500/416 Double Barrel Rifle

Hi Guys
I was thinking of getting myself a 500/416 double barrel rifle for the big 5.
Question. Which one load only should I use ( the 410 gr or the 450 gr from Norma or other ). I like to get one load and sight it in for the life of the rifle. Also, why was the 500/416 ever invented. What's the advantage of this load compared to the 416 Rigby or the others.

Personally I'd go with a more standard caliber like the 450/400, 450, 470 or 500 Nitro's. They'll do anything you need done.

First and formost, I suggest you would have to shoot the 450 gr. Woodleigh in any double and find out if it will regulate and sight in, in YOUR gun, if so then its a killing sucker.

I love the 450 gr. Woodleighs in my bolt action 416 Rem, it ups the caliber to probably a 458 Lott in killing effect or so it appears to me from the reaction of hits on buffalo???? BTW the 450 gr. Woodleigh PP is heavier constucted than the 450 gr. RN, thus penetrates more, best for dugga boys whereas the RN is best for herd hunting buffalo where you need to limt penetration. BTW I helped Woodleigh design the RN, he then added the PP, and it's a better all around choice, but doesn't have the nostalgia as those big RN bullets have..Either is a killer for sure and I have shot a substantial number of buffalo with both.

As to the caliber, it should be great caliber and I really like 40 caliber big bores. Some have told me that its recoil is the same as a .470? if that is so and it should not be, then I would opt for the wonderful 450-3.25, my all time favorite double rifle caliber if elephant are on the agenda, otherwise I would opt for a 450-400-3"...All opinnion however and such choices are an individual thing.