SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have some sprinkler heads in my back yard that I need to replace and on the top they say Rain Bird 5000 series on them. I bought 2 replacements and noticed that they are rated at 25-50 foot which is WAY to much distance for the size of my yard. I am curious, how is it possible that the current ones that are installed spray so much lower than the ones that I bought? Even setting them to the lowest distance possible (25ft) on the new ones that is still too far. additionally, I bought some heads that are rated 18-26 ft and the inlet is only 1/2 inch and I need 3/4 inch as that is the size of the pipe that I have in the ground. I am definitely confused... Any ideas?

Thanks for the reply. Just so I am completely sure of what I need, any chance you could provide some links to what I would need? I looked at Lowes and Home Depot and I didn't see quite what I needed based on your response. Thanks in advance.