Loiter_Turns Radius

Thank you for all.
I am simulating Mission Planner along with SITL, but I have something problem with Radius on Loiter_Turns in Flight Planning. I found that even if I put 500 Radius and write to SITL, it doesn’t flight like that much distance. finally, I found that even though, I write 500 Radius to SITL, and if I read it from SITL, it is 244 Radius rather than 500.

If anyone knows about the matter here, advise me, please.

Thanks…

Which ArduCopter version? What units are you using ? cm? m?

Thanks for your response.
The unit is a meter.
and the version is following,
ArduCopter : 4.1.0 (1c4873ce)
Mission Planner : 1.3.74.1 (build 1.3.7681.3767)

Please retest with version ArduCopter 4.0.6-rc1