On 10 October 2013, 22:01:17 UTC, PrimeGrid’s The Riesel Problem project eliminated k=304207 by finding the mega prime:
The prime is 1,999,918 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 11th elimination. 53 k's now remain.
The discovery was made by Randy Ready (cncr04s) of the United States using an Intel(R) Xeon(R) CPU X5570 @ 2.93GHz with 24 GB RAM running Windows Server 2003. This computer took 37 hours 36 minutes to complete the primality test using LLR. Randy is a member of the Aggie the Pew team.
For more details, please see the official announcement.