I found that if solo it's easier to just stay invisible as their AI can't deal with that, and they either just stand there and take it (assuming no infested are around), or they come to you (they know perfectly where you are , they just fake not seeing you. Very badly, I might add), and hug you, so you can just blast their arms off.
If you put mallet down they start attacking it, while spazzing all over the place, making it much harder to hit their weakpoints.
Of course, since they only fake not knowing where you are, you can't get at their backs while solo without tossing a mallet d