Mig is the go to. Practice, Practice..... And Practice some more. You'll get it, go slow.
You can get a basic 120/240 V volt unit and use Flux Core wire for under 1K when on sale.
A good Grinder is a big help as well.
Is this them Skeets? https://en.wikipedia.org/wiki/Cluster_fly
I had them in my Camp, used Sevin sprayed on the ground around the outside to get rid of them.