Gentlemens:

Could any of you tell what the typical twist was (is) for a .450-400 3" barrel? I am specifically interested in what would be typical for a turn of the century British single shot, but any information would be most welcome.

Thanks!

Glenn Fewless

381.0 mm exactly 1:15" by CIP
same for both the 3" and the 3-1/4" 450/400s.
Same as the 450 NE 3-1/4" grandaddy of them all.
Quite excellent.

RIP's got it! My Farkies are all 1:15, and that's what I had Ralf put on my Alex Henry, ....shoots all, jacketed or cast, to 1"@100.
Barry

Thank you gentlemen. Your help is much appreciated.

The twist is faster than I expected, much faster than was common in the US at the time for .40 caliber barrels.

I see that Hornady is loading the .450-400 3" with a .410" diameter bullet. Is that also the typical groove diameter of these barrels?

Much obliged for your help,

Glenn

HST

My Krieghoff is .410"

Glenn, .410 is now accepted. In years past the bores went from .408 to .412 and the odd one to .414. It's been the accepted the last few years to settle on .410 bullets and nothing gets damaged. I believe all newer standards call for a .410 groove diameter.

Barry

That's right.
Again same barrel and bullet specs for 450/400 both 3" and 3.25" NE cartridges.
Even CIP agrees with that now, .410" bullet and barrel groove diameter, both are now specified as 10.41mm, which is 0.4098". Yep .410.
Bore or land diameter is 10.16" = 0.4000".
Bold rifling, perfect twist.
They got that one right.

Gentlemens:

Thank you all for your help. I am now on the right track.

Best regards,

Glenn