Well I finally got to fire my double last year, had a blast with it doing the BGR stopper double event.
Only at 50m maximum, so basically not that far.
I have cast loads for my 450/400 which are surprisingly good, only 2 shot groups but they were more accurate than the Hornady factory loads & the Woodleigh's that I've got regulated in it using Reloader 15.
If I needed to do a longer shot I feel I could do it if needed - I'd have to use my red dot for that though! Something I might just try out yet, will have to do some calcs first!