Recently I came across a statement regarding the 300 WSM in a custom built long range rifle. Specifically:

quote:

a 300 WSM tightneck shooting the 125 Grain B. Tip in a 15 twist at 4043 FPS.

I'm wonder if this is not significantly higher performance than possible with a .300 Win Mag?

Also, I don't understand the term "tight neck"?

It is significantly higher, 300 - 400 fps ,than what is usually possible in either the 300 Win Mag or the 300 WSM

I'd say it was possible out of a custom rifle, its probably a hot load for that tough action and itd probably blow and standards rifle action to peices.

and wsms do beat the larger win mag with lighter projectiles but when they start getting heavier the win mag pulls out in front

Tightneck means the outside of the neck has to be thinned by turning down to fit the tight chamber. tight chambers allow a shooter to more or less custom tailor his brass to his gun. a turned neck and a tight chamber usually means better accuracy due to closer tolerances

and i'd say that velocity is either inflated or someone is living in the danger zone

they were probably flattening primers and getting a bit of primer flow... 4034fps is pretty fast..maybe too fast for realism. hmmm

Why would anyone want to shoot a 125 gr out of a 300 mag ?

I have a 300win mag and I can't get more than 3100fps with a 180nosler btbt. 4000+ is like a titan missile to me! 125's are for 308's what are they shooting at anyway. Dave

I loaded up some 125 BT's in my .300 Win mag this year for groundhog. They worked awesome!