Is there any BDC type scope that has a constant hold over reticle regardless of zoom setting?

I bought a Nikon monarch, just happens to have a BDC reticle. If I wanted to tape logarithm tables to the stock I guess it's a good scope.

Any scope with a First Focal Plane (FFP) reticle would give you constant and, hopefully, shorter-distance rings or stadia. They are mostly the dearer European models but some American scopes may have it or give the option.

I've got a Nikon Monarch 4-16 with BDC but it only makes real sense if you wind it up to 16x. (I guess you've downloaded the Nikon dope.)

With a flat shooter like the 270WSM you can have it point blank out to 300 yards or, if worried about overshooting on steep shots, you could set it up for a 100 yard zero and use BDC as low as 6x.

My home-made inclinometer includes a table for 6x with a 95-yard zero, where the top of the first ring is for 366 yards and the middle 394 yards.

The middle of the second ring is 635 yards but I would forget about anything that far or farther, and you might want to watch shots at 250-300 yards as the near zero would see them drop a bit.

Another table with a 200 yard zero (I think) shows the middle of the first circle as 447 yards at 6x, so the top of the circle would probably be on about 400. The reason I mention 6x is because you can forget BDC at 4x and I hate to walk around with the power too high in case something jumps up right in front.

There are probably others, but these are a few that I am familiar with that fit your description.

Burris Veracity line of scopes, as well as their XTR 2. All first focal plane, the Veracity have a BDC reticle available, the XTR have MRAD reticles.

Nightforce with the Velocity reticles.

Vortex Viper HS LR with first focal plane and XLR reticle. Not a BDC reticle, but a MOA or MRAD reticle that you can work out your ballistics with.

Jeremy

Nikon has an app for calculating the holds at different magnifications and ammo loads. That can also be done on their website.

But otherwise you need a first focal plane scope.

LWD

With the reticle in the first focal plane the holdover reference marks will not change relative spacing as power is changed. However, if you crank the scope up to maximum power for a longer shot, the magnified reticle can sometimes be so large as to obscure the target. Almost EVERYTHING is a compromise when it comes to optics.