Yes, I do believe it's legal in H/J. I looked it up online to confirm and found this:
If you download the USEA rulebook it'll tell you all the bit rules. It's not that hard, honest (I hate reading long regs too!) -- it's got the pages listed in the table of contents and you can scroll down right too it, I think it's even got pictures. |
USEF DOES allow the Boucher to be used in dressage-- so it should be fine for H/J as the dressage phase usually has the strictest bit requirements. It is very similar to a hanging cheek snaffle, which is allowed for all phases. I don't think copper rollers are allowed, or wire wrapped ones, but copper inlays are allowed as long as the mouthpieces are solid (single or double jointed are both legal).