The Second Amendment was intended for civilians to be allowed to own military style weapons. To help understand this, let's look at the third amendment.
The Third Amendment states: "No Soldier shall, in time of peace be quartered in any house, without the consent of the Owner, nor in time of war, but in a manner to be prescribed by law."
This amendment was made because Britain was being a tyrannical gov. and was putting troops into colonized American homes because it could. This amendment was meant to go against a tyrannical gov. In fact, all the amendments were based off of this amendment and therefore to limit guns goes against the second amendment because you are creating a tyrannical gov.
Also, the murder count has been falling steadily since 2006 especially firearm murders