doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com Sixteen bore, double rifle, pinfire...

maybe have some time on the next weekend to make pics. a CNC lathe is great, you can make all kinds of cartridge systems. for pinfire cartridges you find so different ways to prime the fired case again. A little door on the side, base and tube fiting together with a thread and more.thats because we collectors classify the pinfire cartridge under "patent ignition systems".
i dont load a wad under my plinking roundball load but this is in a short case( hold only 65grain FG). When you need a real good cartridge for a shotgun barrel with 65mm long chamber load allways a wad under the ball. the short rifle case is not intendet for a wad, you need all space in the case for powder.

With as large a flame front as the sixteen bore will have I wonder about leading when shooting without wadding.

Looking at British proof loads from the time this gun was made, it seems as if the proof load was 75 grains of powder. I'll have to look again to see just what powder they were using, but I think the documents I was looking at stated 75 grains for ball or shot at an ounce of either at sixteen bore.
That would make sense with the powder measure this gun came with will throw 75 grains at the setting that I found it at and with the cork plug in the base of the measure.

I'm also interested to hear about what the typical practice is in respect to bullet jump.
Should this gun be loaded with the ball touching the rifling or with a little set back to allow for a bit of jump?
I have the sense that with black powder, it'd be best to have the ball touch the rifling.
With the paper cases, it couldn't be set up to engrave the rifling, the paper just won't hold tight enough.
I've seen crimped brass bore rifle cartriges loaded with ball, I'm sure that makes them much easier to care for in storage and in the field, but it seems it'd be a bit of a task to set up crimped cases for ball that would engrave in a nine groove rifle.

As I'll be building metallic cartriges, and will likely stick to ball loads unless I hear of a good conical for this system, I can set up to load ball in a light friction fit and still touch the rifling, given that I taper the outside of the cases at the chamber throat end of things.

I don't have a website to post photos on, so if I do photograph what I have here, I'd just have to send them to you if you wanted to see what's going on here.


so.

Is lead buildup a problem when shooting without wads? Do I engrave the rifling, just touch it, or set up for a little bit of bullet jump?
What's the best way to go for this big of a bore and charge of black powder?

The .577-450 Snider military round was loaded with a paper sleeve in the case to reduce its capacity appropriately. Your cases seem to have a similar sleeve, albeit not paper. My inexpert guess would be that it would be good to measure the volume of your cases and duplicate that volume when you choose the weight of metal to make your new cases. The appropriate powder volume would be that required to fill the case below the ball.

I would also think a round ball would not require a wad. The very shape of a ball spreads the heat over a larger surface than the base of a conical bullet, thus avoiding the melting/vaporization that causes leading. Recall that muzzle loading rifles use only a cloth patch with a round ball, sufficient to engage the rifling but of little use in protection from heat.

What a wonderful gun! You are very fortunate.

P.S. Graving rifling with a bullet, especially one lightly crimped, is usually a recipe for a bullet left in the bore if the unfired case is extracted. I'd back off a little.

Modern rifles usually like a little jump, but not a lot, but it can vary from rifle to rifle (according to Don Zutz). I'd leave about .005" leade and see how it shoots. BTW you are also probably in for a lot of fun trying brands of BP to see what the rifle likes. Whatever it was regulated with is certainly no longer available.

Aaahh yes, the patched ball...

I have the patches from the first few rounds my father fired through his custom squirrel rifle.
That thing's beautiful, it was made at the Thompson Center custom shop, it was finished just before the place burned to the ground.
The barrel has the most beautiful high polish blue job I've seen on a gun in quite some time, the wood is unbelievable.
That little thing's a small bore gun, and the patches are for the most part fully intact.

I'd figured this gun with it's much greater bore would punish the lead and somehow deposit the pains of said labor on the bore. Thanks for the note there.

I'd been looking at musket loads too to compare bore/bullet weight/powder charges. Most things seem to point in the 75-90 grain neighborhood.
Tonight's my night to do volume/weight comparisons between the fired cartriges I have from this gun and the powder measure that came with it.

My plan with the metallic cartrige design is to look at the Sharp's patents, study what pinfire hulls I have here (ten or so assorted hulls, most unfired) and consider overall volume and bullet seating issues in my initial drawings.

I also have some concerns about gas sealing in the chambers. With paper hulls, like those this gun seems to have been built for, the casings essentially 'inflate' and swell during the time of combustion. This action tends to be enough to keep, for the most part, the pressures of combustion from escaping through the breech end of the gun.
Brass cases are typically designed with rather thin case walls in comparison which have little trouble ballooning out to seal the chambers during ignition.
If I build brass case walls thick enough to emulate the shape (and so also emulate the volume of...) of paper hulls, I may end up with a cartrige that is too rigid to deform enough during ignition to seal properly. Or I might not.

So far, the design notions I've come to over discussion with my closest associate here at the shop is to build the cases in a two-part process.
This is to make the interior of the case head and webbing of the cartrige easier to machine (long reach + skinny cutters = tool chatter) and more economical in the long run as I won't have to spend much machine time or material on boring the bulk of the powder room of the cartrige from solid stock.
The case heads will likely be made from 316 or similar stainless and the case walls from brass, the pieces silver brazed then finished after brazing.
Stainless for the heads so it won't anneal during brazing, and brazed instead of threaded for greater durability. We're thinking of running a removable primer pocket and a nice little tool to make repriming easy.

My thoughts on wall thickness and interior architechure have been 'run it thick and have relatively straight interior walls, easier to run wadding if necessary'
I've also thought of running a slight hemispherical (hemitauroidal might be a better way to say it) seat ledge near the mouth of the cartriges to allow the brass to support the seat of the balls against the rifling, I wouldn't expect a thick-walled cartrige to stretch, especailly at the relatively low pressures expected with this rifle.

Much to consider really.
Still at this point I'm doing some homework on the proofs on this gun, and my proof book has gone missing. I'm feeling rather dead in the water without it, but really, the standard guide of proofs is often not nearly enough information for the stuff I end up looking at.
Someone should have a few pages of proof marks images on a web site out there...
grrr...

I may end up in the machine shop tonight turning out a couple of prototype stainless case heads, if I have the right brass tube stock, I might even turn out a couple of complete cartriges.
If I end up doing that, I'd be in serious need of an all-night testing range or soome very good sleeping pills in order to hold me over till the sun comes back up in the morning.
I have a sense once I have metallic cartriges for this gun I'll end up needing to fire it in short order just to satisfy my curiosities.
heh heh heh...

look at your PM, I need you e-mail address

Got it, check your mail for an address.

Also of note, last night while fiddling with the shotgun barrels for this gun I discovered they're choke bored, .005" and .009"
Hadn't thought to even look before as I figured the time of this gun preceeded the days of choke boring.
Cool...


--John

hope you got the mail with the pics, have some more on http://www.imagestation.com/album/?id=2132163281
if someone here can say my how to bring it on this website.

Tinker, You need to look at the thread titled "Mag-Tech Brass" over on the shotgun page. A chap who calls himself Jeb Stuart quotes a source for all-brass pinfire shells. The name he gave is "Hammer Double Co". Many of us are waiting with bated breath for him to come back with contact info for this supplier.

Tinker try this site. http://www.premiermultigauge.co.uk/docs/proof.pdf

Thanks guys-

I've been busy lately, buried in the barbed wire of a nasty schedule and juggling through the catch-as-catch-can ergonomic adjustment from my (for now dead as a brick) PC to this mac laptop a friend gave me recently to tie me over till I get my desktop rig back up and running.
I'll try to get some photos up somewhere to show some of this nice gun and the work I'm doing building some rather pretty cartirges and loading tools for it.
I'm going the -engineered for my own darn love of pretty things- route in setting myself up with ammunition.
I've seen cases made from standard modern ammo with spent 209 primers hacked to take normal centerfire primers on edge, inside the cases, running pins through nothing more than a hole through the side of the brass and plastic case.
Ultra simple and without a doubt effective as anything else could be.
Instead of following the well laid path of my contemporary fellow enthusiasts, I've casted the chambers of my gun and am building cartriges with steel heads and rims with brass walls turned specifically for these chambers, the projectiles that I'll be running, and the volume of whatever powder I settle on in the end once I've fired it through testing and regulation.
I'm going with smal primers, this gives me a range from standard small pistol through mag pistol, small rifle, and on into the range of match grade small rifle primers.
I'll hsve some choices there to get something to flick the black powder to life, while having plenty of room in there to pull and reprime the brass either in the field or at the bench.
The primers are to be set into simple inserts, the little primer pocket inserts will be easily set or removed with an elegant tool that won't look funny sitting beside wood stocked turnscrews. That tool will actually look quite a bit like a turnscrew.
I want plain smooth heads on my cartriges so I can have more freedom with head stamps or engraviing on my ammo.

For the first ones the case heads have been milled from steel, the run of production I'll do for my kit will likely be done in 316 stainless.
Steel for the heads so it won't anneal during brazing, brass for the walls, and silver to join them.

I have a 24 and a 32 bore gun to feed as well, those are also pin fire, and the inserts and tools should run fine in the smaller cases without any trouble.


--John