A friend just picked up a W. Collath 20 ga double rifle. hammerless gun, with the break open lever being an ecentric under the forend. It draws the barrels foreward until the "pins" clear the breach and then breaks. very interesting design. It's chambered for a 1 7/16 inch 20 gauge shell, a metford or some such rifleing... different looking. Anyone have any idea of what the weight of bullet it would have shot?

That sounds very interesting!

I have a 20bore Purdey. I run roundball and 2-1/2 drams Swiss 1-1/2F.
It was typical that Purdey (and others) would recommend ball *or* short conical.

Here's a load recipe from a Kavanaugh 20bore side by side cartridge rifle.




That load would likely fit in your friend's cartridge cases.


Can you get the bore/groove measurements and rate of twist from his barrels - and post them to the thread please?
Also (obviously) I'd love to see some photos.



Cheers
Tinker

I'll have to check on the twist rate... photo's will have to wait until he comes home ( damn retired friends!) But I'll do my best, thanks for the info, it's a start!

B40


Just want to note a couple things on projectiles.

First thing is to note the strong suggestion he focus his load development on roundball.
At the velocities the rifle will run at *and* considering the relatively short conical that would (if at all it were) be appropriate for this rifle - roundball will penetrate more consistently and predictably than a conical would.
Also it's going to be much easier for him to get a ball mould made (Jeff Tanner from the UK is the key to quick and low-cost success) of the right size for his rifle.
He'll want to run roundball of a size approximately .003" - .006" over groove size.

I very much look forward to hearing of his efforts in load development - and hopefully of his great success and satisfaction!



Cheers
Tinker

Tinker,
I dug out an old Lyman 575494 hollowbase mold I have. It looks like a crayola crayon straight from the box, if you can picture that shape. I wonder if that could be opened up to the rifles bore dia, a new plug could be made to make either a solid base, or hollowbase with the plug it has. What do you think??

B40--

quote:

Lyman 575494...What do you think??

My first thought is that he should try roundball.
Conical might end up working, but as a hunting rifle the roundball is a better choice, with better velocity (trajectory) and straight-line penetration. Also, by a great margin, most bore-rifles will regulate with roundball.

Bullet shape -- there's really a lot to bullet shape and how a double rifle works. Have you or your friend ever owned or developed loads for a double rifle? Bullet shape and weight can have great influence on how a load will or will not work in a double rifle. Back when that Collath was built there was roundball (elegant, simple, effective - popular) and there were numerous schools of thought on 'other' bullet design.


Here are numerous antique bore-rifle cartridges
The very last one (sectioned pinfire) is a pistol cartridge that I put here to show the hollow-base. I only put it here to give you an example of what *not to do* with this rifle. It is unlikely that a hollow-base bullet will work with the bore-rifle.















This is the mould you speak of.



It's always possible to get the thing in a 4-jaw and hack it to the point where it'll throw a bullet that'd function through the bores of your friend's rifle.
The question is whether or not the rifle wants a conical in the first place.
You can spend a lot of time hacking a lot of moulds on the way to finding out what will end up working - or you can start out with roundball, which is the most likely projectile after all.



Cheers
Tinker

Tinker, you have me convinced, as your knowledge of thses guns is far past mine. I enjoy the load work-up, but it's nice to at least have a starting point.
Would you be up for a phone call about the gun/load possibilities? It would be appreciated if not to much trouble.
My e-mail is .. skieter@myfairpoint.net if you are interested in sending your phone number.
thanks,
Tony

B40


Note that I've only worked up regulation loads for a few antique bore rifles - not the most experienced guy out there, but I'm happy to share what I've come across along the way.

You have email, daytime is the best.



Cheers
Tinker

B40-

I spoke with your friend on the telephone yesterday, suggested he do chamber castings and slug the bores - then join this forum and speak to this thread.

I'm very much looking forward to seeing what he comes up with, photographs would be great!
This is the best place to continue the conversation, as there's a big community of guys from all around the globe who can see what comes up and help in the process of getting him set up with loads that get the little Collath shooting to the sights.


Cheers
Tinker