Great ring but they don't work on everything - Area 419 Match Scope Rings

I bought 2 sets of these. The first set was for a 6GT build and they worked amazing. I really like the pin guided clamps and the low profile clamp to the base. However, the second set I bought was for a my defiance action with a integral rail and when they arrived I found the rings would not clamp tight to the rail. I reached out to customer service and didn't really get much in response other than "do you have the clamp the right orientation?" I did. I ended up returning and replacing with Nightforce rings and they clamped right down on the same rail. I am not saying not to buy or that I wouldn't buy them again, but be forewarned they may not fit every rail.