They shouldn't have a problem with it, but I don't know how specific a "go ahead, that's legal" answer you will get. Most times they simply quote the pertinent regulation and then say it might or might not be legal depending on whatever. They like a lot of wiggle room when it comes to their legal interpretations. Can't hurt to try though.
There is also the very real personal liability issues you get into if something should ever happen involving the rifle.