but it is there. And a lot of American gun control activists who idealize Europe would be shocked and horrified that AR-15's and other modern-looking rifles are legal across much of Europe, including Germany.

80 million germans, approx. 7 million legal firearms, tack on 20 million illegal or illicit firearms. More like lax enforcement.

The estimated rate of private gun ownership (both licit and illicit) in Germany is 30.31 firearms per 100 people
The estimated total number of guns (both licit and illicit) held by civilians in Germany is 25,000,000

Unlawfully held guns .. in Germany there are estimated to be 17,000,000
Unlawfully held guns .. in Germany there are estimated to be 20.615 illicit firearms per 100 people

In a comparison of the number of privately owned guns in 178 countries, Germany ranked at No. 4
In a comparison of the rate of private gun ownership in 178 countries, Germany ranked at No. 15

Both are misleading, since ~70% of those firearms are illegal or illicit.

The number of licensed gun owners in Germany is reported to be 2,000,000 {of 80 million pop}
The rate of licensed firearm owners per 100 people in Germany is 2.445

(US ~10.6) Germany, annual rate of all gun deaths per 100,000 population is
2012: 1.015/ 2011: 1.08/ 2010: 1.1013/ 2009: 1.145/ 2008: 1.16/ 2007: 1.17

(US ~3.5) Germany, annual rate of firearm homicide per 100,000 population is
2012: 0.079 2011: 0.07 2010: 0.069 15 2009: 0.09 2008: 0.07 2007: 0.07

(US ~65%) Germany, percentage of homicides committed with a firearm is reported to be
2011: 13%16 2010: 26.3%15 2009: 29.9% 2008: 26.1% 2007: 26.9%
http://www.gunpolicy.org/firearms/region/germany

In Germany, private possession of semi-automatic assault weapons is permitted only with special authorisation
.. private possession of handguns (pistols and revolvers) is permitted only with special authorisa
.. civilian possession of rifles and shotguns is regulated by law
.. carrying a firearm in plain view in a public place is allowed, subject to a valid permit (in exceptional circumstances
.. the maximum penalty for unlawful possession of a firearm104 is 10 years in prison
.. state policy to destroy surplus, collected and seized firearms rather than return them to the secondary arms market
http://www.gunpolicy.org/firearms/region/germany