Seating depth and pressure

YosemiteSam357 · August 24, 2004, 11:14 PM

I've worked up some loads using the COL specified in the loading manual. I recently picked up a Stoney Point OAL gauge and bullet comparator, and now know the max bullet length I can go, which is about .036" longer than what I tested. This will put the bullet .010" off the lands.

Do I need to go back and do pressure testing at various load levels to determine the max safe load for this COL, or can I assume that what was safe at my old seating depth will work at the new depth?

Thanks again,

-- Sam

shooter204 · August 25, 2004, 12:51 AM

i don't have the Stoney Point but have checked my seating depths for all my guns by placing bullets in shot cases and blackening them then backing them off the lands as you have. I usually shoot the rounds and then do a check for excessive pressure. I also use the Chrony and check that way.

If the bullet is making enough contact( not moving in the cases due to recoil) and is not showing signs of pressure, just figure out if you are receiving the velocities you desire.

mete · August 25, 2004, 06:43 AM

Seating the bullet out further will decrease the pressure so you're ok.

YosemiteSam357 · August 25, 2004, 10:41 AM

Thanks for the replies. In my learning about this subject I stumbled across the advice that having a bullet seated too long can cause pressure spikes as well as those seated too deep/short. In thinking about it, those that raise the warning are probably thinking about a bullet seated so long that it's right on the lands, where I can see it causing a pressue spike. I was just wondering if being .010" or even .005" off the lands will cause the same problem. It sounds like the answer is "no", but I thought I'd run it by the experts here first...

-- Sam

August 24, 2004, 11:14 PM	#1
YosemiteSam357 Senior Member Join Date: April 8, 2002 Location: Oregon, USA Posts: 231	Seating depth and pressure I've worked up some loads using the COL specified in the loading manual. I recently picked up a Stoney Point OAL gauge and bullet comparator, and now know the max bullet length I can go, which is about .036" longer than what I tested. This will put the bullet .010" off the lands. Do I need to go back and do pressure testing at various load levels to determine the max safe load for this COL, or can I assume that what was safe at my old seating depth will work at the new depth? Thanks again, -- Sam

August 25, 2004, 12:51 AM	#2
shooter204 Junior Member Join Date: August 23, 2004 Posts: 5	i don't have the Stoney Point but have checked my seating depths for all my guns by placing bullets in shot cases and blackening them then backing them off the lands as you have. I usually shoot the rounds and then do a check for excessive pressure. I also use the Chrony and check that way. If the bullet is making enough contact( not moving in the cases due to recoil) and is not showing signs of pressure, just figure out if you are receiving the velocities you desire.

August 25, 2004, 06:43 AM	#3
mete Senior Member Join Date: June 14, 2004 Location: NY State Posts: 6,575	Seating the bullet out further will decrease the pressure so you're ok.

August 25, 2004, 10:41 AM	#4
YosemiteSam357 Senior Member Join Date: April 8, 2002 Location: Oregon, USA Posts: 231	Thanks for the replies. In my learning about this subject I stumbled across the advice that having a bullet seated too long can cause pressure spikes as well as those seated too deep/short. In thinking about it, those that raise the warning are probably thinking about a bullet seated so long that it's right on the lands, where I can see it causing a pressue spike. I was just wondering if being .010" or even .005" off the lands will cause the same problem. It sounds like the answer is "no", but I thought I'd run it by the experts here first... -- Sam