambers. Accuracy is first class and recoil is hardly noticeable at all. If nothing else, that capability means there will always be another source for usable brass.

To date, the Delta has never been turned against anything larger than jackrabbits and crows. It might be more practical to pack the Model 610 when hunting, but to be honest, the Delta is flatter, more compact and rides easier in a holster when clambering up hill and down dale. It’s also accurate enough Ð at least, it has proved to be so far.

Needless to say, a fast second or third shot capability comes in mighty handy when popping away at a high-stepping, dodging bunny. Most of my hunting loads leave the muzzle around 1,100 fps. Not only do those bullets fly flat and give plenty of reach, but all that velocity allows a noticeable reduction in the required lead, even when ranges stretch out near 100 yards. Equally important, those projectiles hit mighty hard out there. Even with my over-the-hill hearing, the solid thump they make when smacking fur is clearly audible.

At the range, just about any handload will group 2 inches at 25 yards from a rest. A number of factory loads bettered that. One box of Remington 200 grainers averaged 1.7 inches. Velocities of those jacketed flatnoses, measured 15 feet from the Delta’s muzzle, averaged 1,050 fps, and their extreme velocity spread was only 41 fps. Too bad the Big Green is out of the 10mm business.

Thanks to the continuing popularity of the .40 caliber, there should never be any shortage of bullets to choose from. Speer offers four different weights with full-metal jackets: 155, 165, 180 and 200 grains. Winchester stocks 155-, 165- and 180-grain Silvertip hollowpoints for their .40 calibers plus the 175 grainers seated in their sole remaining 10mm load. In addition to the 180-grain hard alloy flatnose seated in their 10mm load, they also market 155-, 165- and 180-grain full-metal-jacketed (FMJ) flatnoses in their .40-caliber rounds. Remington lists five different types in four weights: 141-grain Frangible, 155-grain JHP, 165-grain brass JHP, 180-grain brass JHP and a 180-grain JHP.

So far, all the small game dropped by the Delta fell victim to full-patch flatnoses or Lyman bullet 401638 cast from a Linotype-hard mix. Although the most distant kill I can recall couldn’t have been much over 90 yards away, that full-jacketed truncated cone with its wide, flat face packed a lot of punch. The large crow in my sights seemed to explode in a shower of black feathers, and the "thwack" of the bullet was easily heard.