doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Feeding a BP Double Rifle

My newest project is to get this Boss DR up and smoking. I'd like to use it for deer or antelope next fall. Here's the rub--I know nothing about loading BP. I've only reloaded shotshells. Also, the gun came with a bag full of 444 marlin cases and .43 hard cast lubed bullets which it uses, according to the previous owner. But, the 444 cases aren't an exact fit--the gun chamber mics to .560 at the rim, .470 base tapering, as near as I can measure to, .459 at the neck. The length looks good at 2.225". The biggest concern for me is that the nearest I can mic the bore at the muzzle, it is .41 between lands. With 7 lands & grooves, I don't have equipment to measure more accurately than that. Both bbls were slugged and I have those slugs which measure .429 o.d., but again, with odd numbered rifling, I can't be precise. The rifle is too nice to sit in a safe, and the bbls are in tough enough shape externally (internally, the bores are very clean and the Henry rifling sharp) that I won't feel guilty shooting it. But I sure don't want to blow her up.

Cutting to the chase, where do I start? Thank you!

Assuming you are going to load this rifle with black powder the task isn't difficult. But first get a cerro cast of the chambers to determine exactly what the dimensions are so you can find brass for it. Buffalo Arms Co has a pretty good selection and lots of experience with such issues. Then you need to get an idea of the weight projectile this gun was regulated with. Again you may find Buffalo Arms has something useable. While you are talking to them get a copy of Steve Garbe's Reloading Primer which probably doesn't have your specific cartridge but will teach you how to prepare such cartridges. Not much in the way of tooling is needed. About any rifle reloading press and a set of dies will do it. Also look around your area for groups shooting Black Powder Cartridge Rifles (usually silouette shooters). They are a good source of a mentor or two as to win they have to have figured this out already. To make the process go easier you are going to want to find some FFg Swiss rifle powder. The more common GOEX is not quite as well suited to cartridge applications in my experience. You might also choose to use Pyrodex powder but be aware it is very corrosive.

Pick up a copy of Graham Right's "shooting the British double rifle"....lots of info in there on how to get your double up and running.
Steve

K. Crowley, by the stamps on the tubes you may know that it has Alexander Henry rifling and here are a couple variations in his U.S. of A. patent #119846: http://www.google.com/patents?id=kU5rAAA...846&f=false

Thank you for the leads. Is the chamber casting something I can do on my own, or is a Smith required?

ellenbr, thanks for the link. I wouldn't have thought to look at the U.S. Patent office.

You can do the cerro cast yourself if you wish. The metal is available from Brownells and I believe there are instructions for it's use. It isn't hard to do.

Can you direct us to your photo hosting service for a higher definition photo of the barrel flats and barrels? There really ought to be some caliber data on there but I cannot see it from the photos on this board.

A great place to start is over on the Black Powder Cartridge chat site: http://bpcr.net/. Some great information over there and a lot of folks willing to help.

I don't know why my images are so small here? The photo is stored at Picasa, is bigger (1600x1087) and usually posts fine on other sites. For some reason, this site scales the photos much smaller. If you right-click and look at properties, you can see the info and the original link.

But, there doesn't appear to anything related to caliber on the flats or the tubes. I'll upload it to a different host and see if that helps.Here's a link to the original:

Boss Barrel Flats

Update: Something here at this bbs is preventing the images from displaying larger than 400x267. I tried linking to the image through another host and the result is the same. No idea why...

There's more than one way to skin a cat. Here are all the bbl marks, minus the ser. # and the initials "JP" on each tube. The watertable only has the ser. no. and the Crown over V proof. Nothing to help on the chambering anywhere, unless you see something I don't.

I agree, nothing there to indicate chambering. Another thought is whether the manufacturer's records are still available for this rifle. If so they would be able to tell what it was originally including bore diameter and especially the projectile weight for which it was regulated. That last item is going to help a lot in developing an accurate load which permits both barrels to print together.