col lenght for 308?

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tob1onone

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lee manual say's 2.8 inch col for 150 gr bullets . If I measure factory ammo with same 150grs bullet I get 2.7... what lenght should I use? I'm using h4895, win 308 fc case,and wnchester 150gr.pp thanks ..:confused:
 
could it be that the factory loads are playing it safe so that the .308 will chamber in rifles that have little or no throat? I am just asking as I know that factory stuff has to fit ALL rifles, where as reloaded stuff only has to fit YOUR rifle.
 
Factory ammo has to be no longer than 2.80" to conform with SAAMI and CIP. Many polls of BR shooters indicate best .308 Win accuracy is achieved with zero jump in relation to rifling so adjust OAL accordingly. Having said that, best accuracy has to be determined by testing OAL in relation to rifling for your rifle.

Regards,

Peter
 
tob1onone said:
lee manual say's 2.8 inch col for 150 gr bullets . If I measure factory ammo with same 150grs bullet I get 2.7... what lenght should I use? I'm using h4895, win 308 fc case,and wnchester 150gr.pp thanks ..:confused:
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Check on Hodgdon's data page, you will find that it also calls for an OAL of 2.80". You can't just measure factory ammo, as they are not using the same powder, case, primer etc. You need to go with the data for your load. If it says 2.8, go with it. Always use more than one source for your info as well, you mentioned your Lee manual, well check Hodgdon's data, and maybe see if the bullet your using has some info on this load as well. Hodgdon's web page has a large amount of data you can use, and it's free! Cheers!
 
sgt.rock said:
could it be that the factory loads are playing it safe so that the .308 will chamber in rifles that have little or no throat? I am just asking as I know that factory stuff has to fit ALL rifles, where as reloaded stuff only has to fit YOUR rifle.
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Not just .308 - My once-fired Hornady LeveRevolution .45-70 brass is well under max case length making the cannelure on the 350 grain RN's I like useless for crimping into, to remain at minimum COL.
 
You can set the bullet out to your lands or 10 thousand back off of them, 2.7 inches will fit in all magazines and 2.8 may not. really depends if you want to single load or load the mag. Measure you maximum oal by pushing a bullet into the lands with a pencil, insert a cleaning rod down the barrel till it touches the bullet and make a mark on the rod. close the bolt and insert the cleaning rod till it touches the bolt and mark this as well. measure between these two marks and you will have the maximum aol for your particular rifle.
 
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