Unless your 7.9 gallon bucket is only about six inches high, the answer is no.
You'll have to either pick up the keggle to a higher level to drain it, or use a pump, or get the leg extensions, or build a stand for the Blichmann that is fireproof/fire resistant which will allow you to drain it into your bucket.
If I were to do that, I'd probably make a narrow stand out of 2x4s with a flat surface, use foil-faced insulation on top if it or maybe ceramic tiles, set the blichmann on top, and go. And I'd makes sure that the result was no warmer than warm to the touch.
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I went through this with the Hellfire--do I buy the extensions or do I not? They ended up costing about $63 with shipping, and against that price I had to weigh the cost of materials to build a stand and the time and effort involved to do that.
I figured it would be about $15 in materials, two trips to the home store (one to get what I needed, the second to get what I forgot), and about 2 hours additional time.
One also has to include the additional satisfaction of building something oneself and enjoying that result. Might be worth a lot of money depending.
Of course, if one doesn't have the $63 handy, it makes building more attractive, but in the end, I decided to go w/ the engineered extensions. I'm not in the least unhappy I did that.