The M14 served as the main service rifle for the US Military before it was replaced with the M16 which United States Army service in the jungle warfare operations of South Vietnam in 1963. It became adopted by other branches and became the U.S. military standard service rifle in 1969 which was the final phase out of the M14 as a main weapon.
Tokyo Marui kicked off the AEG market and it was their M16 that took the world by storm. Ever since, all other AEGs are compared to the core of Airsof that is made up of ARs. G&P got their start and to this day continues to build their line up of AR AEGs. Making a vast array of models, their high quality and performance as much as their modifiability makes them the benchmark standard in AEGs.
By mixing these two elements together, the G&P M16A1 is the model that saw action during the Vietnam war (although this one with the newer flash hider and not the three prong). The integrated carry handle, triangular foreguard and otherwise vanilla furniture (standard grip, fixed stock, sights, etc) come together to manifest an AEG in a specific era of time.
The low cost, high quality, good performance and near infinite future possibilities for modification make this weapon a fantastic choice for building a Vietnam era GI outfit around. At 380-400 FPS it is a solid skirmisher and the rear wired battery space in the fixed stock is massive enough to accommodate anything. With a decent cyclical rate turning on a 9.6v battery, this weapon is a good weapon for gaming as is.
With G&P design, the internals are already great but the modification potential boggles the mind. You can play with the motor and battery setup to crank out the rate of fire to ridiculous speeds, you can overhaul the spring and gears to pull a mightier spring; you may even consider adding period appropriate accessories like a sling, the older fixed magnification sights or a bayonet. At under 300 USD this is a great AEG by any standard and its long applications are as varied as your willingness to push the envelope.
This AEG has a rear wired small Tamiya type connector and the barrel uses the G&P standard 14mm clockwise threading.