velocity channge in various barrel lengths

[scott law]

The loading in my hornady manual shows data based on a barrel length of 14.5inches . How much. Does this data change as barrel length is changed ?? For instance I own a alexander arms upper ,20 inches long . May be a dumb question , but can I use this data to load for my 20 inch barrel without generating too much pressures for my upper . Once again a 14.5 inch alexander arms gun was used to show the loads and velocities in hornady manual . Hope someone can help , just want to be sure not to cause damage to my new upper . Thanks in advance.

[Taylormade]

The barrel length only effects velocity not pressure. The amount of powder you use will effect pressure.

[JASmith]

You can use the chart here to get a good approximation of the velocity in your barrel http://www.65grendel.com/forum/showt...h-and-Velocity.

Or you can look in the 6.5 Grendel Reloading Handbook for a similar chart.