Not sure if this post should be here or reloading. Hope it helps someone

My M70 Classic 300 Win Mag was not giving the accuracy I wanted (2" groups/100yds). I tried many different loads, bullets, etc. I checked the freebore with 3.340 OAL and the bullet was over 1/4" from the lands.

When I loaded to an OAL of 3.470, the groups went to 3/4".

I lengthened the magazine by removing the rear spacer. I have since replaced the magazine with a factory replacement from a 375. I filed the ejector to pick up the longer cartridge.

Good work. You have now changed the dynamics of the 300 WM the way it should have been done by WW.

JBoutfishn: Thanks for that information; it is interesting. Did you have to make any change to the bolt stop in order to accommodate the longer cartridges?

quote:

Originally posted by BigBrass:
JBoutfishn: Thanks for that information; it is interesting. Did you have to make any change to the bolt stop in order to accommodate the longer cartridges?

That was anticipated, but proved to be not necessary.

very interesting post !
I have 2 classics that realate to this story, 1 is a 7mmSTW witch I asume has the same magazine, as the one you put in your 300.
The other is a .338 Win. Let me point out a couple things. With my stw, I can't get to close to the lands either , but inspite of that, the rifle is more accurate than any one would belive. I have shot many 3 shot groups with 2 powders and 3 or 4 bullets that were well under a Quarter inch. My .338 is another story. While it does better than 2 inches it does not do a whole lot better.
I looked at it after reading this post and it has the same spacer. I am thinking of removing it, but mabye I will just try using the mag from the stw 1st.
The .338 if I were a more logical creature shoots around 1.5 inches witch is plenty accurate for Elk hunting but I so love to walk away from the range holding targets that have 1 large hole just above the Bull...tj3006