Hi, folks. This may be, perhaps a dumb question, but I am a novice at most things shotgun. Background: Of all my firearms, there is but one shotgun - a Mossberg 930 with two interchangeable barrels. I bought it exclusively for home/farm defense (don't hunt) and got 250 rounds of 12g 00 Buck. Of late, I've been pondering "what if an Antifa crowd with torches and molotovs bypassed my No Trespassing signs and began marching toward either my home or my barn complex???". The gate to my property (technically my property extends beyond the gate a bit) is about 800' from our home and about 600' from our barn complex. I have long guns (5.56mm/.223 REM) with sufficient effective range to shoot at individual targets with deadly force. The downside (other than legalities) is the possibility of an over-shot or miss that could impact a neighbor's home 1800-2000' distant. What I am considering is using the Mossy (with its 16.5" barrel) with standard 00 Buck ammo. No choke. It would - in effect - be an "area weapon" at <=800'. I don't expect (or desire) tight shot grouping and would prefer mostly discouraging a group from staying or further advancing on my property. At an 800' range I suspect 00 Buck would not be particularly lethal but sufficiently dangerous and injurious enough to discourage sticking around. Also, misses/overshots would be very unlikely to cause damage or danger to my neighbor's house (or even reach it). Question: I know the shot spread would be very wide, but am at a loss as to how much drop at 800' I should correct for. Thanks in advance. I have ballistics tables and drop info for 5.56, .223, and .30 Carbine, but haven't found any info for shotguns firing 00 Buck.