Does cartridge taper and shoulder angle have any effect on bolt thrust. I was reading some of the posts on another board on not using the 338 lapua in the savage action do to its high bolt thrust. It was stated that the case head of the lapua is too large in dia. and thus created too much bolt thrust, and the smaller dia of the RUM case has less thrust. It went on to say it is all about case dia and pressure, and powder capacity and bullet weight have little to do with bolt thrust. This got me thinking. It seems to me that the more tapered the case is the more thrust it could create IE improved cartridges having less. My reasoning on this is the more tapered case would act more like a wedge as it expands . Or does the thrust come from the shoulder? I am not trying to build a lapua on a savage action. And I am not saying it should or should not be done (I have my own opinion on that). It just got me thinking, would a lapua improved have less or more thrust do to more powder and less taper? How much testing has actually been done on bolt thrust? Anyone have any input on this ?