doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com 12 bore pinfire WR

Gramps-

Tell me how you have your photos stored on your computer or what website they're stored on.
Later in the day I'll be able to give you a hand with getting them up on this site.


--Tinker

they are jpg's. just took some today. i could email them to you. i once had your email, but i can't find it now. heating up some cerrosafe now.

Tinker,
Success. Two good chamber casts. 1.6 inches from the rim of the cartridge until the chamber necks down. There is then a .2 inch smooth area until the rifling starts. The wall of the chamber is .78 inches in diameter. The .2 inch smooth area after the neck down, and prior to the start of the rifling is .72 inches in diameter. It has 8 lands and grooves. Groove to groove is .715 inches. Now what do I do?

Gramps

Wow Gramps, way to go!

What's the rim thickness and rim diameter?

Is the chamber tapered? I'm guessing it's bigger in diameter up by the rim (base dia) than at the case mouth.

For your photo posting excercise, we're going to have to get you set up with an account on a photo hosting website.
I use flickr.com and it's super easy.
just go with them or do a web search for free photo hosting and choose one.
The thing here is that it takes server memory space to show a photo on a therad like this. when you see an image here on the site, what's happening is essentially an elegant linkage of resource.

Start by getting set up on a photo hosting site. It's super quick and easy, the process will be explained at the website you choose.

Then I'll walk you through showing them off here...


--Tinker

Tinker,
Just thinking about it, half the diameter of a .715 ball is .3575. The chamber length plus the .2 inches of smooth wall prior to the rifling is 1.8 inches. 1.6 inches of chamber, plus .3575 inches of the forward half of the ball sticking out past the neck of the cartridge equals 1.9575. Since it's 1.8 inches to the start of the rifling, and the rifling gradually increases its purchase on the ball, and the ball is round, that should put the face of the ball sitting right on, or near, the start of the rifling which might add to the accuracy of these fine arms. So you're experimenting with modern, plastic hulls? I am considering cutting some high brass hulls to 1.6 inches, placing them in the chambers and marking the hole for the pin. What I don't know is how the cap goes inside the case. Do pinfire cases have some kind of anvil inside to rest the cap on? Does the pin rest inside the cup of the cap against the priming and the case wall acts as the anvil? I think I can figure this out. 20 years of shooting blackpowder, and another 15 of handloading should prove useful.

Gramps

Rim diameter and thickness...
Will a cutdown modern case chamber in this gun?
Typical pinfire cases have very thin and slight rims.

Also, you'll likely need to look at a few different modern hull designs to find one that'll hold enough powder, modern base wads are much taller than the old pinfire cases -- high brass just isn't necessary.
The closest thing I've seen to looking like it'll work is the Activ all-plastic one-piece hulls.
Not glamorous, but very strong and lots of powder room.

Oh, another thing.
Don't load these with the balls touching the rifling. Some jump is actually good. Double rifles typically perform best with some jump.
One thing to consider is how the 'second shot' barrel will do with the recoil. You don't want the second roundball sticking in the rifling before it's fired.
Also a little jump can help keep pressures down.



--Tinker

do you just slide the cap down the case and seat the pin in it? do you seal where the pin and case meet with some kind of cement to help prevent inadvertent firing? so many questions.

I set my brass cases up with central anvils for the caps, although I don't really think it's necessary.

For the firing pins, I use a tiny bit of thick crazy glue and set it with accelerator. Just enough to hold the pins while I finish loading the cases.
I think the tamped-down blackpowder does a good job of holding things together in there once all's done.
oh, and yes, I just slip the caps in there with long tweezers. nothing to it.


So rim thickness--
does this rifle need thin skinny little rims or will modern hull rim thickness work?


--Tinker

Central anvil? Remember, you've got to talk down to the Marine. I'm going to got down a shotshell to see if I can fit in in the chamber, and then I'll know about rim thickness.

Ok, you were right. I just spent an hour creating a beautiful case out of a high brass, 12 gauge shell. The rim is too thick so the action won't close. as well, the plastic walls are too thin to hold the ball, it just falls into the case. So i guess I need to have some cases custom turned.