Reloading different rifle casings

[Crunchy]

Ok, a question or two on reloading.  I recently picked up a pre 64 Win model 70 in .338.  With it I got 80 casings of once fired Winchester brass, and another 60 or so of Browing brass.  Can I reloading the different casings the same or should I ditch one for the other, or both and pick out something else? 

[JimmyHoffa]

There could be some slight differences in performance, but depending on how much consistency you need it might not even be a factor...then again.  Are you going to be happy with a 100 fps spread and/or 1 MOA or are you looking for 1/8 MOA?

[NWShooter]

Start off by full length sizing them all, as long as your loading to a manual you will be fine. If you choose to start working to a max load for your rifle. Each head stamp will be different from another when it comes to top end loads. Just work them up and watch for pressure signs. If it were me, I would choose one head stamp and run with it. Different case manufacturers have different case capacities due to case thickness.

May want to load a few of the same load in both cases and see which shoots tighter and go with those cases. You can always go with a different head stamp. No need if what you have will shoot well enough for you.

[300rum]

Unless you are trying to get to the bitter edge you will be fine.  How far do you plan on shooting, up to 400yds?  You probably won't be able to tell that much of a difference.       

[AWS]

Just weigh them, deprime them, size and trim so they are exactly alike on the outside.  If they weigh the same or very close that means they have the same amount of brass in them and should have almost the same capacity and shoot nearly the same.  Second prime them and fill them to the top with a fine ball powder tap them down and level with a knife.  Pour one into the pan of your scale and weigh the powder, do the same with the second one .  If the powder weighs the same they they should shoot pretty much the same.