Will overfilling my 310cc saline implants make them harder?

Generally speaking, overfilled breast implants ripple less, are harder and over-project looking more fake. There's an acceptable limit to overfilling which your surgeon should be able to discuss with you. Too much overfill is not good either. If you're so worried about rippling, you should seek a superior product in silicone breast implants. Best wishes, Dr. ALDO 

It is about finding the happy medium.  Some diminishment of risk of rippling without the implant being too firm.

overfilling  a saline implant will reduce the risk for post operative rippling , but will make them more firm and will distort the shape of the implant to be rounder and more ball like rather than a disc. Overfilling also increases the risk for rupture later, particularly if you go significantly beyond the recommended fill volume.In the past, when saline was the only product on the market, many PS would overfill to try to reduce rippling. I would be interested to know why you are considering saline implants. The advantages of gel implants outweigh the saline,

Overfilling does make them firmer, but also prevents rippling to some degree.  There is also a saline implant called the Ideal Implant which is softer and has less rippling which is something that you may want to research if you are doing saline....  Good luck!

I think that you have a good understanding.  Overfilling saline breast implants can result in less rippling, but also results in a more firm feel.   Ultimately, much will depend on what type of aesthetic outcome you wish to achieve with breast augmentation surgery. My best advice: careful selection of plastic surgeon and careful communication of their goals. Learn about the pros/cons/risks/complications associated with all options. Working closely with your plastic surgeon you will come up with a good plan to achieve your desired outcome. Best wishes

Overfilling saline breast implants higher than the recommended inflation range will in fact cause rippling.  Modern saline implants are designed to be filled in a proper range which will prevent rippling.  Overfilling is something that used to be done in the 1990s which is no longer properly done as the current inflation range is designed to prevent rippling.

 Overfilling saline breast implants can result in less rippling, but also results in a more firm feel.  For a more natural look and feel consider the new gummy bear ( cohesive gel) implants.