IA Born Report post Posted October 27, 2016 Question for those of you more knowledgeable than I in the rings department. I recently decided to upgrade my daughter's scope now that she's more serious about hunting. I'm going to be getting her a 30mm tube scope (Vortex Viper if it matters), so I bought new Dual Dove Tail rings for it. I bought the 30mm medium rings, thinking the height would be similar to the 1" medium rings I've always used. I had everything cerakoted for her as part of her upgrade/"being a good kid" present and, as I was mounting the rings last night, I put the original 1" scope in there just to see how it would look with the blue titanium cerakote (it looked awesome, btw). That's when I noticed that the Leuopold 30mm medium DD rings are shorter than her old 1" DD rings. Both the objective and occular bells on the scope were touching the barrel and receiver, respectively. I thought maybe Leupold screwed up and packaged low rings in a medium package, but when I looked at a pair at Sportsman's during lunch, they are definitely shorter. I picked up the 30mm DD rings at Sportsman's took them home to test them before cerakoting them (I do learn sometimes) and the objective bell sits just high enough, but the magnification dial on the ocular barely scratches the top of the receiver. Why are 30mm and 1" DD rings so different in height? I'm a complete rookie with 30mm-tube scopes, so bare with me. Are the objectives and oculars on 30mm scopes that much smaller that you don't need the extra height? I'm not a rocket scientist, but a 50mm objective is a 50mm objective, no matter the main tube diameter. Is there a difference in the ocular bells of a 30mm vs 1" tube scope? What am I missing? Am I just going to have to get the 30mm Super High DD rings? Thanks! P.S. I'm about to post a killer deal on a set of blue titanium 30mm Leupold DD rings in the classifieds. Can't return them since they've been cerakoted! D'oh! Share this post Link to post Share on other sites
mattys281 Report post Posted October 28, 2016 The 1" dimension refers to the centerline of the scope tube, and the 30mm (1.181") tube is .181" larger diameter than a 1" so the ring base would have to be approximately .0905" shorter to accommodate a larger tube and still maintain the 1" dimension to centerline. As for the 50mm objective, it should also be larger where it joins the 30mm tube, but I would think it would still taper to pretty close to the same size where the lense is mounted if it is the same brand. If its a different brand, then all bets are off as it was designed by different engineering team with different design philosophies, tooling constraints, mating part considerations, etc. It could be vastly different even though the glass is the same size. Share this post Link to post Share on other sites
IA Born Report post Posted October 28, 2016 The 1" dimension refers to the centerline of the scope tube, and the 30mm (1.181") tube is .181" larger diameter than a 1" so the ring base would have to be approximately .0905" shorter to accommodate a larger tube and still maintain the 1" dimension to centerline. As for the 50mm objective, it should also be larger where it joins the 30mm tube, but I would think it would still taper to pretty close to the same size where the lense is mounted if it is the same brand. If its a different brand, then all bets are off as it was designed by different engineering team with different design philosophies, tooling constraints, mating part considerations, etc. It could be vastly different even though the glass is the same size. Thanks, Mattys! I'm obviously ignorant to 30mm scopes since I've been using 1" scopes my whole life. I think the take away message from your post is to quit using the old 1" scope to try and figure out clearance on 30mm rings! I ordered her new scope this morning. Old and new are Vortex, so I'm hoping there will be consistency across engineering! I'll be using the scope to get the shortest rings I can possibly get for the very reason you mention! This will be my learning curve so I can get it figured out better for the next 30mm scope! Share this post Link to post Share on other sites
mattys281 Report post Posted October 28, 2016 No problem bud. Im not much of a rifle guy and certainly no scope expert, but I know manufacturing and interchangeable parts. Share this post Link to post Share on other sites
