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300 Win Mag COL?

19 May 2020
@ 01:09 pm (GMT)

Victorius Kokaram

I have been trying to figure out what is the deviation for the COAL. Hodgdon says the C.O.L for a 300 Win Mag 200 GR NOS AB is 3.340" but what I cannot seem to find info on is what deviation is accepted. I normally load 9mm but I am trying for the first time 300 Win Mag loading (not reloading, I am buy new cartridge cases) unprimed.


22 May 2020
@ 09:06 pm (GMT)

Chris Murphy

Re: 300 Win Mag COL?
Your rifle will tell you the col either the mag length or the throat length ( bullet touching the lands)
24 May 2020
@ 08:50 am (GMT)

Nathan Foster

Re: 300 Win Mag COL?
Hi Victorius, the .300 Win mag rifles vary a great deal from chamber to chamber. You will need to determine the actual max OAL for your rifle, rather than relying on a book.

Books do not tell you the max OAL, they tell you the max length of the ammunition that was tested, generally in keeping with SAAMI spec ammunition. This has nothing to do with the chamber of a rifle, even when companies like Nosler or Hodgdon use the terms MAX OAL, MAX COAL or MAX COL on their load data page. What they are saying, is that 3.340" is the maximum they loaded to, in keeping with SAAMI specified tolerances.

You can find out how to determine your true max OAL via one of the methods in my reloading book.

If you are shooting a Tikka rifle, then you simply cannot get close to the lands without single feeding. Instead, simply seat to 85mm (3.346") as this is the absolute maximum your magazine will allow. In fact you may need to seat at 84.5mm to obtain smooth feeding. There is no need to take a max reading of the chamber if you are seating less than 85mm.


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