History
Winchester introduced the .284 Winchester in 1963 to solve a packaging problem: deliver .270 Winchester and .280 Remington performance from a short action. The fix was a fat case with a rebated rim, body wider than the .473 inch rim, holding enough powder to keep pace while still feeding through a standard bolt face. The first chamberings were the short-action Model 88 lever gun and Model 100 autoloader.
As a hunting round it never caught on, and factory ammunition is sporadic at best. Its second life made the reputation: long-range and F-class shooters took to the efficiency and accuracy, and the case spawned a whole family of wildcats, the most famous being the 6.5-284 Norma.
Lineage
The rebated rim is the whole trick: a .500 inch body on a .473 inch rim, so the wider powder column rides a standard-bolt-face action. It pushes a 7mm (.284 inch) bullet. The lasting legacy is as a parent case. Necked down to 6.5mm it becomes the 6.5-284 Norma, and it has fathered 6mm and other wildcats besides. Its closest relative in spirit is the 7mm-08 Remington, which delivers similar short-action 7mm performance from a conventional case.
Specifications
| Spec | Value |
|---|---|
| Case type | Rimless (rebated), bottlenecked |
| Bullet diameter | 7.21 mm (.284 in) |
| Neck diameter | 8.13 mm (.320 in) |
| Shoulder diameter | 12.06 mm (.475 in) |
| Base diameter | 12.70 mm (.500 in) |
| Rim diameter | 12.01 mm (.473 in, rebated) |
| Case length | 55.12 mm (2.170 in) |
| Overall length | 71.12 mm (2.800 in) |
| Case capacity | ~66 gr H2O (nominal; varies by brand) |
| Primer size | Large rifle |
| Belted | No |
| Rifling twist | 1 in 9 in (SAAMI reference); 1 in 8 in (recommended, for heavy match) |
| Max pressure | 56,000 psi (SAAMI) |
| Recommended barrel | 28 in, 1:8 twist |
Barrel Design
These days the .284 lives in the hands of handloaders and target shooters, and that shapes the barrel choices. They seat long, heavy 7mm match bullets in the 168 to 180 grain class, so a 1:8 twist is the right call to hold them with margin. The slower 1:9 to 1:10 twists on the old factory hunting rifles handle lighter bullets but throw away the long-range potential, which is the whole reason to shoot one.
On length, the .284 is efficient rather than overbore, but the heavy-bullet target role still calls for a long barrel. A 28 inch tube lets the powder finish burning, adds velocity, and tightens standard deviation on a precision load. F-class .284s run long for that reason, and that is where I'd set my baseline.
A 24 to 26 inch barrel builds a handier hunting or field rifle and gives up only modest velocity, a fair trade if you are not chasing the last bit of ELR performance. The tables below assume the 28 inch recommended barrel.
Note: factory .284 Winchester ammunition is scarce, so the Bannerman load below is a boutique run rather than mass-production ammo, loaded with a Prvi Partizan 140-grain pointed soft point. Most .284 owners handload the cartridge, where the heavier match bullets and long barrels discussed above pay off. Confirm the listed velocity against your own chronograph.
Match Ammo Performance
Bannerman · 140 gr PSP Boat Tail $3.25/rd
| Range (yd) | Velocity (fps) | Elevation (mil) | Energy (ft-lb) | Windage (mil) |
|---|---|---|---|---|
| 0 | 2970 | -0.4 | 2742 | 0.4 |
| 100 | 2774 | 0.0 | 2392 | 0.2 |
| 200 | 2586 | -0.4 | 2079 | 0.4 |
| 300 | 2406 | -1.0 | 1799 | 0.6 |
| 400 | 2233 | -1.7 | 1549 | 0.9 |
| 500 | 2067 | -2.6 | 1328 | 1.1 |
| 600 | 1908 | -3.5 | 1132 | 1.4 |
| 700 | 1758 | -4.6 | 961 | 1.7 |
| 800 | 1617 | -5.7 | 813 | 2.0 |
| 900 | 1487 | -7.1 | 687 | 2.4 |
| 1000 | 1369 | -8.6 | 583 | 2.8 |
| 1100 | 1265 | -10.3 | 498 | 3.2 |
| 1200 | 1178 | -12.3 | 432 | 3.6 |
| 1300 | 1108 | -14.5 | 382 | 4.1 |
| 1400 | 1053 | -16.9 | 345 | 4.5 |
| 1500 | 1008 | -19.7 | 316 | 5.0 |
Muzzle velocity 2970 fps is the factory figure from a 28 in test barrel. Expect your own barrel to read a little differently. Velocity is color coded green supersonic, yellow transonic, red subsonic; treat transonic and subsonic rows as approximate.
Trajectory
FAQ
What barrel length and twist should I run?
For the long-range target role the cartridge suits best, run a 1:8 twist and a 28 inch barrel to stabilize and drive heavy 168 to 180 grain 7mm match bullets. A hunting build can use a 1:9 twist and a 24 inch barrel with lighter bullets.
Can you still buy factory .284 Winchester ammo?
Only sporadically. It is best treated as a handloader's cartridge, which is how most of its dedicated shooters run it. Brass is available from Nosler and others, and component bullets are plentiful.
Why the rebated rim?
So a wide, efficient case could fit a standard .473 inch bolt face and a short action. That packaging trick is the .284's signature, and it is what makes it such a good parent case for wildcats like the 6.5-284.
What is the .284 Winchester good for?
Long-range target shooting and F-class, efficient short-action hunting, and as a parent case for wildcatters. Its blend of capacity, efficiency, and accuracy is why it has outlived its modest commercial success.