I bought a Star BM for $200 at the LGS.  I finally got to the range with it and a few other things and it choked.  The gun would frequently fail to fully extract, the case being stuck half-way out the chamber.  OK, I didn't clean it at all, I had just grabbed it on the way out as an afterthought to try out with the Sig P6.  The P6 worked wonderfully BTW.  Anyway, I was shooting Win whitebox.  So I took it home and cleaned it up.  The chamber itself was kinda cruddy.  It cleaned up well, and along with the rest of the gun, I payed close attention to the extractor as well.  I took it back to the range today and shot PMC out of it.  It ran like a top, and was one of the most accurate 9mm's I've owned.  The 1911-style SA trigger was a tad on the heavy side, but very crisp and the sights are very nice on the gun and easy to see.  I mean I was impressed with the little gun.  

I've bought guns for alot more money that this BM that didn't shoot anywhere near as well.  It came with two factory mags, and I ran them both with no trouble whatsoever.  I really like this thing.

Insure that your firing pin is really inertial and use snap caps to dry fire.

Change the springs.  Ihave 3 of them. Great guns. I have two surplus Police models from 1976 and 1977. I recently  got one  LNIB  appeared unfired .JET71.