Went down stairs and photoed some rifles.
This is a Kibler 54 as it came.
This is my 50 cal swivel GM barrels used a lot hunting and matches.
This is a 50 cal McLemore barrel I use a .500 ball and either a heavy ticking or a .012-.014 linen.
This is a 50 cal GM.
This is a Don King Hawken with a Don King crown. Douglas. This barrel I freshed but shoots good with a .535 and heavy linen. Some former owner let it pit pretty heavily for about 12” up from the breech. Looking at the photo I wiped it out not rust.
This is a Don King Hawken 54 Douglas that I clumsily dinged the crown on some years back and had to recrown.
The basic idea is that the crown should not cut patches.
I can load any of these with just a rod, except the heavy match rifle with the bore sized ball. But this can put a lot of stress on the wrist. I loaded the one DK Hawken with just a rod for years and years. But I started using a starter with the swivel breech and since there is one with the pouches I use one most of the time. With larger bores, like my 16 bore rifle there is more material to compress a starter can make this easier.
So with any decent crown most rifles don’t need a starter for the typical ball/patch fit. But if you are shooting something really slim in the wrist or really tight ball fits it might be a good idea.