Pre-primed brass- Questions

[3RDGEARGRNDRR]

We have all seen primered brass for sale, but my question would be
how do you know which primer is in them to start up the load data?

do you just assume that they would be magnum or non magnum primers?

300 X-out uses magnum powder but are these magnum primers?

Anybody have issues with primed brass?

['ol shooter]

Ask the seller, and use your best judgement.

[Full Clip]

Start at minimum, work your way up.

[tiller]

I would say it would use a 7 1/2 primer just based of the round and type of powder it uses