Casting rifle bullets is more demanding than pistol casting but deeply rewarding. The .308 Winchester and other 30 caliber cartridges — 30-06, .30 Carbine, 300 Blackout — all use the same .308" bullet diameter. With the right alloy, gas checks, and technique, cast bullets in these cartridges deliver excellent accuracy at a fraction of the cost of jacketed projectiles.
At rifle velocities above about 1,500 fps, the hot powder gases erode the base of a cast bullet, causing gas cutting, leading, and poor accuracy. A gas check — a small copper cup crimped to the bullet base — prevents this by sealing the base against the gases. For any .308 load above 1,400 fps, use gas check bullets. Below that velocity (such as subsonic 300 Blackout), plain base bullets are fine.
| Cartridge / Load | Velocity | Minimum Alloy Hardness |
|---|---|---|
| .30 Carbine standard | ~1,900 fps | Lyman #2 (15 BHN) + gas check |
| 300 Blackout subsonic | ~1,000 fps | Wheel weight, plain base |
| 300 Blackout supersonic | ~2,100 fps | Hard alloy + gas check |
| .308 Win reduced load | 1,400–1,700 fps | Wheel weight + gas check |
| .308 Win standard | 2,000–2,500 fps | Hard alloy (18+ BHN) + gas check |
| 30-06 standard | 2,200–2,700 fps | Linotype or equivalent + gas check |
Important: Cast bullets in full-power .308 Winchester loads are typically limited to around 1,800–2,000 fps before leading becomes unmanageable, even with hard alloys and gas checks. For 2,400+ fps loads, jacketed bullets are generally more practical. Many cast bullet rifle shooters use reduced loads intentionally for economical target practice.
Many .308 Winchester shooters use cast bullets for economical practice at 100–200 yards, running loads at 1,400–1,700 fps. Accuracy is often excellent — 1–2 MOA is achievable with careful load development — and the cost per round is dramatically lower than jacketed factory ammunition.
The 300 Blackout subsonic niche is ideal for cast bullets. At 1,000 fps, even a plain-base cast bullet works perfectly. A 220 grain cast bullet over a small powder charge produces suppressor-friendly loads at minimal cost.
The 30-06 has a long history with cast bullets. At reduced velocities (1,600–1,800 fps), a well-cast bullet with gas check delivers good hunting performance on deer-sized game at modest ranges, and target accuracy at the range.
The M2R Automatic Casting Machine handles rifle calibers including 30 caliber. High output, consistent quality, built for serious volume.
View the M2R MachineYes, with some considerations. Gas-operated semi-autos may need an adjustable gas block to function reliably with reduced cast bullet loads. At full-power velocities, leading can foul the gas system. Many AR-10 cast bullet shooters run reduced loads in the 1,600–1,800 fps range for reliable function and manageable leading.
Gas checks are typically crimped to the bullet base during the sizing process using a gas check seating die that's part of most lubricator-sizer setups. You don't need a separate crimper — the sizer handles it in one step.
With good load development, 1–2 MOA at 100 yards is realistic. Some rifles and cast bullet combinations deliver sub-MOA groups. Accuracy depends heavily on bullet fit to the bore, alloy consistency, and load development.