Remember that I mentioned SAAMI and CIP in a previous post? All ammunition amnufaturers follow either one or the other's specifications. Yes, I realize that there are some countries that probably don't follow them precisely. I can guarantee that Sellior and Belliot does, or they wouldn't be able to sell ammo worldwide. Keep in mind that what SAAMI publishes are voluntary guidelines and there is no Government body enforcing regulation of their recommended practices.Thank you Xl_Target sir completely agree with you the diameter of a bullet cannot change however the thickness of the jacket may vary with different makes of the same caliber,then again when the bullet is loaded in to the chamber and when the bolt is being closed one needs to apply a bit of effort ,so that is where i believe the rifling gets embedded in to the bullet
In this case the jacket thickness is of no importance. If a bullet has a thicker jacket, the diameter of the lead under it will be reduced. The overall diameter of the bullet, whether jacketed or should be the same.
In a commercial rifle with commercial ammunition, the rifle should not engrave the bullet when chambering. If the bullet touches the lands, there could be an increase in pressure which could be dangerous. There is usually a short "leade" or non-rifled area between the bullet and the rifling. If a cartridge requires extra force to close the bolt on it, you might be crushing the shoulder or have a chamber that is not exactly to SAAMI or CIP specifications. A 30-06 headspaces on the shoulder. How much effort do you mean when you say " a bit of effort"? It is hard to tell you what is normal till one feels it for oneself.
Keep in mind that we are talking NOT talking about handloading and custom chambers.