Thread: .303 reloads

Originally Posted by Tasbay

I now have some redundant 7.62x39 (THANKS JACINDA ) after some searching it seems to reload this to 303 British all that needs to be done is size and prime the 303 case, pull the bullet and powder from the 7.62x39 and dump it in the 303 case. I would have assumed there would be air space between powder and bullet due to different case sizes but this seems to not be a problem. Any comments advice welcome.

It sounds simple but this approach can be problematic. The projectile is fine its the powder where problems can begin.
The russian round is designed for a shorter barrel than the 25 inch enfield so the powder is reasonably fast think adi 2207 and is 25-28 grains. The case is full.
The 303 uses 40 -44 grains of 2206h for a similar weight 125 gr pill and the case us full.
Using a smaller charge of fast powder in a larger case can cause serious pressure issues, as the powder lays flat exposing a larger than normal surface area so it can ignite in mass not progressivly and cause a massive pressure spike.
It is not safe to transfer load data from one case to another as the dynamics of ignition are case size dependent.