Home Forums Hunting & Shooting Express Rifles and Big Bores Only The great 458 Winchester. Everyone should own one at least once

Enaa baasee' Sir Bob,



A loaded Federal factory 400-gr TBBC cartridge sitting on manual of the AA-2230 powder company:



If they are truly keeping velocity down to 2250 fps from a 24" barrel, Varmint 73.3 grains sounds about right.
If it were the 1200-R of same appearance (flattened grains of ball powder), I SWAG it would be going much faster.









The partial range of powders eminently useful in the .458 WinMag:





Federal had to trim the brass short by a lot to make the COL same as with old TBBC: 3.315"
2.415" new BrassOL, 2.490" old.
That suggests the ogive of the new bullet is longer.

Old nose projection = 3.315" - 2.490" = 0.825"
Old seating depth = 1.266" - 0.825" = 0.441"

New nose projection = 3.315" - 2.415" = 0.900"
New seating depth = 1.281" - 0.900 = 0.381"

If they load that bullet into a .458 Lott they will have to trim the brass to no more than 2.700" to make 3.600" COL.

Federal is still listing the BC of the new TBBC 400-grainer as same as the old "390-gr" TBBC: 0.353
New form factor + heavier weight + drag from grooves = Same BC ?
Quite the coincidence.