Author Topic: Cartridge OAL effect on pressure (Read 381 times)

lilabner · « **on:** January 08, 2005, 03:08:29 AM »

When loading so the bullet is nearly touching the barrel lands, should the powder charge be reduced?

clodbuster · « **Reply #1 on:** January 08, 2005, 03:38:37 AM »

Depends on what you mean by "nearly touching the lands". Touching is touching but is .020 inch nearly touching? I would reduce the charge if the bullet is any closer than .020. I wouldn't worry about reducing it if the bullet is .030 or more.

rbwillnj · « **Reply #2 on:** January 08, 2005, 05:02:46 AM »

Well, I am not a ballistics expert, but everything I have read says that minimum OALs are to prevent excess pressure, and Maximum OALs are to insure proper function of the firearm. That is, if you seat the bullet too deep, you can get excess pressure, and if you leave it out too far, you can get jams.

There are a lot people who think you should leave the bullet out pretty far to minimize the Jump to the rifling.

Lone Star · « **Reply #3 on:** January 08, 2005, 03:04:53 PM »

One of the best explanations on this topic is in the front of every Hornady Manual published since 1973.

stork · « **Reply #4 on:** January 09, 2005, 07:11:45 AM »

yup go get one of Hornady's manuals and it will explain how COL has an effect on pressure than most of us can.