Nikko Stirling gold crown help needed!

[Crouchy]

I recently purchase a nikko 4-12x 40mm gold crown from a fellow CGN on the EE. It went on a cheap old 22lr I inherited. It has the 30/30 ret (range estimating?) Now the question is there is what I assume to be yardages on the magnification ring. At each mag there is 3 letters D E A and a yardage (3 diget number) next to each. Anyone with any info on what the DEA stands for, and how to use the reticle for ranging? It did not come with the manual and google is not coming up with anything of any value. Thanks ahead of time for anything you guys... Or gals can offer.

 

[neal]

The ranging only worked with a certain selection of cartridges at a certain velocity.

I have one at some sitting on a shelf that came on a used rifle I bought. The only thing I can suggest is putting up a 1/2" grid target and try and work out what the ranging is for your load.

 

[Crouchy]

Okay thanks I will give that a try.