Case prep for for reloading in a turret press?

[Army GI]

So I'm reading all I can from reloading manuals and watching the informational videos. One thing I noticed was that the reloading manuals (using a single stage press) re-size their brass first THEN trim to length, while the turret press guys trim to length first and THEN re-size.

The manual says that you must trim to length after you re-size because the neck stretches during the process.

Which is the correct answer? Because if the manual is right, that means all turret press users are loading brass with improper length unless they skip that stage in their press and do it separately.

[6079Winston]

I'm sure there are exceptions to the rule, but you should size, check case length and then trim and chamfer as necessary. I trim rilfe brass when it exceeds the maximum length and almost never trim pistol brass because it rarely seems to need it.

[Jicko]

Size then trim.

Otherwise, when it stretches as you size.... then your trim(case length) is no longer consistant/accurate.

[scewper]

Just measure how much your cases grow after sizing, then subtract this from your desired OAL. Trim to the new length. Your cases will "grow" to the correct length... I think.

I just use a single stage for now, but this seems most logical to me.

[What Just Happened?]

I would size then trim. If you do it the other way around, you won't get the actual length that you want but something longer.

The reason for the difference is probably because the turret guy is lazy. He doesn't want to interrupt the turret process.

[Timberwolf]

Size then trim as sizing stretches the brass - sizing after you trim defeats the purpose which is actually twofold - the main thing being uniformity.