barrel twist for Winchester Model 1886 U.S. Repeating Arms

[swifty]

My Winchester Model 1886 made by U.S. Repeating arms company in 45-90 has a 26 inch barrel. I want to find the twist. I know about using using a cleaning rod and a tight patch to estimate the twist but I would like to see the official data. I would like to plug all this to get the maximum length bullet for bullet stability to to use the known bullet to estimate the minimum velocity for bullet stabilization. I know it will need to be proved at the range but it is a start. All this is done using the Greenhill Formula. It is: http://kwk.us/twist.html.
What is the twist for my rifle?

[Hobie]

IIRC Winchester went with the same barrel blanks as on the .45-70s or 1-20" twist rates in the Miroku made guns. Originally (as when the .45-90 was introduced), twist rates for the .45-90 were slower for the intended use of lighter bullets.

[crs]

Hobie,
Where were you when I was measuring the twist of my Miroku/Winchester (aka Japchester) 1886 .45-90?
However, it was an educational experience and it was 1 in 20", as you say.

Swifty;
Good stuff that you are doing, but if I may be so bold to say it, remember the maximum length from the forward crimping groove to the bullet tip is .48 inch so as to not exceed COL of 2.88 inch. If you want some heavy cast bullets that are certified to work through the 1886 action, check out the Beartooth Bullets web site.

[swifty]

Thanks for the info about O.L and twist information. Length!

[swifty]

Using the Greenhill formula for my RCBS 300 Grain FN Length .802 diameter .461 ,crimp grove to meplat .445 it will stabilize as low as 500 fps. However my goal was to shoot at 1000 to 1200 FPS so the recoil will be less. The part that touches my shoulder is steel! The formula will also be useful to make sure that some of the big heavy bullets will stabilize at low velocity in my Marlin 1894 Cowboy 45 LC.

[1886]

1 turn in 20"or 22". Mine have handled bullets up to 525grs without issue. 1886.

[crs]

Swifty;
I have been shooting 300, 325, 405, grain cast and jacketed in my 1886 and offhand, even strong loads such as Grizzly 405 gr at about 2200 fps are no problem. Note steel buttplate below. Heavy loads from the bench do justify some padding though.

This Marbles peep tang sight (coupled with a Marbles folding barrel sight for close range backup) work well for me.