anyone drill out a Russian 91%?

[nynvolt]

I purchased a generic "Russian style" rta, the merchant drilled it out to increase the airflow. I liked it so well I bought the real Russian. It's so much better quality wise but the draw even with the airflow screw out is a bit tighter than the clone.

I think I could carefully bore out the air hole plus increase the hole in the center post a tad but I don't want to destroy my $100 atty...

So anyone done this before with good results?

TIA.