Reloading 303 British
| 303 British Dimensions | |
|---|---|
| Bullet Diameter (inches) | 0.311 |
| Max Cartridge Length (inches) | 3.05 |
| Max Case Length (inches) | 2.22 |
| Case Trim Length (inches) | 2.12 |
303 British Cases and Case Life
This cartridge headspaces on the rim which allowed the designers to include a fair amount of slop between the shoulder area of the case and the wall of the chamber.
This was done to ensure that dirty or corroded rounds would still chamber.
Upon firing the brass case expands to fill the chamber pushing the shoulder of the cartridge case forward about 1/16th of an inch.
What this means to someone reloading for 303 British is that when these cartridge cases are full length resized repeatedly,
the metal on the shoulder is worked severely resulting in a short case life.
When 303 British cases are to be fired in the same rifle then the ideal way to extract the most life possible out of the brass is to only size the neck of the case using a neck sizing die. As I have don't have a neck sizing die for 303 British, I have found that it is possible accomplish the same thing by partial length resizing using a full length resizing die. Since the 303 british cartridge uses such a strongly tapered case, backing out the sizing die a couple of turns or about 1/8 inch will size the case neck without setting the shoulder back provided that rifle in which the cases were fired does not have a particularly oversized chamber.
Some things to note about the loading data on this page;
- I am only relating my personal experience with the firearms and equipment that I own and that I am not making any loading recommendations. If you use the loading data here, you do so at your own risk.
- I never use Large Pistol Primers in place of Large Rifle primers for a variety of safety and practical concerns.
- I have never found it necessary to use fillers such as cream of wheat, polyfill or toilet paper to position the powder against the flash hole in a cartridge case.
- Unless stated otherwise, muzzle velocities listed on this page are from my own test data.
| 303 British | |
|---|---|
| Bullet | 156 grain Lead Spire Point Gas Check, LEE C312-155-2R |
| Powder | 23.0 grains IMR 4227 |
| Primer | CCI #34 |
| Cartridge Case | Prvi Partizan |
| Firearm | Lee Enfield Rifle No.4 Mark 1 |
| Barrel Length | 25.2 inches |
| Avg Muzzle Velocity | 1849 feet per second |
Rear sight set to 500 yard setting to hit at 100 yards. Some vertical stringing
| 303 British | |
|---|---|
| Bullet | 152 grain Lead Spire Point plain base, LEE C312-155-2R |
| Powder | 6.1 grains Alliant Bullseye |
| Primer | CCI 200 |
| Cartridge Case | Remington |
| Firearm | Lee Enfield Rifle No.4 Mark 1 |
| Barrel Length | 25.2 inches |
| Avg Muzzle Velocity | 1079 feet per second |
Some of my other cast bullet handloads for 303 British can be found on the Reduced Power Rifle loads page.
Harris, C.E. "DON'T OVERLOOK THE LEE-ENFIELD" American Rifleman July 1993 p. 46-49, 74-75
Harris, C.E. ""Handloading The .303 British" American Rifleman March 1993 p. 16, 18-20