Originally Posted By: DoubleUp
Sounds like you had a defective unit. Even a 19A will do deer at over 500. A 640 core should have been much better than that.

It is a very good possibility, I never heard back from Pulsar engineers. Deer at 400-450yds would "pop" at that range with my XQ38...then I would switch to the XP28 and could barely tell if something was there. I was using black hot and white hot with both.