I have a #9 too....
But the #10 had loads that were a LOT hotter than the ones in #9 so I threw away the #9 and started using that one.
PS Seriously, a few things have changed since #9. Back then they advocated filling a rifle cartridge airspace with dacron and now they say, "NO WAY". Some people say it will 'ring' your barrel and some say it never happens.
Back in 1975 I bought a Speer #9 reloading manual and never looked back. It answered all my questions.
But the #10 had loads that were a LOT hotter than the ones in #9 so I threw away the #9 and started using that one.
PS Seriously, a few things have changed since #9. Back then they advocated filling a rifle cartridge airspace with dacron and now they say, "NO WAY". Some people say it will 'ring' your barrel and some say it never happens.