Peep sights??
I've used a couple different peep sights for nearly 20 years. On more than one occassion, the use of a peep, in low light conditions, has prevented me from being able to take shot in the fading minutes of the evening. Even enlargening the sight hole hasn't helped much in most cases.
What do the most of you do to prevent this? What type of peep would you recommend or what modifications might prevent this??