Published: 2024 | Last updated: June 2026
Introduction
The Remington Core-Lokt has been in continuous production since 1939. That is not a figure of speech or a marketing claim rounded to the nearest decade – 1939 is the actual year, which means this bullet was on store shelves before the United States entered World War II, before synthetic polymers became common manufacturing materials, and before most of the cartridges now chambered in hunting rifles even existed. The Core-Lokt predates the 243 Winchester by 16 years, the 308 Winchester by 13 years, and the 7mm Remington Magnum by 23 years.
The bullet has been updated since 1939 – jacket materials, manufacturing tolerances, and quality control have all improved – but the fundamental design philosophy has not changed: a lead core mechanically locked to a tapered copper jacket, with a soft-point nose that initiates controlled expansion. No polymer tip, no boat-tail on most variants, no bonded core chemistry. Just copper, lead, and a mechanical interlock that has put more North American deer and elk on the ground than any other bullet design in history.
Remington calls it “the deadliest mushroom in the woods,” which is marketing language. The more useful description is this: the Core-Lokt is a flat-base soft-point in the classic cup-and-core tradition, distinguished from comparable designs by the jacket tapering that locks the core in place during expansion and reduces the core separation that causes conventional soft-points to lose penetration depth on heavy bone or at high impact velocity.
The caliber range runs from .224-inch to .375-inch, covering everything from 223 Remington varmint loads to 375 H&H Magnum territory. Weights span 55 to 250 grains. This breadth – combined with near-universal availability at any sporting goods store in North America – makes the Core-Lokt one of the most practical choices for hunters who reload in volume, handload for multiple rifles, or want a reliable hunting component without ordering from specialty suppliers.
Technical Characteristics
The name “Core-Lokt” is not decorative. It describes the bullet’s defining structural feature: the jacket is mechanically tapered so that it grips the lead core along its length, not just at the base. In a conventional cup-and-core soft-point, the jacket is a straight-walled cup that holds the core by pressure fit alone – adequate under normal hunting conditions, but potentially vulnerable to core-jacket separation when impact velocity is high or bone resistance is extreme. Remington’s tapered jacket creates a mechanical interlock that resists separation even as the bullet mushrooms.
The practical result is that Core-Lokt bullets tend to retain more of their weight on impact than conventional straight-walled soft-points under similar conditions – typically 65 to 80% weight retention versus 50 to 70% for designs without the taper. This is not bonded-bullet territory (bonded designs like the Federal Trophy Bonded or Nosler AccuBond regularly achieve 95%+), but it is a meaningful step above the cheapest cup-and-core bullets, and it explains why the Core-Lokt has historically performed reliably on deer and elk even when shots were not perfectly placed.
The soft-point nose exposes enough lead to initiate expansion reliably at impact velocities from 1,800 fps upward. The target expansion is 1.5x to 2x original bullet diameter, which for a .308-inch bullet means a mushroom of .46 to .62 inches. That size produces adequate energy transfer and wound channel diameter on deer through elk at the ranges and velocities the Core-Lokt is designed for.
The flat base is the Core-Lokt’s most significant aerodynamic limitation. Without a boat-tail taper, base drag is higher and the bullet loses velocity more rapidly at distance than comparable boat-tail designs. At 200 yards the difference is minor – 3 to 5% more drop and marginally more wind drift. At 350 yards the gap grows to 10 to 15% more drop compared to a boat-tail design of equal weight and caliber. This is not a problem for the majority of North American whitetail hunting, where shots inside 200 yards in timber and brush represent the realistic range. It becomes a meaningful limitation in open country where 300-yard shots are common.
Remington introduced the Core-Lokt Tipped variant in more recent years, which adds a polymer tip and boat-tail to improve BC and extend the design’s effective range. That variant is a separate product and is not covered here. This article covers the original flat-base soft-point Core-Lokt, which remains the more widely available and more commonly loaded of the two.
The cannelure is standard across Core-Lokt weights. It provides a seating reference, allows crimp application for tubular magazines and semi-automatic platforms, and contributes to bullet retention under recoil in rifles with aggressive springs or significant muzzle blast.
Neck tension during reloading should be maintained at the standard 0.002 to 0.004 inches of interference fit. The Core-Lokt’s flat base and conventional profile make it compatible with any standard sizing die without special setup.
Disclaimer: Reloading is an inherently dangerous activity. Always consult current published load data from reputable sources (Remington, Hodgdon, Hornady, Lyman) before loading any cartridge. Start at minimum charges and work up carefully while watching for pressure signs. Never exceed maximum published loads. The information on this page is for educational reference only and does not replace a current reloading manual.
Ballistics and Performance
G1 BCs from 0.200 to 0.300 are honest numbers for a flat-base soft-point in conventional cup-and-core construction. These figures are comparable to the Sierra Pro-Hunter (0.185-0.310) and Federal Power-Shok (0.190-0.290), and notably lower than boat-tail designs like the Sierra GameKing (0.185-0.517) or polymer-tipped options like the Sierra Tipped GameKing (0.323-0.545).
To put BC 0.266 for the 150-grain .308-inch Core-Lokt in concrete terms: from a 308 Winchester at 2,820 fps muzzle velocity, this bullet drops approximately 6.5 inches at 200 yards and around 19 inches at 300 yards with a 100-yard zero. Wind drift in a 10 mph crosswind is about 3.5 inches at 200 yards and 8 inches at 300 yards. These are manageable figures for deer hunting at those ranges – the animal’s vital zone is larger than the margin of error in a careful hold. At 400 yards, the arithmetic becomes less forgiving: drop is around 42 inches and drift reaches 15 inches, which is where the flat-base BC limitation starts to matter in practical hunting scenarios.
Accuracy runs 1.0 to 1.5 MOA in typical hunting rifles. This is slightly behind the best-performing conventional soft-points like the Sierra Pro-Hunter (0.8-1.5 MOA) and Sierra GameKing (0.5-1.0 MOA), but adequate for ethical hunting inside the Core-Lokt’s effective range. Some barrels shoot Core-Lokt bullets surprisingly well, achieving sub-MOA groups that suggest the accuracy reputation is conservative. Others show a strong preference for different bullets. The only way to know is to test in your specific barrel.
The 250-grain .375-inch Core-Lokt at BC 0.300 and SD 0.254 is worth noting as the heaviest and least commonly seen variant. At .375 H&H Magnum velocities, SD 0.254 provides adequate penetration on large African plains game and Alaska-class North American animals. The Core-Lokt is not a dangerous game bullet in the professional sense – that application calls for purpose-built solids or premium bonded designs – but for elk and moose where the .375 H&H is sometimes used by North American hunters, the 250-grain Core-Lokt is a functional and significantly less expensive option than premium alternatives.
Expert Ballistics Table – Remington Core-Lokt Variants
Data from Remington specifications. BCs are G1 values. Verify current figures on Remington’s website before load development.
| Diameter (inches) | Weight (grains) | BC (G1) | Sectional Density | Application |
|---|---|---|---|---|
| .224 | 55 | 0.200 | 0.157 | Varmints, small game in 223 Remington |
| .243 | 100 | 0.276 | 0.242 | Deer, antelope in 243 Winchester |
| .264 | 140 | 0.248 | 0.287 | Deer, elk in 6.5 Creedmoor and 260 Remington |
| .277 | 130 | 0.242 | 0.242 | Deer, antelope in 270 Winchester |
| .284 | 140 | 0.248 | 0.248 | Deer, black bear in 7mm-08 Remington |
| .308 | 150 | 0.266 | 0.226 | Deer – standard 308 Winchester and 30-06 Springfield weight |
| .308 | 180 | 0.254 | 0.271 | Elk, large deer in 30-06 Springfield |
| .338 | 200 | 0.288 | 0.250 | Elk, moose in 338 Winchester Magnum |
| .375 | 250 | 0.300 | 0.254 | Large game in 375 H&H Magnum territory |
The 140-grain .264-inch Core-Lokt at SD 0.287 is an interesting data point. Sectional density of 0.287 at 6.5mm diameter is genuinely high – higher than the 180-grain .308-inch at SD 0.271 – which means the 140-grain 6.5mm Core-Lokt penetrates very deeply for its caliber. Paired with 6.5 Creedmoor or 260 Remington, this combination produces a mild-recoiling load with excellent penetration potential on deer and lighter elk at moderate ranges. The BC 0.248 limits its downrange performance compared to higher-BC 6.5mm bullets, but inside 250 yards it is a capable and affordable hunting load.
Comparison Bullets
The Core-Lokt’s natural comparison set is other flat-base conventional soft-points, because that is the category it actually belongs to and competes in.
The Sierra Pro-Hunter is the most direct comparison. Both are flat-base, lead-core, copper-jacket soft-points with similar BC ranges and comparable terminal performance at hunting ranges. The Sierra Pro-Hunter has a slight accuracy edge in most rifles (0.8-1.5 MOA versus Core-Lokt’s 1.0-1.5 MOA), covers a wider range of calibers and weights (up to .458-inch and 400 grains versus Core-Lokt’s .375-inch and 250 grains), and has a slightly more consistent reputation for tight lot-to-lot manufacturing tolerances. The Core-Lokt is typically less expensive per bullet and easier to find at rural sporting goods stores outside major cities. For most hunters, either bullet produces identical field results on deer.
The Federal Power-Shok is the most direct budget comparison. BCs and weights overlap almost entirely with the Core-Lokt, and field terminal performance is indistinguishable at normal hunting ranges. The Power-Shok is typically the least expensive of the three flat-base soft-points. It does not have the Core-Lokt’s tapered jacket lock, which means weight retention may be slightly lower on heavy bone impact, but the practical difference on deer-sized game is negligible.
Against boat-tail designs, the comparison is straightforward: the Sierra GameKing and Sierra Tipped GameKing outperform the Core-Lokt aerodynamically at any range past 200 yards. At 100 yards the difference is invisible on a deer. At 300 yards it is measurable on paper and relevant in wind. If your hunting consistently involves open-country shots past 250 yards, a boat-tail design is worth the modest price premium. If your shots are inside 200 yards in the field, the Core-Lokt’s aerodynamic disadvantage is irrelevant.
Against premium bonded designs like the Federal Trophy Bonded, Nosler AccuBond, and Nosler Partition, the Core-Lokt is outclassed in weight retention and resistance to jacket-core separation on heavy bone at high velocity. On a broadside whitetail at 150 yards, that difference is academic. On a bull elk hit in the shoulder at 50 yards from a 300 Winchester Magnum, the Core-Lokt might fail where a bonded bullet would drive through. The price difference between Core-Lokt and premium bonded bullets is significant – roughly three to five times per unit. Whether that premium is justified depends entirely on what you are hunting and how you are hunting it.
Polymer-tipped designs like the Hornady SST and Nosler Ballistic Tip offer BC advantages over the Core-Lokt at similar weights due to the boat-tail base and polymer tip combination. They also expand more aggressively on deer – sometimes dramatically so – which produces visible wound channels but can mean reduced penetration at close range. The Core-Lokt’s more gradual, controlled expansion is less spectacular on deer tissue but more predictable across the full range of impact velocities.
Comparison Table – Flat-Base Conventional Soft-Point Hunting Bullets
| Bullet | Diameter Range | Weight Range | BC Range | Core Lock | Relative Cost |
|---|---|---|---|---|---|
| Remington Core-Lokt | .224-.375 | 55-250 gr | 0.200-0.300 | Tapered jacket mechanical lock | Budget-Mid |
| Sierra Pro-Hunter | .224-.458 | 55-400 gr | 0.185-0.310 | Pressure fit | Budget-Mid |
| Federal Power-Shok | .224-.458 | 55-300 gr | 0.190-0.290 | Pressure fit | Budget |
| Sierra GameKing | .224-.375 | 55-250 gr | 0.185-0.517 | Pressure fit, boat-tail | Mid |
| Hornady InterLock | .224-.458 | 55-400 gr | 0.200-0.360 | InterLock ring | Budget-Mid |
The Hornady InterLock deserves mention here because it is a direct design-philosophy competitor to the Core-Lokt. Where Remington uses a tapered jacket to lock the core, Hornady machines an internal ring into the jacket that the core flows into during manufacture. Both approaches resist core separation better than a plain pressure-fit jacket, and both land in the same BC range and price category. The choice between Core-Lokt and InterLock for deer hunting is largely a matter of which one shoots better in your specific barrel.
Applications and Practical Aspects
The Core-Lokt’s eight decades of continuous production have produced an unusually well-documented field record. Hunters know how it performs because millions of rounds have been fired at game under real conditions – not just in laboratory gelatin. Here is how the different weights map to practical hunting applications.
Varmints and small game (.224-inch, 55 grains): The 55-grain Core-Lokt at BC 0.200 is a functional varmint round from 223 Remington or 222 Remington at ranges inside 200 yards. Beyond that, purpose-built varmint bullets like the Hornady V-MAX, Sierra Varminter, or Sierra BlitzKing offer substantially better aerodynamics and more explosive expansion for dedicated varmint work. The 55-grain Core-Lokt is better understood as a light deer bullet in 22-250 Remington where it is legal, not as a varmint specialist.
Deer and antelope (.243-inch, 100 grains): The 100-grain .243-inch Core-Lokt is one of the most field-proven deer loads available. In 243 Winchester with Hodgdon Varget, IMR 4064, or Hodgdon H4350, it produces reliable 1.0 to 1.5 MOA accuracy and expands consistently on deer at 243 Winchester velocities at ranges inside 250 yards. SD 0.242 is adequate for deer and antelope. For longer shots in open country, the Sierra GameKing 100-grain at BC 0.361 is a better aerodynamic choice. For inside-200-yard whitetail hunting, the Core-Lokt delivers the same terminal result at lower cost.
Deer, elk (6.5mm, 140 grains): The 140-grain .264-inch Core-Lokt in 6.5 Creedmoor or 260 Remington is an underappreciated combination. SD 0.287 is high enough for elk at moderate ranges, expansion at 6.5mm hunting velocities is reliable and controlled, and the price point makes it practical for high-volume practice sessions followed by hunting with the same component. Powders like Hodgdon H4350, Alliant Reloder 16, and IMR 4064 pair well with this weight. The BC 0.248 limits it to inside 250 yards for elk, but that covers the majority of mountain and timber elk hunting scenarios.
Deer, antelope (.277-inch, 130 grains): The 130-grain .277-inch Core-Lokt in 270 Winchester is a classic deer combination with decades of field validation. Jack O’Connor, the famous gun writer who spent much of his career championing the 270 Winchester, used Core-Lokt bullets for much of his hunting. The combination works – 270 Winchester velocity with 130-grain Core-Lokt produces reliable expansion and adequate penetration on deer and antelope inside 250 yards. Powders like Hodgdon H4350, IMR 4350, and Alliant Reloder 19 are standard for this application.
Deer, black bear (7mm, 140 grains): The 140-grain .284-inch Core-Lokt in 7mm-08 Remington or 7×57 Mauser at SD 0.248 is a reliable deer and black bear load at moderate ranges. The tapered jacket lock provides better weight retention than a plain soft-point on black bear shoulder bone, which makes the Core-Lokt a sensible choice for hunters who use the same rifle for both deer and opportunistic bear. Hodgdon Varget, IMR 4064, and Alliant Reloder 15 work well at this weight.
Standard deer, elk (.308-inch, 150-180 grains): These two weights are the Core-Lokt’s sales volume center. The 150-grain .308-inch is the standard North American deer hunting weight in 308 Winchester and 30-06 Springfield – flat trajectory, manageable recoil, reliable expansion. Powders like Hodgdon Varget, IMR 4895, Hodgdon H4895, and Alliant Reloder 15 cover this weight well in 308 Winchester. The 180-grain .308-inch at SD 0.271 adds penetration for elk and large deer, trading some velocity for deeper penetration. In 30-06 Springfield with Hodgdon H4350 or IMR 4350, the 180-grain Core-Lokt at 2,700 fps is a traditional elk load with a long field record. It is not the most aerodynamically efficient choice, but inside 250 yards it kills elk reliably when the bullet is placed correctly.
Elk, moose (.338-inch, 200 grains): The 200-grain .338-inch Core-Lokt in 338 Winchester Magnum at SD 0.250 is a legitimate elk and moose bullet at moderate ranges inside 250 yards. BC 0.288 limits its long-range utility compared to higher-BC .338-inch bullets, but the core lock construction provides adequate weight retention on the heavy bone of bull elk and moose at 338 Winchester Magnum impact velocities. Slow powders like Hodgdon H4831SC, Alliant Reloder 22, and IMR 4831 are appropriate for this application.
Large game (.375-inch, 250 grains): The 250-grain Core-Lokt at SD 0.254 in .375 H&H caliber covers North American big game at close to moderate ranges. BC 0.300 is modest for the caliber, but .375 H&H hunting is rarely conducted past 200 yards in practice. The tapered jacket lock provides better core retention on heavy game than a plain soft-point at .375 H&H impact velocities. For Alaskan brown bear or moose, a purpose-built bonded or partition design is a more conservative choice, but the Core-Lokt 250-grain is a functional and significantly less expensive option for budget-conscious hunters using this caliber on elk and moose.
Reloading
The Core-Lokt is one of the most straightforward bullets to reload. Its conventional flat-base profile, standard dimensions, and well-documented pressure behavior mean that any major reloading manual will have applicable data and any standard die set will work without modification.
Primers: Standard large rifle primers cover all 30-caliber and larger applications. CCI 200, Federal 210, Winchester WLR, and Remington 9-1/2 are all reliable choices. For smaller cartridges in 223 Remington and 243 Winchester range, standard small rifle primers CCI 400, Federal 205, and Winchester WSR are appropriate. For 223 Remington in AR-platform semi-automatic rifles, the CCI No. 41 mil-spec primer with its harder cup prevents slam-fire. For magnum applications with 338 Winchester Magnum and slow-burning powders, magnum primers CCI 250, Federal 215, or Remington 9-1/2M provide consistent ignition.
Cases: Standard brass from Remington, Federal, Winchester, and Lapua all work well. Remington brass is a natural pairing with Remington bullets and widely available. For applications where case consistency matters – competition, long-range load development – Lapua brass provides better dimensional uniformity and longer service life. Military surplus brass with crimped primer pockets requires swaging before use. Berdan-primed cases from 7.62x54R or 303 British military surplus are not suitable for reloading with standard dies.
Seating Depth: Start at 0.010 to 0.050 inches off the lands. The Core-Lokt’s flat base makes it slightly less sensitive to small seating depth changes than high-BC boat-tail bullets, which simplifies load development. For most hunting rifles with magazine constraints, seat to the maximum overall length that chambers and feeds reliably. The cannelure provides a consistent seating depth reference that is useful when loading in volume.
Crimp: Apply a light roll crimp at the cannelure for tubular-magazine lever guns, semi-automatic rifles, or any application involving significant recoil where bullet setback during magazine feeding is a concern. For bolt-action hunting rifles, proper neck tension without a crimp is sufficient to hold the bullet firmly during handling and chambering.
Barrel Twist: Standard twist rates for each caliber are appropriate across Core-Lokt’s weight range. 1:12 for the 55-grain .224-inch, 1:10 for the 100-grain .243-inch and most .277-inch and .308-inch weights, 1:10 for the 200-grain .338-inch, and 1:14 for the 250-grain .375-inch which is a short, heavy bullet that stabilizes readily. Confirm your barrel’s actual twist rate before loading the heaviest variants.
Powder Selection by Application:
| Application | Caliber | Bullet Weight | Recommended Powders |
|---|---|---|---|
| Varmints | 223 Rem | 55 gr | Hodgdon Varget, Hodgdon CFE 223, Hodgdon H335 |
| Deer | 243 Win | 100 gr | Hodgdon Varget, IMR 4064, Hodgdon H4350 |
| Deer/elk | 6.5 Creedmoor | 140 gr | Hodgdon H4350, Alliant Reloder 16, IMR 4064 |
| Deer | 270 Win | 130 gr | Hodgdon H4350, IMR 4350, Alliant Reloder 19 |
| Deer/bear | 7mm-08 Rem | 140 gr | Hodgdon Varget, IMR 4064, Alliant Reloder 15 |
| Deer | 308 Win | 150 gr | Hodgdon Varget, IMR 4895, Alliant Reloder 15 |
| Elk | 30-06 Sprg | 180 gr | Hodgdon H4350, IMR 4350, Hodgdon H4895 |
| Elk/moose | 338 Win Mag | 200 gr | Hodgdon H4831SC, Alliant Reloder 22, IMR 4831 |
Reloading Parameters Summary:
| Parameter | Guideline |
|---|---|
| Neck tension | 0.002-0.004 inch interference |
| Seating depth | 0.010-0.050 inch off lands |
| Crimp | Required for tubular magazines; optional for bolt-action |
| Minimum expansion velocity | 1,800 fps at target distance |
| Extreme spread target | Under 20 fps for hunting accuracy |
| Storage | Cool, dry, sealed container |
Load data note: Core-Lokt data appears in Remington’s own reloading manual and in all major third-party manuals including Hodgdon, Hornady, and Lyman. Unlike some premium component bullets, published load data for Core-Lokt is abundant and well-validated. Always start at published minimum charges and work up in 0.5-grain increments while watching for pressure signs: flattened primers, sticky extraction, and cratered primer pockets are all signals to stop and back off the charge.
Conclusion
The Remington Core-Lokt has been killing deer for 87 years. That number is worth sitting with for a moment, because no bullet design stays in production for 87 years by failing to work. Hunters who tried it in the 1940s told hunters who started in the 1960s, who told hunters who started in the 1980s, who buy it today. The word-of-mouth chain is eight decades long.
What the Core-Lokt actually is – stripped of the nostalgia and the marketing – is a flat-base conventional soft-point with a tapered-jacket mechanical core lock that provides better weight retention than the cheapest cup-and-core designs without the cost of bonded construction. G1 BCs of 0.200 to 0.300 are honest for the design, and limit effective range to inside 300 yards in practical hunting scenarios. Inside that range, on deer through elk, it is a reliable and proven choice that is available at virtually every sporting goods counter in North America.
Choose the Core-Lokt if: you hunt deer, elk, or black bear inside 250 to 300 yards in terrain where long shots are not common, you want wide availability without special ordering, you are budget-conscious and loading in volume, or you are new to handloading and want a simple, well-documented bullet for your first hunting loads. The 270 Winchester 130-grain, 308 Winchester 150-grain, and 30-06 Springfield 180-grain Core-Lokt loads in particular have decades of field validation behind them.
Choose something else if: you regularly hunt open country where shots past 300 yards are realistic – a boat-tail design like the Sierra GameKing or Sierra Tipped GameKing will serve you better aerodynamically at that range. If you are hunting elk or moose at magnum velocities and want the best possible weight retention on heavy bone, a bonded design like the Nosler AccuBond, Federal Trophy Bonded, or Nosler Partition provides a reliability margin the Core-Lokt cannot match. If you are hunting in a lead-free zone, you need a monolithic like the Barnes TSX or Barnes TTSX.
For the hunter who shoots inside 250 yards on medium to large North American game and wants a proven, inexpensive, widely available hunting bullet – the Core-Lokt is as good a starting point as it was in 1939.
Disclaimer: Reloading involves inherent risks. Always use current load data from published manuals. Never mix data from different sources for the same load. Start below maximum charges and increase gradually. Wear eye protection at all times. The author and myreloading.com are not responsible for injuries or property damage resulting from reloading or shooting handloaded ammunition.
Have you hunted with the Remington Core-Lokt? Leave a comment with the details: bullet weight, cartridge, game, range, shot angle, and what you observed on impact. The Core-Lokt has an enormous collective field record – the community’s combined experience covers every cartridge it is made for and probably every game animal it has been used on. Did the tapered jacket lock actually hold up better than a plain soft-point on a shoulder shot? Did you ever have a failure? What weight and cartridge combination worked best for your specific hunting? All of it is useful.
Editorial note: Originally published 2024, revised June 2026. The update expanded the introduction with the full 1939 design history and the practical meaning of 87 years in continuous production, added detailed explanation of the tapered jacket mechanical lock and how it differs from bonded construction and from plain pressure-fit soft-points, expanded the comparison section to include the Hornady InterLock as a direct design-philosophy competitor, added the Jack O’Connor historical note for the 270 Winchester 130-grain application, added specific drop and wind drift figures for the 150-grain .308-inch at representative ranges, added a full powder selection table by cartridge and application, and applied full internal linking throughout.
