Yes, it will usually work, the only way to know for sure is to try it.
I don't know what happened to your quote, but yes, it's very likely you will get enough tension to hold the bullet in place.
It's pretty simple to size one and insert a projectile, then try to push the bullet into the case.
I've used .323 JS dies to reload for a .318 bore Westley Richards rifle I used to own.
I've also used .323 bullets for that rifle when I couldn't find .318 diameter bullets.
You need to be careful with some manuals, as they list loads meant for the JS bullets only. Usually, it's mentioned in the preamble, but not always.
In the later Lyman manuals, they mention their loads are for JS only.
Many of the older manuals show loads that only develop 38,000 psi, and North American commercial cartridge manufacturers loaded to that level in deference to the ammunition being loaded into rifles with smaller bores.
It's not something I would suggest anyone do. I was good with my rifle because it was strong enough to handle the lighter pressure loads.
Europeans are expected to know which designation is correct for their rifles, and issues from loading the wrong diameter are not the liability concern for the ammunition manufacturers as they are in North America, as long as the packaging and cartridge are appropriately marked.
The data in reloading manuals should be OK for the cartridges the OP is reloading, as long as the proper bullet diameters are used.
