From the Buffalo Bore Website....
2nd one down 8b,
2000fps quoted (and puffed a bit at that [magnum?])

To get 2300 you'll have to drop to a much, much smaller bullet.

.45-70 Magnum
Lever Gun

[align=left]Printed Order Form[/align]
[align=center]
Item 8A:
430 gr. L.B.T.- L.F.N. - G.C. (1925 fps / M.E. 3537 ft. lbs.)
(Big game up to 2500 lbs. - Penetrator Load)
[align=center]Per Box of 20
$43.99
Order Now! [/align]
Item 8B:
405 gr. J.F.N. (2000 fps / M.E. 3597 ft. lbs.)
(Big game up to 1000 lbs. - Expander Load)
Per Box of 20
$42.99
Order Now!

Item 8C:
350 gr. J.F.N. (2150 fps / M.E. 3592 ft. lbs.)
(Big game up to 2500 lbs. - Penetrator Load)
Per Box of 20
$42.99
Order Now!
[align=center][/align]Item 8D:

500 gr. FMJFN (1625 fps /M.E. 2931 ft. lbs.)
A non-expanding Full Metal Jacket bullet designed for the
deepest penetration on the largest game animals.
Per Box of 20
$53.99
Order Now!

Item 8E:
300gr. Speer Uni Core @ 2350 fps (3678 ft. lbs.)
(Big Game up to 500 lbs. - Expander Load)
Per Box of 20
$42.99
Order Now![/align]