New vs. Old

[ultratec1]

I have a question for everyone here. I have noticed that my loads shoot better with new virgin brass compared to once fired. What am I doing wrong? I full length resize and trim all brass to the recommended length. I have really noticed it in my .243. My New Winchester makes one hole groups and my R@P brass doesn't group as well.

Do I need to separate all brass according to brand and find a load development for each?? I hope this isn't the case.

 

[jwrowland77]

Yes you should separate all your headstamps to do a full workup for each if you're looking for accuracy. The reason is, is different brand case will have different case capacity. So you'll have different internal pressures.

It may be too that your rifle really like one type of brass compared to other types of brass. My rifle really seems to like Win and Lapua.

 

[witchhunter]

I usually pick the brand that I have the most of and use that for load workups. I trade brass with other shooters around here so it works out. That is the first thing that will start to make your rifle shoot better. You want to be consistent.

 

[ArchAngelCD]

I also keep brands of brass separate and load them in groups.

As for new brass shooting best, IMO it's because the neck tension is most similar when loading new brass which was annealed by the factory. Every time you shoot and resize the case you slightly work harder the case and none will be exactly the same again unless you anneal them yourself. Note, the change is very small and unless you are shooting Benchrest I would not worry about it, especially for hunting ammo...