sansamour14 said:
Please also take into account that if your rifle were to become the next standard our soldiers
In some areas of the US military the M4 has already replaced the M16A4 as standard issues, which was a cost saving decision (and a bad one as M4's suffer faster wear from the shorter stroke piston).
The SCAR-L/H is already replacing the M4 and M21 as a special issue weapon, but it is too expensive for general issue.
The Marines are in the process of replacing their rifles with Heckler and Koch M27s, which is essentially based off the M16/M4 but with HK's own short stroke piston that is far more reliable than Colt's. It also doesn't have the tendency to explode in the event of a barrel obstruction like M16s can do. That was announced last year and is tentatively dated as being complete by 2014.
The XM8/29 OICW project has been cancelled entirely. The rifle istelf was a H&K G36 internally, but with a different plastic frame to differentiate it, the G36 is reliable, but itself is a design almost 20years old now and technology has moved on.
H&K have since made the 416/M27 line which has identical controls to the M16 but with the greater reliability and safety I mentioned above. It's probably going to be adopted as a replacement for M16s as it is fairly cheap, identical to use and an improvement in all other aspects.
As far as adopting a new type of ammunition, a new cartridge is unlikely to happen as Nato has agreed on standardised rounds, so forcing the adoption of something other than .223 or .308 is unlikely.