R6300 resembles the WNDR4500 by Netgear, and the 2.4 GHz chip is the same (BCM4331). The CPU, the Broadcom BSM4706 clocked at 600 MHz, is a familiar face as well. The R6300 also has 128 MB NAND flash storage (Samsung K9F1G08U0D) and two Winbond modules with 64 MB DDR2 memory each. You could therefore say that the R6300 is a WNDR4500 with a different 5GHz module, although it looks like the former has a different switch than the latter. The R6300 has the Broadcom BCM53125, while the WNDR4500 has the BCM53115.
Keeping that in mind, you can flash a suitable .chk file. Please keep in mind that the 5Ghz might not be supported initially OR you might have some problems with it. Unless you are a hard core modder for routers then I suggest you wait for a while for shibby20 to come up with a formal announcement.
Have a great day!
I learn something new from everyone everyday. A hardware and software hacker .
My Routers: Buffalo WHR HP G54, WRT54G-TM, WRT54GL, ASUS RT N16, DLINK DIR600, Linksys E3200, Tplink 1043ND, ASUS RT N13B, Alfa R36