Whenever I see the Russians using SAMs to take out these small drones, often commercial ones like you-know-who, I keep thinking wouldn't it be more economical to use ack-acks like a Zu-23 instead?
Granted it wouldn't be as precise, but the flak rounds would take them out just the same. Even with something as old as a Strela-10 or an Osa, I just think how cost-ineffective it is, that they'd be better served taking out helos or Su-25s (whatever the Ukrainians got left) and actual military drones like the TB2.
There is a general misconception thanks to Hollywood that all guns are precision sniper rifles. In reality, different guns have different accuracy levels, and anti-aircraft guns are not precise by design.
The general principle with small cal AA guns is that you throw rounds in a spread pattern tight enough to be aimed effectively, but loose enough that your rounds cover a much bigger area at the intended optimal engagement range to maximise your hit chance while still achieving enough hits to have a reasonable chance to bringing down aircraft.
The issue is the vast size discrepancy between dronesand manned aircraft.
A good analogy would be clay pigeon shooting.
You can be a world champion shooter and can hit 99.9% of clays, but your kill rate is still going to approximate zero if you were asked to shoot at flies with your shotgun at the same range as you normally shoot clays.
The other aspect that makes it worthwhile using missiles rather than taking pot shots with AA guns all day long is time.
Those drones are not there taking candid photos of your misses sunbathing. They are there acting as spotters for enemy forces. The more time you allow them over your position, the greater the chances of your position and troops getting hit by enemy long range weapons such as artillery or missiles or MRLS or your forward troops getting ambushed.
Sure, it’s not economical, but lives are worth a lot more and it’s a good deal to shoot at drones with SAMs if it can help save lives of your troops. Besides, with the Ukraine air forces effectively destroyed, its not like they need those SAMs for anything else right now do they?