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wncchester · July 19, 2009, 05:16 PM

"If I measure a factory Winchester 9mm 115gr FMJ, I get a 1.163" COL.

My Hornady page in One Book calls for my reload to be 1.100" COL.
My Hodgdon Annual calls for a 1.169" COL for a 115gr FMJ.
My Lyman Pistol and Revolver Handbook calls for 1.105" for a 100gr FMJ.
My Lyman 49th calls for 1.115" OAL for a 147gr TMJ

When I set a 1.100 alongside a Winchester factory ammo, it looks way, way short.

What is the deal on this and what do I do??? My books all show a 1.169" as the maximum OAL (in the picture diagram on top of 9mm Luger page in Lyman 49th)."

Does kinda make a man wonder if OAL is as much a "science" as some make it to be, doesn't it?

It isn't science. You need to understand only one thing about the book OAL numbers; what you see is what the manual makers used to develop their data. But, your firearm isn't theirs and what works for them may well not work so well for you. Bottom line, and no matter what anyone says, the book OAL is no more a fixed figure for everyone than are the powder charges the books present.

Load a dummy round with any bullet you choose. Find a seating depth that allows it to manually work through your firearm and chamber reliably. Then pick a proper powder for that bullet weight, start low and work up until you reach max OR experience some kind of over pressure sign.

July 19, 2009, 05:16 PM	#10
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"If I measure a factory Winchester 9mm 115gr FMJ, I get a 1.163" COL. My Hornady page in One Book calls for my reload to be 1.100" COL. My Hodgdon Annual calls for a 1.169" COL for a 115gr FMJ. My Lyman Pistol and Revolver Handbook calls for 1.105" for a 100gr FMJ. My Lyman 49th calls for 1.115" OAL for a 147gr TMJ When I set a 1.100 alongside a Winchester factory ammo, it looks way, way short. What is the deal on this and what do I do??? My books all show a 1.169" as the maximum OAL (in the picture diagram on top of 9mm Luger page in Lyman 49th)." Does kinda make a man wonder if OAL is as much a "science" as some make it to be, doesn't it? It isn't science. You need to understand only one thing about the book OAL numbers; what you see is what the manual makers used to develop their data. But, your firearm isn't theirs and what works for them may well not work so well for you. Bottom line, and no matter what anyone says, the book OAL is no more a fixed figure for everyone than are the powder charges the books present. Load a dummy round with any bullet you choose. Find a seating depth that allows it to manually work through your firearm and chamber reliably. Then pick a proper powder for that bullet weight, start low and work up until you reach max OR experience some kind of over pressure sign.