300 win

M

Mike calkins

Inactive
on my mod 70 I seem to have excessive length to my chamber. when I made up a dummy round I found that the cartridge was about 1/4 " to long for my magazine. This seems to mean that my loaded shells are going to be a long way off the lands. I am not getting very good accuracy from this rifle. about 1" + groups with the cartridges loaded to fit the magazine. any suggestions on changes I can Make for improvement?
 
f you are getting 1 inch groups at 100 then you are plenty good for hunting. I hunted with a 7mm that was no better than 1.5 inches. Even 2 inches back then was not considered bad.

You want to target shoot a bit (300 wm is not my choice for that!) then you can make as long as needed and single load.

There are some lower loads for 300 WM that can take it down to 30-06 levels or a bit lower.
 
Every recent model 70 I have worked with, and I own a few, has a chamber on the long side of spec, a magazine on the short side, and too much freebore. HOWEVER, I have not seen one that will not shoot an inch or under at 100 yards with quality ammo or the right hand load.

In my opinion, your options are to re-barrel or have a good smith re-chamber, re-stock and lengthen the magazine, or hunt with a box stock rifle that's about as good as they come these days. I am not personally aware of any stock factory rifle that will consistently shoot 1/2" groups with virtually any ammo and by virtually any shooter. If I'm missing one, I would sincerely love to know about it. ;)

ETA: Just thought I would add that one of my Model 70's is an "Extreme Weather" in 300WM. The best load I have found for it so far is 82g of Magnum in a WW case, CCI primer, 180g Accubond and COAL OF 3.36 which is as long as I can go in the magazine.
 
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on my mod 70 I seem to have excessive length to my chamber. when I made up a dummy round I found that the cartridge was about 1/4 " to long for my magazine. This seems to mean that my loaded shells are going to be a long way off the lands.
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Scary! The scary part about that statement is the part where it makes sense to reloaders.

I your rifle has been throated the round with the long OAL will chamber but will not feed from the magazine meaning you will be able to load the rifle as a single shot.

And then there is the length of the chamber from the bolt face to the shoulder of the chamber. 1/4" is .250", I have tested chambers that were so long I could push the bullet out of the case and into the throat before the bullet contacted the rifling.

Remember, the neck of the 300 WM is short, it is close to being .268", I have build wildcats with case necks of .217"; if .268 is short, .217" is too short.

In the old days I was never impressed with individuals that chambered their 300 WMs in such a way that allowed them to move the bullet out of the case with more bullet hold by increasing the length of the throat and neck. I can not argue with the results, but my argument was about the life span of the owner. Used rifles do not come with a printed history.

There is a technique that would allow you to determine how long the chamber is from the end of the chamber neck to the bolt face, and then there are all of those reloaders that claim it can not be done.

For the extra case length/long neck the old guys use 300 Weatherb cases.

F. Guffey
 
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