A TSX in 300gr. would be quite surprising in the penetration department, expecially if driven at top speed from a .450/400, I'd wager. The .405 Winchester would be no slouch, either.

As to max loads for the Ruger with 400's in the .405 - you could easily best 2,000fps, maybe 2,100fps in that rifle.

My data shows 1,945fps and 1,928fps at only 44,900 and 44,300PSI. In the Ruger, that case can make another 12,000psi. That would give a substancial boost to the 'old' round.

Considering Benchmark will drive a 300gr. Hornady at 2,400fps at only 42,200PSI - my earlier guestimate of 2,400fps was considerably low.

What game is the Hornady bullet designed for? There is always the TSX, Swift and others.

There are no flies on that round.