Maxandy - First of all, welcome to the forum. Secondly, not all wheelsets are equal. Kadee for example are 1.015" tip to tip, a bit wider than many others. Intermountain are 1.005", Atlas are .930 or 1.015", and the original P2K are 1.010". The current Proto line which is now owned by Walther's is not the same as the P2K, the axle length is 1.015". Athearns are all over the place depending the freight car parentage of their models, Roundhouse, Details West etc. I have not bought any Athearns specifically, just measured what came in some of their RTR freight cars. After buying Athearn, Horizon Hobbies bought a few other kit manufacturers and now market everything as Athearn RTR.
The truck tuner that several have recommended is a must for any serious modeler. It isn't really meant to gouge out sideframes, but to merely smooth out and remove flash from what is already there. I have never used Jaybee's but they are smaller at .970". Best bet is to measure what came out and match as closely as possible. Undersized is better than oversize. In reality, the sideframe journal only rides on a small portion of the pointed axle end.
Other lengths may be available from the manufacturers that I have listed. There are also other manufacturers that I haven't used like Bowser, Rapido, Reboxx and Northwest.