Imr3031 is what I use but for the 125 starting load is 41.5 and max is 46. 2.900 OAL..need to get you several manuals. The 174 start 37 max 41.5 and 3.075 OAL..always check to make sure you aren't in the lands and you should be ok in length if you don't have a cannulure. If old Enfield SMLE...
As long as you aren't Reallly pushing the limits no issue at all. I use the mags regularly in large rifle and small in 38..just what I have on hand at the time.
Ok think about it a bit..sure you are talking 1000ths. But you are tumbling powder..you are changing the powder extrusion by friction one way or the other..not to mention live primers bouncing off one another. Glad it works but don't think I will try it just me and the way I was taught.