weatherby 300 mag and COAL

Early Cuyler

Gunny Sergeant
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Mar 3, 2011
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So my dad has an elk gun in 300wby mag and I figured I would reload some shells for him. However when I use my Hornady OAL gage (sliding plunged forward gently until the bullet touches the lands) I get a COAL of 3.860" with the bullet barely inserted into the case. From reading here it seems a .02" offset is a good starting point but that doesn't resolve that issue.

I also measured the magazine length at 3.750" (limiting factor) but that is still more than .2" longer than factory loads (3.546"). I am using the same bullet to measure as the factory loads.

So my question is this: why is there such a large disparity between the magazine and factory load lengths compared to the measured OAL of the rifle? Won't this jump cause a drop in accuracy? Or am I going about this all wrong?

Thanks in advance and hope everyone has a happy thanksgiving.
 

rg1

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Dec 6, 2004
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Re: weatherby 300 mag and COAL

Weatherby rifles in particular have a very long freebore. Seating to touch the lands or get close is generally not possible as like you said the bullet isn't seated deep enough in the case. I load to 3.560" for 165, 180, and 200 grain bullets. The long freebore is to reduce pressure. When using Federal, Remington, or other non-Weatherby cases reduce loading levels as Fed and Rem have less case capacity. Just load to bullet company recommended length or Weatherby recommended lengths.
 

Early Cuyler

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Mar 3, 2011
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WB, GA
Re: weatherby 300 mag and COAL

thanks, rg1. I was planning on loading to just under the BDL mag length (~3.740") but I'll go with the factory length.
 

LtDan47

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Sep 20, 2011
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Sacramento,CA
Re: weatherby 300 mag and COAL

Hey I used to have a 300 WthBy many years ago, I was going through some boxes in my garage and found 40 rounds of cleaned wetherby original brass that I had with the rifle. Most of it is once fired maybe twice fired and deprimed. I have no use for it I would give it to you for the cost of shipping. Let me know email me at dcalhoun15@comcast.net..... I used to use 180 gr Nosler Partitions for deer, what a shoulder cannon whew!