just curious,  why the qualification? as I recall the hornet,  from past threads here on the site, can actually be pretty high pressure and it concentrated in a pretty small area on the breech face.

Is the damascus in an action sized masses that much weaker than standard "solid" steel?

Beautiful work Bailey.The lever is aspecially classic,and grabs me like no other.Best wishes on your production.Don't forget the Varmit shooters and rimmed cases,as well
Joe O

As for the largest cartridge it can be chambered for. I designed it for 30-06 sized cases, but since it requires a rimmed case, it will need to be a rimmed version in the medium bore family. 

I did some research regarding the specific strength of the action. The dimensions critical to this are the action side walls, barrel band and corresponding barrel shank dia. The side walls are .2" thick, but can be left thicker if requested. ( the action is 1.25" thick)That's the same side wall thickness as a Ruger no.1, but my action has a couple of advantages over the no 1. First is the material. The No 1 is from a casting, and has releived areas where the sidewalls are thinner. I am using 4140 and 8620, and the cavity is wire cut on my EDM. The EDM produces a smooth, stress free cut. The breech block, also EDM cut is a precise fit, which reduces "hammering" from a not so perfect fit. 

The barrel hole on the action is .875", which keeps .2" barrel wall thickness, plus the thickness of the barrel band around the chamber ( .164"). So, the dimensions of the barrel band and barrel shank require the case diameter to be .471" and smaller at the base, The rimm size should be .531" and smaller. This includes the 9.3x74r. So, to answer the question on the largest caliber, the 9.3X74R would be it.

What's not to love.I assume a slide safety will be on the top tang,now if the trigger can be adjusted into the ounces,say from 8oz to 21/2lbs,without some sort of aftermrket trigger,which I'm sure won't be available.Any caliber bases on the 30-30 case would be sweet.My choice would be the 20Classic.
Good luck
Joe O

Now you have me curious. Where would one find a picture or schematic of the Gibbs extractor system?

That is a very nice action. The posts showing the development are very interesting. Wish you the best of luck with it.
Chuck

Chuckster wrote on Mar 27^th, 2010 at 10:03pm:


Look in the Farquharson chapter of Frank de Haas' 1st volume. 

There is an intermediate lever between the underlever and the extractor. The extractor is hinged low, of course. The intermediate lever is hinged high and is swung rearward by pressure near its tip from the underlever. At first, the intermediate lever presses high on the extractor giving good initial extraction force. As the intermediate lever swings further, the point of contact with the extractor switches to the tip of the former, which is near the base of the latter. Extraction force drops greatly, but the speed at which the extractor rotates jumps allowing it to eject.

A similar effect can be obtained with the simple L shaped (bell crank) extractor. In these, the base of the falling block hits the lower leg of the L to rotate it. If the lower leg is long enough and the base of the block is shaped correctly, the initial contact is towards the rear of the block, well out on the lever. As the block falls further, contact is made at the front of the block, nearer the center of rotation of the extractor, increasing its speed of rotation.

Farquharson's original extractor patent was also for a simple bell crank extractor. Its center of rotation changes, a transfer enabled by making the hole for the extractor hinge pin slotted--I'd need to do a drawing. I think the two lever scheme replaced it.

Chuckster, I'm sorry, I should have pulled my copy of de Haas before sending you there. The drawing in de Haas is vague, and the write up doesn't describe the action of the intermediate lever.

Look instead at (You need to Login or Register to view media files and links) It was here I first read the full description of the two lever scheme. It is one of the 4 claims in the patent and is described at the top of the second column of page 2 of the text.

What I called a lever he calls an arm, and his name is more accurate.