Anyone do any improving on the 300wsm cartridge? I am thinking that it's 0.295" neck is a bit short for 210gr Bergers. Any leads or ideas?
Yes, I do have the "Custom Cartridges" book. Many thanks, Overbore

If the neck provides enough neck tension I see no reason to change it unless you are trying to get a particular bullet to fit in the case and also get close to the lands. In that case you might consider having the barrel set back and rechambered with a throat that suits your needs.
Often factory rifles have a lot of "leade" or distance from the end of the case to the beginning of the rifling. Weatherby does this all the time to control pressure peaks. Most folks think that the shorter the distance from the bullet to the rifling is the best. You'll have to decide.

You could form a SAUM case from a WSM case. The result would be a longer neck and a tighter fit in the chamber. The down side is that the form dies would be expensive.

If you keep the case the same length and lengthen the neck, all you'll do is reduce powder capacity.

Yes, the bullet won't protrude into the powder capacity as far, but since you have less to start with you will still be left with less. The shank of the bullet at a certain OAL takes up the same amount of powder capacity, be it in the neck or below the neck.

In other words, you will see no gain. Don't worry about it--shove them in there.

Gents, thanks for your response but I have not seen that anyone has tried it. Agreed,slightly faster ,4350, powder is required to compensate for the lack of powder room but PO Ackley thought 0.425" neck was right for the '06AI and he was known for doing the right thing.. Cordially, Overbore

GCA,

You said " 4350 ", H4350 is great in 300 WSM under 150 - 155 Gr. bullets !

Travis F.

Roger that. Travis, when you develop arthritis the coma was intended to be Bruce's powder -if you go back that far. Thanks,