That's the reamer I used because that's the one I was told to use by folks here.
Before I reamed it though I slugged the bore and it came out .380. I loaded a dummey round with a .381 bullet and confirmed it would not chamber.
The original owner told me he had no problem chambering cartridges he loaded using a thinner brand of brass and .379 bullets. Based on the targets he sent me, they shot very well.
I now shoot .379 jacketed bullets and, had I done so from the beginning, may have not have had to ream the chamber. But the rifle shoots so good I'm not worried about it!
P.S. That's it in the avitar