300 WIN MAG Small Base Die Question

[TORCHRIDER]

I have a set of RCBS Small base 300 Win Mag dies. The small base die will not prevent me from just bumping the shoulder back 2 thousandths will it?

 

[Lefty7mmstw]

The only difference between small base and regular fl dies is that sb dies will take the brass down to normal factory dimensions, while regular fl dies usually are a bit on the large side...
That said, I wouldn't use a die in a manner that doesn't fully close the die; it invites canted brass and possible run out. I've seen first hand with one of my 7stw barrels where this makes a world of difference. I'm talking about 1 inch 200 yard groups turning into 3 inch groups by partial fl sizing. same day, same load, two die settings....

 

[TORCHRIDER]

The only difference between small base and regular fl dies is that sb dies will take the brass down to normal factory dimensions, while regular fl dies usually are a bit on the large side...
That said, I wouldn't use a die in a manner that doesn't fully close the die; it invites canted brass and possible run out. I've seen first hand with one of my 7stw barrels where this makes a world of difference. I'm talking about 1 inch 200 yard groups turning into 3 inch groups by partial fl sizing. same day, same load, two die settings....

Thank You but I am a little confused. Most people tell me to just run the die in far enough to bump the should back a thousandth or two on brass already fired in my rifle. If I run that die all the way down every time I size a case aren't I overworking the brass and shortening its life considerably? Should I get a different die than the small base die for reloading the 300 WM?

 

[alaska]

I only used the RCBS Small Base Sizer Die in the Browning BAR. When the SB dies were introduced by RCBS they even said on the box For Browning BAR.

 

[bigedp51]

TORCHRIDER

Yes you can use a small base die to bump the case shoulder back .001 or .002.

The problem with a small base die is it reduces the case diameter on average .001 smaller in diameter than a standard full length die and this may shorten case life.

We live in a plus and minus manufacturing world and chambers and dies vary in diameter and headspace length.

Example I have a "standard" Lee .223 full length sizing die that sizes the cases far smaller in diameter the any small base die I have. And my RCBS .223 small base die only makes the case .0005 smaller in diameter than my standard RCBS .223 full length die.

NOTE: The biggest problem with belted cases is a bulge just above the belt that is not reduced by the die and causes hard chambering. In this case when this happens I would buy the Belted Magnum collet resizing die from Larry Willis.

Innovative Technologies - Reloading Equipment

 

[TORCHRIDER]

TORCHRIDER

Yes you can use a small base die to bump the case shoulder back .001 or .002.

The problem with a small base die is it reduces the case diameter on average .001 smaller in diameter than a standard full length die and this may shorten case life.

We live in a plus and minus manufacturing world and chambers and dies vary in diameter and headspace length.

Example I have a "standard" Lee .223 full length sizing die that sizes the cases far smaller in diameter the any small base die I have. And my RCBS .223 small base die only makes the case .0005 smaller in diameter than my standard RCBS .223 full length die.

NOTE: The biggest problem with belted cases is a bulge just above the belt that is not reduced by the die and causes hard chambering. In this case when this happens I would buy the Belted Magnum collet resizing die from Larry Willis.

Innovative Technologies - Reloading Equipment

Thank You. I have already purchased the Willis collet die after reading a bunch on it. So it sounds like there will be little issue using my small base die to just bump the shoulder.

 

[Lefty7mmstw]

Thank You but I am a little confused. Most people tell me to just run the die in far enough to bump the should back a thousandth or two on brass already fired in my rifle. If I run that die all the way down every time I size a case aren't I overworking the brass and shortening its life considerably? Should I get a different die than the small base die for reloading the 300 WM?

In short, yes you should get a shoulder bump die.... fl and small base dies aren't designed to just bump the shoulder back a bit. It will work fine most times, but you can and sometimes do leave some accuracy on the table because you aren't keeping the brass straight. A better way (if you want to properly bump your brass with fl/sb dies)is to get a set of competition shellholders so you can match how much insertion into the die you need while still closing the die.
Another option is to get your rifle headspaced properly so you can use your existing equipment. I finally did that with my 7stw barrel as it was retiring the brass at three firings when set up for accuracy. It would have worked fine but someone had gun-plumbed the rifle and didn't check the receiver thread dimensions before ordering the barrel. Thirty thou. loose is way to loose in the rifle game. Needless to say I had a new match grade barrel in 7mmstw fitted properly to the receiver...