If you open the .bot file you might be able to find it by searching (ctrl + f) for "Burst". For example in the image below, I found that my robot Reptilium uses pneuburst1.txt for its hammer. Note that skirt hinges are also counted as burst motors so keep that in mind while searching through the .bot file.
Also, when attaching images to your post, make sure you click the "Insert Attachment" link next to the file to actually put the image into your post.