[Bob72]

Just an idle question that I could use an answer on. The OAL for 90 grain jacketed bullet in ,243 is 2.650. The bullet length on a factory round is 2.618.. not a big difference but below the OAL in the book. (Lee's) WHY? and thanks for the usual pithy, pertinent answers in advance. :)

[BYJO4]

OAL can vary on for different reasons such as make of bullet or style of bullet.
The max OAL is generally based on what will chamber in virtually all guns.

[gamestalker]

First of all, factory ammunition is manufactured to a one size fits all standard and isn't a good example of what may perform best from a particular rifle. This is what brought me into the whole reloading hobby over 30 yrs. ago the ability to custom fit my ammunition to the action and chamber I'm shooting it from.

Published OAL's are no more than just a refrence point by which to start from. Geeting the brass properly formed to the head space of a given rifle, seating to the most accurate OAL, and finding the powder charge that does what your desiring is what reloading is based on. When I seat a bullet for a high powered bolt action, I start long and back off until I find the most accurate OAL, which is commonly just off the lands or touching slightly.
GS

[steve4102]

OAL is not manual specific, it is firearm specific. Some manuals do not even list the OAL for rounds tested.

From Western Powders.

SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must be seen as a
guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of the barrel, 3)
ogive or profile of the projectile and 4) position of cannelure or crimp groove.

[ranger335v]

At one time few manuals gave any OAL at all. In an effort to help, loading manuals eventually started listing OALs but have created more confusion than help.

The books that list an OAL are only telling you the length they used to develop their data. That listed book OAL is no more a law, or even recommendation, than the charges they list.

[rcmodel]

Lee's manual doesn't even tell you what brand, shape, or type of 90 grain bullet they are talking about.

You need a better manual that is bullet specific, or at least mentions what bullet design the data is for.

There is a huge difference in bullet length and bearing surface between a 90 grain HP-FB and a 90 grain Ballistic-Tip boat tail for instance.

rc

[243winxb]

The COL for the 243 Win. is 2.710" maximum & 2.540" minimum by SAAMI standards. See cartridge & chamber drawings here> http://www.saami.org/PubResources/CC_Drawings/Rifle/243%20Winchester.pdf

[steve4102]

Which has little to do with the handloader, see post #4.

[Bob72]

Well I am certainly learning which is why I came here in the first place.. Thanks.:)