Okay, I am thoroughly confused.

My speer manual lists load data for .30-06 150 gr. FMJ BT using IMR 4895 as minimum load of 45.5 gr. and a maximum load of 49.5 gr.

Hodgdon's (who owns IMR) reloading data website notes that for the same type of bullet, the same type of powder minimum load of 49 gr. and maximum of 53 gr.

What gives??? I am fairly new to reloading... does this sort of thing happen often between loading manuals?