Made a boo boo

K

Kazman1960

CGN Regular
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Location
Timmins Ontario
I just finished loading 10 rounds for a test on my 308 , when i double checked ( after i was done instead of before or during ) it appears i used Magnum primers instead of Large rifle .
Are these safe to use or should i just pull the bullets and dr prim them ?
 
The CCI No. 34 at the bottom of the image below is a magnum primer used at Lake City for "ALL" 7.62 ammunition. And you can see from the lowest chamber pressure to the highest with the CCI No. 34 magnum primer is 2,600 psi. The manuals always tell you any time you change any reloading component to reduce the load 10% and work up again.

At the Hodgdon's website load data for the .308 with Varget and a 168 grain bullet the start load is 42 grains and max load is 46 grains Federal 210M, Large Rifle Match. The load you stated is one grain over max at the Hodgdon website and the magnum primer can boost chamber 2,600 psi. The Hodgdons website also stated that the max load of 46 grains was a compressed load. So are you sure of the load data you posted, meaning did you actually get 47 grains of powder in your cases.

The max load in the Hornady manual is 44 grains of Varget with a 168 grain bullet. I would unload the cases and look at several sources of load data and average the start load and work up again.

cmnvXVR.jpg


Below load data from https://rifleshooter.com/ And his max load is 45.5 grains of Varget.

dp7LkB3.png


Below the various case capacities of .308 cases that can affect chamber pressure.

Qvc8vVV.png
 
NOTE, the Gordons Reloading Tool simulation software shows the chamber over maximum and over 73,000 psi for your load.
This data below is without modifying Gordons default settings, and only 46 grains of Varget at 67,995 psi, and 47 grains would be over 73,000 psi.
(Captured picture at only 46 grains)
jAzA9Hs.png
 
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How did you arrive at 47 gr? My rifle maxes out at 46gr with a 155 gr bullet.

If 47 has been a good load in the past, the hotter primer won't make much difference.

The projected pressure over70,000 psi is approaching proof pressures. A well made rifle won't react to that, although the primer might look flat.

That is not a suggestion that you should plan on loading at 70K plus pressures.

I stand by my comment that the primer won't make much difference, but it appears that the load might be too hot to start with, unless you worked up to it.
 
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