Lee Loader

GasGuzzler wrote:Since books don't agree with each other there is always more than one "right".

I agree with that gas. .
First off the books overall length are designated for specific bullets that they publish and then an overall maximum length if I understand correctly. . If you're using an unpublished bullet I'm sure you'll be somewhere in the range but if I can measure and get close then I'm feeling ahead of the game

Looked at the DIY measuring thread, and it's just a method we've been using for decades. In my opinion though for pistol reloading it is an exercise in futility; for 9mm it has little use. For rifle reloading, "chasing the lands" has some use, but normally the last procedure in finding accurate loads, components and powders and powder charges way out weigh the need for finding an accurate handload, BTDT. I have 4, 9mm pistols and for many years have been able to get by with "book OAL and plunk test" method, quite well and get good (for 9mm P) accuracy even for "off brand" shaped bullets. My newest 9mm pistol does have a shorter chamber and one specific bullet that works well in the other 3, needs to be .005" deeper seated to plunk easily. Ruger, FMK, and Tokerev all use the same OAL with the same bullets, but my Masada has a shorter chamber, which I found with the plunk test. (Nosler 124 gr. JHP)...

Opposite hear.

I found a great amount of accuracy in 9X19 by going over OAL and over by a small amount in powder.

Still say there is no "book OAL" when the books don't agree.

My nickle .
Bullet shape plays a role here sometimes a big role . A given caliber of a given weight can be in some cases a lot longer or shorter for profile . A Hornady 150 gr BTSP for example is about the same length as the 180 RN . In 9mm/38/357 we have 3-4 different RN profiles , TC , SWC , RN , and RNFP . If we presume a particular magazine length and load at minus .05 of that to ensure function then we have a situation where a RNFP with say a .280 meplat at 130 gr has much less bullet in the case than a TC with a .180 meplat . If we go to a SWC with a 356 top band and a square nose at .250 meplat and .280 base at the top band and .250 long there's even more bullet in the case . A single radius bullet vs a double radius bullet enters the same game and both with fall somewhere between the TC and SWC for case intrusion . I don't have available examples of each for comparison unfortunately . In the case of a full WC seated nose out vs flush a standard load in a 38 Special can go from a mild well under max load to a +P+ pushing the limits in a +P gun maybe best suited for a 357 . That is a full .1 change in OAL but also in case intrusion .
The same thing happens with the change in nose dia of our cartridge that is limited by magazine length . If a bullet is .05 longer and .05 deeper in the case it's not really a big deal if the load is say a 15 kpsi 9mm load even if it jumps the pressure 10kpsi it's still well under the 35kpsi limit . Now if it's a 30 kpsi load it becomes a whole new bucket of snakes because it starts higher and jumps higher so that little 8kpsi bump is more like a 12 kpsi bump assuming that the powder stays stable and doesn't go out on its own pressure excursion also . A quality well balanced modern 9mm will survive a mag or 2 of 40 kpsi and even spikes to 48 kpsi but you might convert a 1908 Luger to a box of broken parts with with just 1 48 kpsi opps .

End suggestion . Take the best closest data available and start at the bottom . Most data is designed around minimum magazine length plus maximum defect for optimal feeding in everything . As a hand loader we have the ability to load for our shortest mag that might be a 1/10" longer than the test data gun . Start low , work up , be safe .

Now in revolvers it's the same and not 45 Colts have a 1.600 OAL and most cylinders are at least 1.610" but there are some as long as 1.75 , the Ruger I had was 1.962 including the nose extension and spur at the rear that was about half a rim thickness taller than the rims . A spare ACP cyl just measured at 1.755 face to face without some bizarrely long heavy bullet you can't load a 45 ACP that long but a 300-350 45 Colts is no problem . I just happened to have a dummy for feed testing in an M92' at 1.679 and if only for the above mentioned RBH it could go 1.70 w/o issue .

This probably only adds to the confusion about OAL . When in doubt go with book or manufacturers data . Where a conflict exists add another book or other data source . If 66% don't agree average the disagreement numbers and start there with a start load .

I shoot every load to see group trends and go .1-2gr over clean cycling , more only if groups are continuing to close and there are no indicators of pressure and I'm under the middle max load . I have had 1 in 70 or so encountered and loaded for metallic case guns that shot a max load best .

I don't call "overcharged" over max when the OAL has been lengthened to match the gun dimensions.