you can get way more insurance with an umbrella that's why.
$600 for 1 million and 100k in criminal def.
1st 1 million is not near enough, you really need 2-5 min. ( lots of high profile scum bag lawyers out there)
the criminal side is not needed and its no where near enough. you can blow thru 100k in less then a month( don't ask me how I know) if you are really looking for a legal defense insurance there are better policys out that offer more for a fraction of the cost.
I have not read the policy, but one thing I would look at is if you have a stray bullet that hits some one . I would also look at rather or not it will defend you if you are in a gun free zone. in other words if you commited a criminal act willfully you lose all coverage. box of ammo says its there.
My 5 mill per incident 10 mil total umbrella is 1100 a year and it already covers the use of firearms in defense and even NDs. so for a little more then double I get 10x the coverage and it covers me for a whole bunch of other things.