Thread: Short barrel calibres?

The correct load data is in the books. The powders shown for a specific bullet weight are ranked fastest at the top to slowest at the bottom. Faster powders burn within the barrel while slower powders require full barrel length to burn completely, hence the ball of flame in short barrels. Faster powder loads that are safe in short barrels are perfectly safe in long barrels. The difference in velocity between short (18") and long (24") barrels is usually about 200-250 feet per second which really doesn't matter much inside of 300 metres. 16" barrels will lose another 100 fps, and barrels longer than 24" are for heavier bullets with a slow powder to develop good speed for long range shooting. Barrel length has no effect on accuracy subject to finding a good performing load.