Over size 1x fired Norma 300 WSM brass

[Laguna Freak]

I bought 120 once fired Norma 300 WSM brass from a well known member here a couple years ago. I've been saving it for my custom build long action and recently FL sized and loaded some to shoot this weekend. They would not chamber because the case diameter at the webbing is 0.557". My Lee FL sizing die is unable to resize down to the webbing but my Hornady Custom Grade sizes them back down to 0.556" which enables chambering. The bolt is slightly stiff to close and open but it works. My question is, if I use these cases for load development in this rifle, will the heat and pressure / expansion and contraction of firing cause them to be a better fit for subsequent loads or am I wasting my time and components? Anyone have experience with this issue?

 

[nwmnbowhunter]

I would get new brass. Once brass is oversized it is tough to get keep it from getting bigger

 

[M1A1ABRAMS]

I bought 120 once fired Norma 300 WSM brass from a well known member here a couple years ago. I've been saving it for my custom build long action and recently FL sized and loaded some to shoot this weekend. They would not chamber because the case diameter at the webbing is 0.557". My Lee FL sizing die is unable to resize down to the webbing but my Hornady Custom Grade sizes them back down to 0.556" which enables chambering. The bolt is slightly stiff to close and open but it works. My question is, if I use these cases for load development in this rifle, will the heat and pressure / expansion and contraction of firing cause them to be a better fit for subsequent loads or am I wasting my time and components? Anyone have experience with this issue?

Perhaps this die would be helpful ? You may need to call them about the caliber you need. https://www.larrywillis.com/300winmag.html

 

[nwmnbowhunter]

Bullet central micron die might do it but it isn't cheap

 

[Ross1147]

So I ran into this issue a few years ago. I had a Benelli R1 in 300WSM, saved all brass I shot in it. My first custom was a 300WSM on defiance deviant action and proof barrel. Not a single piece of brass fit after being full length resigned in RCBS dies. I was so confused, even went as far as calling Defiance and questioned them. This is when I found out brass can be oversized from a larger chamber. I posted on this site and found out about small base dies. Maybe those would work, but for me it was cheaper to just scrap all the brass use new.

With 120 Norma I'd try to pick up a small base die and see if it'd work? Norma is $$ brass.

 

[QuietTexan]

You could try an RCBS small base die for the 300 WM. Should size all the way down to the web

 

[QuietTexan]

I'd try to pick up a small base die and see if it'd work?

Beat me by a click!

 

[MagnumManiac]

An easy solution is to take .010" off the top of a shell holder…it may size the shoulder too much, so measuring the datum should be done before going further after altering a shell holder.

Cheers.

 

[Laguna Freak]

Thanks for all the good ideas! Before I spend any more $$, I sized 12 cases in my Hornady FL die and they all chamber with a slightly stiff closing of the bolt. I'm going to continue the next step of load development with them and see how they respond to firing. I'm hoping they'll contract from .556" back to 0.555". Then I can get the shoulders back to where they need to be.

Lesson learned; when buying once fired rifle brass, ask about head diameter at the web. Doh!

 

[comfisherman]

Like Ross1147 I had a 300wsm savage that had a chamber we affectionately called the "savage Ackley ". Nothing fired out of it chambered in anything else, and fl die sizing took lube and arm muscles and eventually neck sizing. Wouldn't chamber in other 300 wsm rifles.

Sounds like some good solutions pit forward. Downside of 2nd hand. Every now and again it has its pitfalls.

 

[Mikecr]

I'm hoping they'll contract from .556" back to 0.555".

That will never happen. Doesn't work that way

Whatever brass expands to, anywhere, it wants to go right back to, regardless of sizing.
You should not waste a minute with that brass. Buy new, form it correctly to YOUR chamber.

 

[shortgrass]

Just made a quick search, I can't seem to find .300WSM Small Base sizer dies. My search was not a complete one. Personally, I don't think they are made, except on a custom basis. Could be wrong, but small base sizers are usually only made for cartridges chambered for autoloaders. The Larry Willis die won't work, either,,,,, as it is made for belted magnums. Custom cut chambers deserve new brass. Brass from a factory chamber most likely isn't going to fit!

 

[nwmnbowhunter]

Unknown has new brass in stock

 

[Beluebow]

You're gonna be in clicker he** with that brass.

The closest thing to a small base without going custom is a Bullet Central Micron die....if you plan on owning and shooting a 300WSM I highly recommend it.

I agree with the other posters....get new brass.