Two LR 306 attys arrived today from AvidVaper. Neither will screw into my Silver Bullet. The SB is new but I don't think it is the problem. Other cartos and attys go on it fine. The 306s go about 3/4 the way in and screw no further. Husband got it off the SB for me with a cloth and pliers. Tried the 2nd one and the same thing happened. Bummer. Am I doing something wrong? Is there a trick? I'm afraid to try the 306s on my GLV2. If I broke my go-to mod That would be very bad. Thanks a bunch.