I would like to add my two cents regarding use of low magnification scopes in low light.
In my experience, the main problem is thin duplex reticule found in prevailing number of scopes manufactured these days. Thin cross hair works perfect in daylight but is practically useless in low light conditions – whatever the magnification.
I once managed to shoot red stag 3 o’clock in the night using rifle equipped with 2.5x scope, only because it had a thick central post in the reticule. The snow helped me to see this stag, but without visible cross hair, 100 yard shot wouldn’t be possible.
At one other occasion, I hunted wild board in Germany, also in the night. This particular hunt was unexpected – we were supposed to shoot only during the day, so I brought a rifle with variable 3-9x40 scope. I could see approaching boar with naked eye but since I couldn’t see reticule at all, I had to pass this shot. Cranking up till full power didn’t help at all.
Roman