Quick back story.  About a week ago I bought a used Nano. It has a problem extracting empty cases, but only on 115 grain loads, it works fine with 124 and 147 grain loads.  I've come to learn that this is a common problem and Beretta polishes the chamber and puts upgraded parts in the guns returned to them for this issue.  

So I wrote to Beretta and asked if I could buy the upgraded parts and install them myself.  I informed them straight up that I purchased it used. I got the "We believe that it would be best if one of our factory-trained technicians diagnosed your firearm" email response with the offer to generate a free return label.

Should I send it back, or just not use 115 grain ammo (which unfortunately includes almost all the inexpensive range ammo)?  Will Beretta cover it under warranty or do they charge for repairing guns purchased used? Or should I try polishing the chamber myself?  I've done it before with Flitz and a cotton wad cleaner.

Never heard of this issue. Ive carried one for about 4-5 years and never had a jam or extraction issue at the range.

Lot's of discussion and videos available, do a search for "Beretta Nano 115 grain" and you'll find lots of examples.  

Apparently extraction happens a little to early with 115 grain loads, before the case has had a chance to shrink away from the chamber wall.  I had two different 115 grain, two 124 grain loads and one 147.  I had 8 to 10 stoppages in 50 rounds with the 115's and not one with any of the heavier loads.

Here's a pic of one of the failures on mine, they're all the same.  At this point the case isn't stuck, lock back the slide and the case drops freely.

My Nano was manufactured in 2013, so it's probably about the same age yours is.  

It has been a well documented issue with some of the early Nanos. You send it in and they replace the extractor and polish the feed ramp. This USUALLY solves the issue. But, there have been some Nanos that have to be sent in again.

I have one of the early ones, but I have not experienced it. However, I don't shoot under 124gr ammunition. I really like mine, but my wife stole it!!

I have read reports of some Nanos that start with problems with 115gr and after shooting 200 rounds, they smooth out and work fine.

Since the gun is out of warranty I think I'll polish the chamber and try a box of Fiocchi 124 grain ball and if it doesn't happen again just forget about it.  This isn't going to be a range toy, I'll probably fire a box of practice ammo and a mag of self defense ammo once every few months.

I can always buy another extractor from Brownell's if I need to.

I was impressed with how the gun functioned and handled with Gold Dot and HST 124 grain loads as well as the HST 147 grain +P load. 

I bought a new extractor and extractor spring from MWG. Did the polished the feed ramp myself. My Nano is a 2012 production model and had problems feeding and extracting. After the upgrade I haven't had any problems.

Nice!  I'm going to order an extractor and extractor spring.  I polished the chamber and feed ramp earlier this evening.  I've never had feed issues, just the failure to extract with 115 grain ammo.

I put the Pearce extension on my 6 round mag, the other came with the +2 extension.  I put the sticky grip tape on it too.  And mine came with CT Laser.

I was having double feeds and failures to extract. With my carry ammo the 147gr Fed HST +P it ran find I just didn't like the idea that I couldn't shoot range ammo through it. It was so bad I was clearing a malfunction every mag. After the fix I haven't had a problem.

Pretty much the boat I'm in.  I'm satisfied that it's reliable with self defense ammo, polishing the chamber and replacing the extractor and spring (and probably the plunger and rod since they're cheap) is just so I can run cheap 115 grain range ammo.  And if that doesn't work I'll either buy a few hundred rounds of the Fiocchi 124 grain or buy 124 grain bullets and load them myself.