Gun Control & RKBA

Guns and ammo in the hands of civilians is a bad thing.

linuxman: The Germans found that out in Warsaw.

Relatively hardly, unless you mean to be taken literally not facetiously. The 1943 uprising didn't cause nazis but about 20 deaths, while the ghetto was pretty much annihilated. Most of the nazis involved were not first rate soldiers, but older vets who were not deemed acceptable for front line duty.
The 1944 uprising was by the polish home army, albeit in good part civilians involved, and had this result:

Although the exact number of casualties remains unknown, it is estimated that about 16,000 members of the Polish resistance were killed and about 6,000 badly wounded. In addition, between 150,000 and 200,000 Polish civilians died, mostly from mass executions. {REPRISALS}
Jews being harboured by Poles were exposed by German house-to-house clearances and mass evictions of entire neighbourhoods. German casualties totalled over 8,000 soldiers killed and missing, and 9,000 wounded.
During the urban combat approximately 25% of Warsaw's buildings were destroyed. Following the surrender of Polish forces, German troops systematically levelled another 35% of the city block by block. Together with earlier damage suffered in the 1939 invasion of Poland and the Warsaw Ghetto Uprising in 1943, over 85% of the city was destroyed by January 1945, when the course of the events in the Eastern Front forced the Germans to abandon the city.

ghetto uprising 1943: 13,000 Jews died, about half of them burnt alive or suffocated. German casualties are not known, but were not more than 300. It was the largest single revolt by Jews during World War II.
Stroop's report, German forces suffered a total of 110 casualties – 17 dead (of whom 16 were killed in action) and 93 injured –

PS: Hitler actually made it easier for german civilians to possess firearms in waffengesetz ~1938;