We tried the full length 7mm/416, and it is too much capacity in 7mm bore. We actually lost velocity compared with the 7mm/338 Lapua improved. There just isn't a slow enough burning powder available to make this sort of chambering work. The 7mm/338 Lapua improved like Kirby's 7mm AM or our 7mm Super Fatso is the maximum workable capacity in 7mm at the moment. It is superb long range hunting cartridge, that with 869 ball powder gives very acceptable barrel life. Just don't put too much 50BMG down them, that gets rid of barrels real quick compared with 869!
Greg