I’ve got 100 pieces of 1-2 fired Norma 270wsm brass.
Got rid of the 270 wsm , and brass is hard to sell. Anyone ever converted 270 wsm to 300 wsm ?

Not specifically those two but plenty of 270 to 30 calibre and 7mm to 30.

An expander plug for your dies will do it with ease. Just make sure you first run a bristle brush through the necks of the 270s. Basically, the sharper and hence flatter shoulder wont support the same force as for example a 270 Winchester case.

You will get a small donut at the junction of the neck and shoulder of the necked up cases. This occurs because when you neck up the 270 the very top of its shoulder becomes the bottom of the neck when it goes to 30 calibres.

For the average rifle and average use this neck up is easy and problem free.

Using standard Rcbs 300wsm dies.
What kind and size plug do I need .
Long time reloader here ,but total rookie at reforming brass !

You get a tapered expander plug for the dies. Usually they are football shaped. Very common.

Some dies will allow you to use the normal expander plug that come with dies.

Necking up or down one calibre such as 270 to 30 or 30 to 338 or 338 to 375 etc. is very easy and very common and trouble free.

However, with sharp shoulder brass just run the bristle brush through the 270 necks as the cold hard fouling in the necks has lots of friction and the shoulder can collapse.

There is a market for good .270 WSM brass

How many times fired, I maybe interested if you still want to sell them. Cost?

Pm’s Sent

Ok went ahead and tried 10 pieces.
I lubed the inside of the neck along with the rest of the case with Imperial. Then ran them very slowly through the rcbs 300 wsm sizing die. Annealed the neck and shoulder afterwards. Head space checked with the Hornady lock and load head space gauge checked the same as new 300wsm brass. Case length is .008 shorter than trim length , but I think they will be ok.
So should I load a starting point load touching the lands to fire form these ?
Or consider them good to go ?

Always a good idea to fire form brass before load development.

quote:

Originally posted by Deere:
So should I load a starting point load touching the lands to fire form these ?
Or consider them good to go ?

They should be good to go. The shoulder has not changed and it sounds like you've already checked them against official 300WSM brass. Fire forming is usually more important if you're trying to change the case, like forming a shoulder in a different place.