Have never heard of an underwater assault rifle. In the US, you must be 18 to buy a rifle, and 21 to buy a fully automatic rifle.
You will need to define assault rifle, and where you live. A TRUE assault rifle is a machine gun, and transfers of them are tightly regulated by the Federal government. What most people CALL an assault rifle is nothing but a semi-automatic rifle, and in most of the US, does not require a license to possess.
An assault rifle is defined by the US State Dept and Dept of Defense as a "lightweight, select-fire rifle firing light to intermediate power rounds". The term "select-fire" means the rifle can fire EITHER semi-automatic or full automatic by the use of a selector (usually a switch). Since a TRUE assault rifle can fire full-auto, they are heavily regualted by the 1934 National Fireamrs Act. The Plinker Plus AR-15 is NOT an assault rifle, so the answer to your question is NO. If, however, you are looking for a basic entry level model semi-automatic rifle that bears a resemblence to the M16, you could do worse.
Very basic difference is that an assault rifle is capable of both semi-automatic and full automatic fire with pull of the trigger. A rifle only fires once each time the trigger is pulled.The ammunition is important too. Assault rifles use a less-powerful ammo than rifles, but with less range. The result is that more ammo can be carried because of the reduced weight. For sniping at long ranges, the rifle is but the assault rifle has replaced it for short and intermediate ranges. In reality, assault rifle is a misnomer as it connects an action with a weapon. Any assault involving a rifle by definition means one is using an assault rifle. The M-1 Garrand rifle was a semi-automatic rifle used by American infantry throuought World War II for example. They certainly made assaults with this rifle. The same is true for the British Lee-Enfield 303 and Mauser bolt action rifles of the Commonwealth and German armies, respectively.One needs to understand that the term assault rifle has different meanings depending on the context, particularly in the US. The term "assault rifle" likely originated with the German Army which fielded a fully automatic rifle in World War II named the Sturmgewehr. Translated, this means literally "storm gun" or "storm rifle"; storm here being used as in storming the enemy. However, no other army has ever used the term "assault rifle" to describe weapons used by soldiers. The US Army and Marine Corps for example have always referred to rifles, including the fully-automatic M-16 and M4, as simply "rifles" or "weapons".Size of bullet doesn't define "assault rifle" either. The M-16 and M4 indeed fire a relatively small bullet, the 5.56 mmX45mm NATO round which weighs just 62 grains, although the cartridge is fairly large. On the other hand, the most widely produced fully automatic rifle in the world, the Kalashnikov AK-47, fires a bullet weighing 123 grains.Really, "assault rifle" is a term used principally in the US and outside the military to define just about any type of rifle that is semi- or fully-automatic. Those new to the US should understand that the term is generally used by the media and anti-gun advocates. And, again, beyond this there is no weapon or ballistically defined "assault rifle."Short Answer: a rifle fires a full-length long-range cartridge as a single shot or semiautomatic weapon. An assault rifle fires a less powerful close-range cartridge, and has full-automatic capability.
As a private citizen in the US- you can't. The TAVOR was introduced AFTER the ban on registration of new fully automatic weapons in the US (May 1986).
Colt and FN
I like the stainless steel Ruger mini 14. You did not say what cal. or rifle or pistol.
It is legal for a private citizen to own a fully automatic rifle in MOST US states IF you comply with Federal law (National Firearms Act- requires registration of full autos with the BATFE). Rather than list all the states that DO, why not post the state or states you are asking about?
Th XM8 rifle was developed by the US Army from the late 1990s to the early 2000s. It is a lightweight assault rifle. The US Army collaborated with Heckler & Koch to design the XM8 rifle.
1. WWII, first war in history in which every US fighting man was armed with a semi-automatic rifle, the M1 Garand. WWII created the AIRBORNE divisions (paratroopers). 2. Vietnam, first war in history in which every US fighting man was armed with a fully-automatic rifle, the M16 Jungle Rifle (assault rifle). Vietnam War created the AIRMOBILE divisions (helicopters). Note: Secretary of Defense McNamara "clarified the M16" for jungle warfare only.
Depends on what you mean by automatic guns, and the law where you live. You did not tell us where that is, so there is no way we can answer. Where I live you CAN legally own fully automatic firearms (machine guns) but they are horribly expensive. An M16 rifle that may be owned by a private citizen is between $12,000 and $16,000.
You need to tell us which rifle. Chances are that there is some legal way to own it.