Remington has loaded its Core-Lokt bullets for more than 80 years, starting with its Kleanbore cartridges.
Any product that has remained in continual production for decades owes its success to evolving with the times but retaining the features that originally made it successful. Such is why Remington Ammunition’s Core-Lokt bullet has remained in continual production for 83 years and counting.
A low-cost and effective option for hunters aiming at deer has always been the intent of Core-Lokt bullets. Way back when, the Core-Lokt was one of the first rifle bullets to regulate expansion on contact with game. It accomplished that with a jacket thickened at its midpoint and swaged into a lead core to control bullet upset. Deer are thin-skinned with a rather narrow chest cavity, so not all that much punch is required for a bullet to reach the vitals, but it must also expand quickly to take them out.
Bob Hagel wrote in his 1982 book Game Loads And Practical Ballistics For The American Hunter, “… the pointed Core-Lokt bullets loaded in R-P ammunition perform the best of any factory-loaded bullet we have ever used on all sizes of game at all reasonable ranges both for penetration and for expansion.”
The addition of a sharp polymer tip is the latest in Core-Lokt’s evolution. A higher ballistic coefficient (BC) is the new Core-Lokt Tipped’s main advancement for increased downrange performance compared to pointed soft-point (PSP) bullets—a change on the wish list of many long-range hunters.
Core-Lokt HistoryIn the late 1930s, the Peters Cartridge Co. (owned by Remington) introduced a controlled-expansion type of bullet called the “Belted.” The design was rather simple, although it was complex to manufacture. The Belted .30-cal. bullet started as a standard 220-grain hollow point with a gilded metal jacket. A short, separate band around the outside brought the weight up 225 grains and was swaged into the final diameter of the bullet. Upon impact, the nose of the bullet started to upset, but it was checked by the band, and expansion was limited. With expansion curbed, though, the bullet did retain most of its weight to penetrate deeply.
It’s not much of a stretch to say that Remington based its Core-Lokt bullet on the Belted. However, original Core-Lokts were constructed with a thickened jacket on the outside at the midpoint of the jacket. In the final swaging of the bullet, the thick jacket was pressed inward to lock it to the core.
It was plain to see the Core-Lokt was the better of the two bullets in ease of manufacture and performance on game. Remington initially loaded the bullet in Open Point (or “mushroom”) and Soft Point forms for 18 cartridges in its Kleanbore Hi-Speed and Express ammunition. Peters eventually dropped its Belted bullet in favor of the Core-Lokt. In the Peters brand of cartridges, however, the bullet was called the “Inner-Belted.”
World War II put a stop to the manufacture of commercial ammunition, and it wasn’t until 1952 that Remington introduced its Core-Lokt Pointed Soft Point bullets. Few hunters back then worried much about shooting game at extended distances. Nonetheless, the BC of PSP bullets was about 40 percent higher than the BC of Soft Point projectiles. PSP bullets were constructed with a thin jacket at the tip with shallow cuts to initiate expansion.
In 2010, Remington introduced the Core-Lokt Ultra Bonded featuring a PSP bullet with its lead core bonded to its jacket. Remington advertisements stated the bullet expanded at all practical velocities and yet retained 95 percent of its original weight. The bullets are currently loaded in Remington’s Hypersonic Bonded cartridges. They cost about 50 cents apiece more than Core-Lokt cartridges.
Core-Lokt TippedJon Langenfeld has worked as a product engineer for Remington Ammunition during the past 10 years and was recently promoted to manager of the research and development team. Langenfeld wears many green Remington hats supervising production of all aspects of rimfire, centerfire and shotshell ammunition and also the components to make the ammunition.
While adding a polymer tip to a Core-Lokt bullet seems like it should be fairly straightforward, Langenfeld said developing a specific load for a cartridge requires upwards of six months of work from start to finish. Selecting a propellant and a charge weight takes time. “We also test other powders as backups in case a vendor cannot supply the powder we originally wanted to load,” Langenfeld said. Because cartridges may be fired in the sweat of summer or bitter cold of winter, loads are also tested for velocity, pressure and accuracy in different environmental conditions.
As work progresses toward a final load for a given cartridge, time must be set aside on loading machines to run large samples. “We test those loads in four or five different rifles with different barrel lengths and action types,” Langenfeld said. Functioning issues may arise or accuracy may not be quite up to par. Adjusting bullet seating depth may be all that’s required to solve such problems.
“The proof of all that testing is when the cartridges are scaled up to production levels,” Langenfeld said.
To determine how precisely Remington cartridges topped with Core-Lokt Tipped bullets were loaded, I put some .308 Win. cartridges under the microscope, so to speak, of a Hornady Lock-N-Load Bullet Comparator and RCBS Case Master Gauging Tool. The Bullet Comparator measured the length from the face of the head of cases to the ogive of 165-grain Tipped bullets. The lengths of five cartridges varied only 0.003″. The Gauging Tool indicated bullet runout of 0.002″, 0.0015″, 0.002″, 0.001″ and 0.0015″ for five cartridges. Overall cartridge length varied 0.006″ between the five cartridges. Many handloaders wish they could emulate such exact bullet seating.
Remington is initially loading its Core-Lokt Tipped bullets in nine cartridges and 13 loads, from .243 Win. loaded with 95-grain bullets to .300 Win. Mag. seated with 180-grain projectiles. All Tipped bullets wear a boattail, except the .243-cal., which has a flat base. Langenfeld said the ogive on some Tipped bullets are secant while others have a tangent shape.
Rising interest in long-range shooting is evident from magazine articles and website posts, and companies would be missing out by failing to offer products to meet that demand. So the whole idea of the green polymer tip is to increase the aerodynamics of Core-Lokt bullets.
As an example, the .30-cal., 150-grain PSP Core-Lokt has a G1 BC of 0.314, while the same diameter and weight Tipped bullet carries a 0.415 BC. Say both bullets are fired from a .308 Win. at a muzzle velocity of 2,820 f.p.s.—the Tipped bullet’s higher BC results in nearly 1.5″ less drop and 180 f.p.s. more velocity than the PSP Core-Lokt at 300 yards. The Tipped bullet also retains 60 percent of its original energy, while the PSP retains 51 percent. Way out at 500 yards, the Tipped bullet really pulls away from the PSP with 8.5″ less drop and 263 f.p.s. of additional velocity. The Tipped bullet has also held onto 41 percent of its original energy, compared to 31 percent for the PSP. Another way of looking at the Tipped bullet’s advantage is it carries about the same velocity and energy at 500 yards as the PSP bullet does at 350 yards.
So increased downrange performance is accomplished with the Tipped bullet’s better ballistics, not by firing a regular bullet from a larger cartridge with more propellant to achieve that higher velocity. A 180-grain Tipped bullet, fired at 2,745 f.p.s. from a .30-’06 Sprg. has only about 3″ of additional drop at 400 yards compared to a .300 Win. Mag. firing a 180-grain PSP bullet with a muzzle velocity of 2,980 f.p.s.
Core-Lokt Tipped bullets are formed with a hollow point, filled with a polymer tip. On contact with game, the tip is shoved back into the hollow point to start expansion. “Once the initial expansion starts, fluid can now flow into the cavity of the bullet, causing full expansion,” Langenfeld said. “Tipped bullets provide very similar performance on game as regular Core-Lokt bullets.”
Controlling that expansion can be a problem. Core-Lokts do this with a thin jacket at the nose that progressively thickens halfway down its length and then somewhat thins toward the shank. This hourglass shape tightly swages the jacket to the core and helps hold the core in place in the jacket when the bullet expands. I cut a .30-cal. 165-grain Tipped bullet lengthwise in half to look for that thickened section. The cannelure was the only part of the jacket visibly crimped into the core. Melting out the lead core failed to show any hourglass figure to the jacket, however, the jacket greatly thickened from the nose toward the middle and down to the base.
Langenfeld and I went on a Texas mule deer hunt to test the Tipped bullets (sidebar, below), during which he carried a custom .270 Win.-chambered rifle. The 130-grain Core-Lokt Tipped bullet he fired from it hit his buck through the lungs and broke the far shoulder where it came to rest. The bullet expanded back about three-quarters of its length and retained its core to hold onto 51 percent of its original weight. I shot a 165-grain Core-Lokt Tipped bullet from a .308 Win.-chambered rifle that hit my buck at a distance of about 150 yards. The bullet shattered the buck’s near humerus bone, plowed through the front of the lungs and broke the opposite humerus, where it stopped. After that rough ride, the recovered bullet had been mashed pretty flat, however, some of the core remained attached to the jacket, and the bullet weighed 61 grains—or 37 percent of its original weight.
I’ve shot Remington factory-loaded Core-Lokts and handloaded Core-Lokt bullets for decades. Just the other day, I found a box of 6 mm 100-grain Pointed Soft Point Core-Lokt bullets. The red box wore a $7.83 price tag, and I must have bought them at least 45 years ago. For old times’ sake, I handloaded a batch of them with 46.5 grains of W780 propellant in .243 Win. cases. On a blustery November day, I shot them through a pre-’64 Winchester Model 70 Featherweight, and my five, three-shot groups at 100 yards averaged 1.56″.
That started me wondering about the accuracy of Core-Lokt bullets I’ve shot over the decades. Thumbing through some of my reloading records, I found Core-Lokt results for 16 cartridges ranging from .223 Rem. to .35 Whelen. All the rifles chambered in these cartridges were basic hunting rifles wearing iron sights or scopes and were shot with handloaded Core-Lokts paired with a variety of propellants or factory-loaded Core-Lokts. Of the 74 groups noted in my records, some were three-shots and some five-shots, all fired at 100 yards. After a lot of adding and dividing, the 74 groups averaged 1.42″. That’s not too bad. In fact, it’s quite respectable.
During my testing, accuracy was more than satisfactory with the Core-Lokt Tipped 130-grain bullets fired from a .270 Win. and 165-grainers shot from a .308 Win. at 100 yards. The first three-shot group measured 2.15″ fired through a Montana Rifle Co. American Legends Rifle chambered in .270. “That can’t be good,” I thought. However, the four following groups measured 0.99″, 0.62″, 0.58″ and 0.70″, for a five-group average of 1.01″. Standard deviation was 17 f.p.s. over nine shots.
I had no expectations that a Ruger M77 Ultra Light would shoot .308 Win. Core-Lokt Tipped cartridges as accurately; the Ruger rifle had been ridden hard hunting in the mountains for 40 years, and bullets tended to wander when its pencil-thin 20″ barrel heated up. Fire five or more shots in a row, and the barrel is hot enough to light a cigar.
But the Ruger’s accuracy turned out to be a pleasant surprise. Allowing the barrel to cool between shooting groups helped. With no heat waves rising from the barrel, the view of the targets remained clear through the Leupold VX-Freedom scope. The first group fired measured 1.93″; the next four hovered on either side of an inch, for a 1.34″ five-group average. Standard deviation was 14 f.p.s. over nine shots.
“Core-Lokt bullets have always been the bread and butter for Remington,” Langenfeld said. Core-Lokt bullets are not all that elaborate in how they are constructed, enabling them to hold onto much of their weight after hitting game. But they have certainly been proven dependable by millions of hunters in the field over the decades. The addition of Core-Lokt Tipped bullets has moved the enhancement needle upward a tick.
West Texas Mule Deer HuntThe backbone of volcanic mountains builds straight up from the basins of the western Texas desert. One range after another fades desolate and gray into the distance, and, far to the south, the mountaintops of Texas’ Big Bend National Park scrape the sky. Close by, though, the land is alive. Here and there, a windmill creaks in the breeze, pumping water out of bedrock for coveys of scaled quail that flush from sparse grass to catch the moving air and fly like kites amid a scattering of cattle, javelina and mule deer.
Mule deer blend into the gray of the land, and finding them requires covering the country and lots of glassing. The volcanic hills have been crumbling for eons, and hiking the basins and ridges is slow—like walking on bowling balls. The few graded paths and meandering dry creek beds of smooth gravel allowed Josh Coffee, a guide for High West Outfitters (highwestoutfitter.com), to speed up his ATV as we cruised across the country. Mostly, though, it was a slow grind over heaps of rocks and tire to tire from boulder to boulder. And hold on tight; I wouldn’t ride a horse in some of the places Coffee maneuvered his ATV.
Coffee’s game eye was remarkable. “There’s a buck.” He’d point, and it would take a full minute for me to see it. The rut was in full swing in mid-December, and bucks traveled the country most of the day, looking for does during the cool mornings and short-sleeve afternoons.
We saw more than a few bucks wearing high and handsome antlers. But they weren’t quite up to Coffee’s measure. That continued for a few days, until I was the last hunter in camp with a deer tag.
The last day of the hunt, everyone in camp was out to find me a buck. “Should have been here 10 minutes ago,” they said when Coffee and I met up with the others. A big buck had just walked across a basin and disappeared into a brush hillside. Spotting scopes and binoculars emerged to find the buck.
“How about that buck down there?” Coffee pointed. The buck trailed some does. Glimpses of it weaving in and out of the brush showed tall antlers with deep forks.
The stalk was on as Coffee and I made our way down the ridge. Of course, with everyone watching, I missed the buck standing at 250 yards. I buckled down during a run through the brush to find the deer again. The buck’s interest was on a doe, and I shot it a few steps short of 150 yards. The Core-Lokt Tipped bullet fired from the .308 hit it hard through the shoulder. It started to fall as it ran and lay dead just over a rise in the hill. The buck and the ground were the same gray, and it felt like the whole of the desert land was compressed into the buck.