Brithunter is right on with the better scope idea (Naturally, he is British after all!).
If you have the money, Leupold has the option of a German #1 post , on a scale of one to a zillion, this gets top marks for seeing in dim light, even on low power settings like 3X. The VX-I & II's and the older Vari1 & 2's can have this installed.
On a budget, the Elite 3200 with their 3-2-1 reticle is very good also. I use both (in Germany!) and would be perfect on your .243
Jon