Whitworth bore ??

idaho cowboy

How were the hex bores on the Whitworth rifles made? Were they forged or were the hex flats milled into a round bore? or ??

rufe-snow

Years ago when I worked in a machine shop. When we cut ID holes with flat sides. We used a specialized cutting tool, called a brooch. It started out round, but each successive cutting surface changed it to angular from round.

Besides the brooch cutting tool itself. A special very sturdy high pressure machine was required. To force the brooch cutting tool through the steel.

This is the only way I can envision the Whitworth rifling, to be cut.

MIKE WISKEY

that's pretty much how 'cut' rifled barrels are made, broach cut with a 'twist'

navc130

An interesting question that I have never seen answered in years of reading. However, in investigating the web sites for Whitworth Rifle, my opinion is that they were rifled in the conventional way but the rifling cutter cut a flat plane instead of a groove in the round bore. It is possible that sucessively larger broaches would also do the job: a broach cutting all the sides in one pass. However, I am not aware that broach rifling was done in this time period.

11echo

Try googling "button broach rifling" ...you'll find you answer.

Hawk Carse

Agree with navc130. Conventional cutting with a different cutter setup than for grooved rifling.

Mr, later Sir Joseph Whitworth was pretty sharp but I do not believe there was the capability for broach, button, or hammer forge rifling in 1860.

Mr Garand designed the M1 around broach cutting, which was the new technology of the 1930s.
I think the Germans were doing hammer forge rifling as early as WWII but it did not get a lot of notice until Steyr started selling rifles with the forge marks still on the barrel.
I don't know who was the very first to button rifle but Mike Walker at Remington and Douglas were the ones to make it stick.