Trying 300mp with 41AE. No data anywhere so I am starting with 357 mag data. For a 158g bullet it calls for 17g of powder. I will try my 170g Lehigh or my 170g Sierra but 17g wouldn't fit in the case anyway but I would of course start lower and I think I could get 14g plus the bullet in the case. Anyone see anything wrong with this thinking? Maybe start lower? Any input would be nice I have no other powders to try.  Craig

I don't think you can get enough of a powder that slow in a 41 AE case to cause concern. 

OTOH, I think you won't have any useful results either.  Maybe see if you can trade the powder for something faster and more cartridge appropriate.

Hey SQL thanks for the input. The 357 and the 41AE have the same SAMMI speck of 35.000 psi.
the 357 load for a 170g bullet is 17.5 max. I will start at  13 and work up fast but I can't get 17 in a case with bullet. I think it might take 16. but will work up of coarse.

41 AE is basically a very slightly larger 40 S&W.  5% larger radius, 5% larger case capacity, 5% larger surface area, same pressure.

Therefore, I would have no concerns using 40S&W data for 41 AE.  But there is not any 300 MP data for 40 S&W either.

Yeah same thing I ran into. I am not sure if you remember or not but I worked up a load with power pistol that works great except you can't buy it anywhere. I just finished 2 rounds of 13g 2 of 13.5 and 2  for 14g to test tomorrow. I measured 15g and it will fit but barely. I just would like to use this powder to get rid of it. Thanks again for the input.  Craig

OK shot the 13.0g this morning and it was perfect. Shot the 13.5 and got a jam and big fireballs when they did work. I didn't even bother with the 14g. The 13g round were so nice I will load a bunch of those. Thanks again SQL for you input!!!  Craig

BTW it is so nice to have a round work out these days with you not being able to buy the right stuff when you need it. For me this is a real sense of accomplishment. I am excited about loading more of the same thing.  Craig