My good customer in NY thought this project up. He always wanted a sidelock double rifle, but just cant afford the real deal. As he put it, "I'm a Toyota kind of Surgeon". The caliber, .500 Linebaugh is a revolver cartridge. Being low pressure and small case it can go on a smaller action size, this one being a 20ga sidelock. Consequently being such a large bore we should have a pretty lightweight piece. It will be a great driven deer rifle and close range pig gun.

The barrels started as blanks, all contoured by me. Only having manual machines I have to get creative as you will see. The barrels taper from the monoblock seam(.900") down to .700" mid barrel.


The "steps" are removed by hand filing/striking. One must be careful not to washout at the bottom of the taper into the straight section.:


To affix the barrels into the resulting monoblock we shrunk fit them in. This was my first time doing it this way...nerves were shot by the end of the night! The seams at the breach end will be TIG welded, the seam at the front of the monoblock will be micro-tigged. One thing I am not is a welder, so I'll have it welded before installing the ribs.




Here is the actual size drawing. Im still playing with the grip area. The blank we picked out is a Turkish blank from Luxus.


Before inletting I wanted to really clean up the insides and outside of the actions. To do this I needed to anneal the action. The action will be CCH at a later date. Just some random polishing pics.

Great Project! (the caliber: http://ammoguide.com/cgi-bin/a...BEqstFNKYn&catid=423 )

You turn out some interesting stuff. Keep em coming.

VERY cool, love the projects and pictures.

Very cool project. My .500 Linebaugh is on a Bisley platform, but I can attest to the cartridge being more than adequate for deer, hogs, elephant, lions, and tigers, and bears oh my!

+1 very cool project, I have my 500 on a bisley as well. with 525's, that gun will stomp anything on this planet.
Look forward to seeing the progress.

With pressures in mind, would going to a 500 Max (1.6 version) be to much for that 20 gauge frame size?

Very cool project? What action did you start with? Are you shooting for a certain finished weight?

Outstanding idea.
Any estimate about the total cost?
This could be a real fun gun.

And I'm headed to AK again for bear in May.
Probably too late this year to commission one?

This customer will have $8500+ into the gun by the time it's over. That being said we are putting a lot of work into it. Full shotgun to rifle conversion, full restock with a nice piece of Turkish, annealing and re color case hardening the action, cleaning up the lockwork, gold plating some of the internals, and more.

It can be done cheaper or more expensively. The hardest part is finding an adequate 20ga donor gun.

This gun is an off brand Spanish gun, a copy of a h&h action. We went with the more modest 435grain load going 1000fps. If one wanted the more potent rounds we could step up to a 16ga frame. I know where to get some JP Sauer guns, overall for the gun and the conversion work would be around $3500. I couldn't have it done by May though, barrel providers are too backed up.

It would make a great Alaskan round for bear and moose. One could have a sidearm and a longgun in the same caliber which is what Carlos(customer) is doing.

I wonder if a 460 and 500 S&W work in this application? Would make a good Hogs rifle.

Your starting to play with some serious pressure on those two.

What's the optimal barrel length for this load?

Looking forward to seeing the final result, looks great so far! Can I ask how much oversize you leave the barrel tenon before shrink fitting?

Getting close:

Still have all the lockwork to inlet. I'll just knock it out one piece at a time. Someone much better would do it all together. Alas this is my first sidelock. Done plenty of boxlocks.

quote:

Originally posted by big will:
I wonder if a 460 and 500 S&W work in this application? Would make a good Hogs rifle.

The SAAMI spec on those two cartridges is the same and just under 62,000 psi. The .500 Linebaugh tops out right around 40,000 psi but you don't need to load it that high to get exits on very big animals (loaded correctly of course).

I am glad you are doing these. I see you as the next DR master maker, in the US; hopefully the world.
On the .50 calibers; you could use a longer case, like a 50-110, and get better velocities at lower pressure. Those little pistol rounds can be hot. Just for future reference; noting wrong with what you are doing.

Wow! Thats a really neat project, and its going to be a gorgeous gun!

That should end up being a very capable and interesting piece!

Stock roughed out, still a lot of refinement to do. Pictured with the original forend wood.

That is going to be one beautiful rifle.
Waiting to see the finished product.

great lines Aaron!