Picked up a Vulcan3 700 mm in .30 used. Rifle was purchased new in 11/2025 and looks new. I had a chance to shoot it today and the AVS .3063 flat base slugs in 61 gr were averaging 961 fps at about 124 fpe. They were a little tight to chamber in breech. Does that sound correct ? Also does anyone know where to purchase an adapter to install a 700cc carbon bottle on this rifle ?