At just 200 yards with my NF on 22x, I have a seriously hard time seeing holes in those blue colored targets, sometimes it's downright impossible. This blue happen to be the same exact color as those that are used in 1k BR.
I can see hits on white paper way out there, not sure how far exactly but, it's probably 5 times as far. It's not a BR target but, I see hits on the white steel plates at an easy 1000 yards for the first few shots, then they start to get mixed up with each other... the impacts spots are quite a bit larger than actual holes would be though, that's with 22x, not 42x...
I've switched to white targets I make with just a broad enough black outlined diamond to make it out at the distance I'm practicing at. The diamond helps with POA consistancy and the narrow black outline of it doesn't conceal the bullet holes either. The heavy shaded/colored/lined targets are a thing of the past for me.
Just so happens, my "off eye" is the only one with 20/10 vision the scope eye is at least 20/20 and works.
I have spotted 22-250 holes at 600 yds with my Bushnell Spacemaster "Big Eyes" with 20x
eye pieces. I plan to go to 40x eye pieces
for 1000 yd use. I do not know if I will be
able to spot even .338 cal at that distance
or not but am going to try. I have spotted
6.5mm holes at 600yds with a 8.5-25 Leupold
LRT but it was tough. GEG
Only lens that I have seen that can consistently see 6.5 bullet holes at 1k is a set of the big eyes with the 80mm swift tubes. Jerry Phillips had them at the IBS Nationals in NC last year. Steve Shelp was looking through them and calling everyones groups before they scored them. Cost around $1500 if I remember right.
Just upgraded to a Nikon field imaging system (Nikon 7444) up to 80X zoom and displays on a 4" LCD screen. I am going to the range this morning and trying it out. Unfortunately the range is limited to 700 yards. But I will let you know if I can see bullet holes.
Brent, angled is out of the question for BigEyz. I won't say impossible if I were to concede that it is possible to dribble a football! IF you are talking about a 45 degree which angled normally are, I will say impossible.
The interpupillary distance range depends on the units you are using and some allow a very narrow spread for this distance. You won't know till you try them. I have tried many that would not work if you want to see if I have tried them. (for instance New Leicas and Zeiss will not work at all).
Jerry Phillips had several sets of big eyes with angeled eyepieces at Nationals last year and they worked well. At least one of them was the small back pack sets. The brackets are adjustable for individual eye width also.