Guys this might be a stupid question but I have to ask, a friend told me with a shorter barrel center fire rifle that you should use a faster burning powder and with a longer barrel you should use a slower buring powder, is there any truth to this and
if so is there any way I can determine the burn rate other that looking at the ballistic tables in my reloading manual?
Thx for all the advice.
Doug Olwin

There can be some truth to that. A lot of it has to do with caliber, cartridge, intended purpose and bullet weight. A .270 Winchester seems to like 4831, a slow burning powder and benefits from it more from a longer barrel. But if you have a shorter barrel you can get nearly as high of fps with Varget or 4064. A 7mm mag is similar from what I hear.

Load the cartridge not the barrel. That is why you should try several different bullet/powder combinations.