Finding the perfect OAL

catzor · June 21, 2010, 07:51 PM

I'm pretty new to reloading, but I'm really getting my feet wet with working up loads in my 9mm. It's a lot of fun making changes to the many variables and watching what the gun likes or doesn't. Now, my question is, what is the easiest way to find a gun's preferred OAL? It seems that once you discover that, you no longer have to fool with it and finding the correct charge becomes a much less confusing affair. I'm specifically working with a PT92 so if someone has done that work for me, feel free to give me your info so I can try to get that much closer to the perfect load.

Thanks!

zippy13 · June 22, 2010, 03:23 AM

Sorry, there is no one magic number for an individual gun, your optimum cartridge overall length will change with the different types of bullets you use. Unlike the single shot bench rest rifle, with your PT 92, you have magazine compatibility and feeding issues to deal with, too. Your best bet is to start with the CAOL listed for your specific bullet. My data show various optimum CAOLs from 0.990 to 1.169 (the SAAMI max).

WESHOOT2 · June 22, 2010, 05:25 AM

Using round nose bullets with no shoulder I use 1.140--1.155", with my 'go-to' length (the length my 'regular' seat die is set for) of 1.148".

FWIW, when selling commercially I used an OAL of 1.145".

wncchester · June 22, 2010, 11:41 AM

In my experience, any handgun ammo that will feed and chamber reliabily is "perfect." I can find that at home without firing a shot.

Within rational limits I've never seen any great difference in seating depth and accuracy for hand guns. And not a whole lot of difference with varying powder charges. Handguns aren't nearly as finicky to load for as long guns.

moxie · June 22, 2010, 01:34 PM

Go to the handloading section of the 1911 page and ask Niemi24s. He is the expert on this:
http://forum.m1911.org/forumdisplay.php?f=50

June 21, 2010, 07:51 PM	#1
catzor Senior Member Join Date: March 20, 2010 Location: Raleigh, NC Posts: 104	Finding the perfect OAL I'm pretty new to reloading, but I'm really getting my feet wet with working up loads in my 9mm. It's a lot of fun making changes to the many variables and watching what the gun likes or doesn't. Now, my question is, what is the easiest way to find a gun's preferred OAL? It seems that once you discover that, you no longer have to fool with it and finding the correct charge becomes a much less confusing affair. I'm specifically working with a PT92 so if someone has done that work for me, feel free to give me your info so I can try to get that much closer to the perfect load. Thanks!

June 22, 2010, 05:25 AM	#3
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	what I do Using round nose bullets with no shoulder I use 1.140--1.155", with my 'go-to' length (the length my 'regular' seat die is set for) of 1.148". FWIW, when selling commercially I used an OAL of 1.145". __________________ . "all my ammo is mostly retired factory ammo"

June 22, 2010, 01:34 PM	#5
moxie Senior Member Join Date: October 17, 2006 Location: TX Posts: 513	Go to the handloading section of the 1911 page and ask Niemi24s. He is the expert on this: http://forum.m1911.org/forumdisplay.php?f=50 __________________ If you want to shoot...shoot...don't talk! Tuco USAF Munitions 1969-1992 RVN 1972-1973

June 22, 2010, 03:23 AM	#2
zippy13 Senior Member Join Date: August 23, 2008 Location: SoCal Posts: 6,442	Sorry, there is no one magic number for an individual gun, your optimum cartridge overall length will change with the different types of bullets you use. Unlike the single shot bench rest rifle, with your PT 92, you have magazine compatibility and feeding issues to deal with, too. Your best bet is to start with the CAOL listed for your specific bullet. My data show various optimum CAOLs from 0.990 to 1.169 (the SAAMI max).

June 22, 2010, 11:41 AM	#4
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	In my experience, any handgun ammo that will feed and chamber reliabily is "perfect." I can find that at home without firing a shot. Within rational limits I've never seen any great difference in seating depth and accuracy for hand guns. And not a whole lot of difference with varying powder charges. Handguns aren't nearly as finicky to load for as long guns.