Reliable Lyman cast bullet reloading data can be found in the Lyman Cast Bullet Handbook (including the 3rd and 4th Editions) and the standard Lyman Reloading Handbooks (such as the 49th and 50th Editions). Cast bullet specific data matters because lead alloy bullets generate less bore friction and seal differently than copper jacketed bullets, resulting in entirely different pressure curves. This data differs from jacketed bullet data because using jacketed load charges with cast bullets can cause severe barrel leading or compromise the structural integrity of the lead projectile. Published Lyman cast data typically covers common bullet weights ranging from 120 grain 9mm bullets to 200 grain .45 ACP semi-wadcutters and 170 grain .30 caliber rifle bullets. Selecting the correct powder is particularly important to prevent base melting, maintain proper obturation (expansion), and ensure the gas check performs effectively at higher velocities.
Lyman Cast Bullet Reloading Data
| Bullet / Mould # | Bullet Weight | Powder | Published Starting Load | Published Maximum Load | Published Velocity | Barrel Length / Firearm | Source |
| Lyman #356242 (RN) | 120 grain | Bullseye | 3.4 gr | 4.2 gr | 1,065 fps | 4 inch / Pistol | Lyman Cast Bullet Handbook |
| Lyman #358156 (SWC GC) | 158 grain | H110 | 11.6 gr | 15.7 gr | 1,350 fps | Vented Test Barrel | Lyman Cast Bullet Handbook 3rd Ed |
| Lyman #358156 (SWC GC) | 158 grain | 2400 | 10.9 gr | 14.0 gr | 1,350 fps | 6 inch / Revolver | Lyman Cast Bullet Handbook |
| Lyman #452460 (SWC) | 200 grain | Bullseye | 4.0 gr | 5.0 gr | 900 fps | 5 inch / 1911 | Lyman Cast Bullet Handbook |
| Lyman #452460 (SWC) | 200 grain | SR-7625 | 5.0 gr | 6.5 gr | 900 fps | 5 inch / 1911 | Lyman Cast Bullet Handbook |
| Lyman #311291 (RN GC) | 169 grain | Unique | 7.0 gr | 10.6 gr | 1,568 fps | 24 inch / Rifle | Lyman Cast Bullet Handbook |
| Lyman #311291 (RN GC) | 169 grain | Red Dot | 6.5 gr | 8.5 gr | 1,363 fps | 24 inch / Rifle | Lyman Cast Bullet Handbook |
| Lyman #311041 (FP GC) | 173 grain | SR-4756 | 8.0 gr | 13.0 gr | 1,450 fps | 24 inch / Rifle | Lyman Cast Bullet Handbook 4th Ed |
Understanding Lyman Cast Bullet Reloading Data
To safely use the data provided above, it is vital to understand the terminology and testing variables used by Lyman.
- Starting load: The lowest tested powder charge recommended by Lyman. For cast bullets, dropping below this can cause the bullet to fail to obturate (expand) properly, leading to gas blow by and barrel leading.
- Maximum published load: The absolute upper limit tested by the manufacturer. Pushing a cast bullet past this limit will often exceed the physical limits of the lead alloy, stripping the rifling and severely leading the barrel.
- Velocity: The speed of the projectile measured in feet per second (fps) near the muzzle.
- Pressure: The chamber pressure generated upon firing. Cast bullets generally produce less pressure than jacketed bullets of the exact same weight because lead creates less friction against the steel barrel.
- Bullet / Mould Number: Lyman identifies its load data based on the specific mould block number (e.g., #311041 for a .30 caliber 173 grain flat point).
- Powder: The specific chemical propellant. Cast bullet data frequently utilizes faster burning pistol and shotgun powders even in rifle cartridges.
- Barrel length: The length of the test barrel used to record the published velocity.
- Cartridge overall length: The total length of the loaded round. Seating a cast bullet too deep compresses the powder space and dangerously increases pressure.
Lyman Cast Bullet Calibers And Bullet Weights
Lyman publishes cast bullet load data for nearly every modern centerfire cartridge. The most commonly referenced data focuses on historic handgun cartridges and military rifle calibers.
- 9mm Luger (120 grain): The Lyman #356242 round nose mould is the standard for 9mm cast reloading. Because the 9mm operates at high pressure, alloy hardness is critical to prevent leading.
- .38 Special and .357 Magnum (158 to 170 grain):Elmer Keith’s famous designs, such as the #358429 (170 grain) and the #358156 (158 grain gas check), are heavily documented in Lyman manuals. These bullets are proven for both target shooting and hunting.
- .45 ACP (200 grain): The Lyman #452460 semi-wadcutter is legendary for bullseye competition. Data for this bullet relies heavily on fast burning powders to achieve optimal target velocities around 800 to 900 fps.
- .30-30 Winchester and .30-06 Springfield (169 to 173 grain): The #311291 round nose and #311041 flat point are the gold standards for .30 caliber rifles. Published data heavily supports using these bullets with gas checks for deer hunting or reduced target practice.
Lyman Cast Bullet Powder Selection
Powder selection for cast bullets is fundamentally different than for jacketed bullets. Lyman data heavily favors powders that ignite easily and burn completely at lower pressures.
For handguns, fast burning flake powders like Bullseye, Red Dot, and Unique are universally listed in the Lyman Cast Bullet Handbook. For magnum handgun loads utilizing gas checked lead bullets, 2400 and H110 are heavily documented.
For rifle cartridges like the .30-06 and .30-30, Lyman data often substitutes traditional slow burning rifle powders with medium to fast pistol powders (like Unique or SR-4759) to create highly accurate, low recoil target loads. Using standard jacketed rifle data (like full charges of IMR 4350) behind a cast bullet without consulting a Lyman manual will typically drive the bullet too fast, melting the base and destroying accuracy.
Cast Bullets vs Jacketed Bullets Reloading Data
You cannot safely swap jacketed bullet load data for cast bullets, nor can you use cast bullet data for jacketed bullets without verification.
Because lead is softer and more lubricious than a copper jacket, a cast bullet slides down the barrel with less resistance. If you use a published starting load meant for a cast bullet behind a jacketed bullet, the copper jacket may experience too much friction and stick inside the bore (a squib load).
Conversely, if you use a maximum jacketed bullet load behind a cast lead bullet, the extreme pressure and heat will melt the base of the bullet, blow molten lead past the sides of the projectile, and leave severe lead fouling in the rifling. Lyman publishes dedicated cast bullet data to ensure the pressure curve matches the specific hardness of the lead alloy being fired.
Bullet Alloys, Sizing, And Gas Checks
Lyman load data specifies the exact alloy used during testing, most commonly Lyman #2 Alloy. If a reloader uses pure lead, which is much softer, the bullet will strip the rifling at the maximum published velocities. Using a harder alloy, such as Linotype, allows the bullet to handle higher pressures without deforming.
Sizing diameter is also critical. Lyman recommends sizing cast bullets .001 to .002 inches larger than the actual groove diameter of the barrel. For example, a .30-06 rifle with a .308 inch groove diameter requires a cast bullet sized to .309 or .310 inches to properly seal the bore and prevent hot gases from melting the sides of the bullet.
Gas checks are small copper cups crimped onto the base of specific cast bullets (like the #358156 or #311041). The Lyman Cast Bullet Handbook provides separate data for plain base bullets and gas checked bullets. A gas check protects the base of the lead bullet from the heat of the powder charge, allowing the reloader to safely use higher powder charges and achieve velocities closer to jacketed ammunition.
Lyman Cast Bullet Velocity From Published Data
Velocities achieved with cast bullets are generally lower than jacketed bullets to prevent leading. This comparison highlights publisher tested velocities from the Lyman Cast Bullet Handbook.
| Bullet | Bullet Weight | Powder | Published Load (Max) | Muzzle Velocity | Barrel Length / Firearm | Source |
| Lyman #452460 | 200 grain | Bullseye | 5.0 gr | 900 fps | 5 inch / 1911 | Lyman Cast Bullet Handbook |
| Lyman #358156 | 158 grain | H110 | 15.7 gr | 1,350 fps | Vented Test Barrel | Lyman Cast Bullet Handbook 3rd Ed |
| Lyman #311291 | 169 grain | SR-4759 | 18.5 gr | 1,862 fps | 24 inch / Rifle | Lyman Cast Bullet Handbook |
| Lyman #311041 | 173 grain | SR-4756 | 13.0 gr | 1,450 fps | 24 inch / Rifle | Lyman Cast Bullet Handbook 4th Ed |
Pressure, Leading, And Safety
Leading occurs when lead deposits are left behind in the rifling grooves of the barrel. While minor leading affects accuracy, severe leading dangerously increases chamber pressure because it constricts the bore diameter for subsequent shots.
Lyman cast bullet data is strictly engineered to balance chamber pressure with alloy hardness to prevent leading. If a load is too light, the bullet will not expand to seal the bore, and hot gas will cut past the bullet, melting the lead. If the load is too hot, the pressure will simply overwhelm the alloy. You must follow Lyman’s starting and maximum loads exactly, and ensure your bullets are properly lubricated with a high quality bullet lube before firing.
Manufacturer Data vs Independent Testing
When reviewing Lyman cast bullet reloading information, it is critical to separate official sources from secondary reports.
- Manufacturer published reloading data: The Lyman Cast Bullet Handbook utilizes laboratory pressure barrels to measure exact pressure curves. Their starting and maximum loads are scientifically verified to remain under SAAMI pressure specifications while optimizing cast bullet performance.
- Independent chronograph testing: User submitted load reports on forums often lack pressure testing equipment and rely on visual primer inspections, which are unreliable for low pressure cast loads. Never substitute a forum recipe for an official published Lyman load.
Best Sources For Lyman Cast Bullet Reloading Data
The strongest current sources for Lyman specific cast bullet load data include:
- Lyman Cast Bullet Handbook (3rd and 4th Editions): The absolute gold standard for cast bullet data. The 4th Edition includes modern powders, while the 3rd Edition contains older, classic powder formulations.
- Lyman 50th and 51st Edition Reloading Handbooks: While not exclusively dedicated to cast bullets, Lyman’s standard reloading manuals always feature extensive cast bullet data alongside their jacketed data.
- Powder Manufacturer Data: Companies like Western Powders, Hodgdon, and Alliant frequently reference specific Lyman mould numbers (e.g., #358156 or #452460) in their online data centers.
FAQs
Where can I find Lyman cast bullet reloading data?
Authoritative Lyman cast bullet reloading data can be found in the Lyman Cast Bullet Handbook (3rd and 4th Editions) and the standard Lyman Reloading Handbooks.
Is cast bullet load data different from jacketed load data?
Yes. Cast bullets generate less bore friction than jacketed bullets, resulting in different pressure curves. You cannot safely swap load data between cast and jacketed projectiles.
What is the Lyman #452460 bullet used for?
The Lyman #452460 is a highly popular 200 grain semi-wadcutter bullet designed for the .45 ACP, heavily utilized in bullseye target competition.
What powders are suitable for cast bullet rifle loads according to Lyman data?
For rifle cartridges like the .30-30 and .30-06, Lyman frequently publishes cast bullet data using fast to medium burning powders such as Unique, Red Dot, SR-4759, and 2400 to achieve accurate, low recoil loads.
Why do some Lyman cast bullets use gas checks?
Gas checks are copper cups placed on the base of the lead bullet to protect it from the extreme heat of the burning powder. This allows reloaders to safely drive the cast bullet to higher velocities without melting the base or severely leading the barrel.
Does alloy hardness matter when using Lyman load data?
Yes. Lyman load data is typically tested using Lyman #2 Alloy. Using an alloy that is significantly softer, like pure lead, can result in the bullet stripping the rifling and severely fouling the barrel at published maximum pressures.
Can I use jacketed bullet load data for a cast bullet of the same weight?
No. Using maximum jacketed bullet load data for a cast bullet will generally drive the lead projectile far too fast, resulting in severe barrel leading and a total loss of accuracy. You must use dedicated cast bullet data.