Long-throating barrels can provide higher velocities

Shooting Industry, Feb, 1990 by William Schumaker

Meanwhile, keep in mind that no amount of long-throating can compensate for a powder that is too fast. I have on file a letter relating to IMR 4895 in the .300 Weatherby (yes 4895!). The reloader, being told by a so-called expert) that 4895 was similar to 4350, started slow and worked his way up. He didn't have to wait long, he blew the locking lugs off his rifle.

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