I always did think you put that title too strongly. I would call it no more than eccentricity.
Printable View
Bearing mind that the Chassepot is a weapons system, so each part of the cartridge/bolt/chamber/bullet is designed in relation to the whole, a bore riding bullet makes sense to the original concept and purpose as it lets the fore part ride on fouling and only had to engage the rifling with the rear portion. Not that it means it is the most accurate choice, but that it was a right answer to the question of a military rifle at the time.
As you are looking to maximise the non rigid case Chassepot concept two things come to mind to me FWIW (very little).
One is that your modern needle probably can cope with a Dreyse style primer at the bullet base, passing through the black powder charge. This reduces the importance of case rigidity.
Another is to wonder if one could take another approach and experiment with a caseless charge of coarse grained black powder bound by thin (4% in alcohol?) shellac or a collodion with the primer set into the rigid case and the bullet glued onto the end in some (denser shellac?) manner. Not a round that would be robust enough for military service but one that would be fit under match care standards. The key here is taking advantage of the Chassepot needing neither an obturating case nor extraction. Of course one would need to consider if the residual shellac or collodion would flash the ignition too fast through the charge and cause a dangerous initial spike of pressure. Here I go well beyond my competence.
BTW where did you get your Chassepot parts drawings?
John
Right guys.
It just might be...that weīve unveiled something here.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
So what i did was turn a "master" on the lathe right. Subtracting the thickness of the material from the overall diameter of the master. Using the stock bottleneck...just disregarding the twin angles and making that into one angle over those 3mm in the stock drawing where it goes from 14,5mm downwards. Shutter angle all in all 22deg.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Master out of 7075T651 aluminium,meaning itīll stand for a while no worries.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Sprayed it with regular WD-40 before heating/fireforming the shell with a regular heatgun....
https://www.youtube.com/watch?v=ZQXl...ature=youtu.be
..n here ya go lads.
The mere fact that we now have a cartridge that registers on the bottleneck brings a few very usable features. First up we can set bullet depth to basically where ever we want it to be. We can toss n turn as far as bullet type until the cows come home.
That brings that need be we can design for bullet jump and/or interference fit with any 45 cal bullet thatīll fit the bill.
Now. Please keep in mind that when filling that shrink sleeve with powder,grease cookie and whatever..itīll only get more tough.
In turn the close proximity to the chamber wall will increase toughness even more as itīll make it even harder for the cartridge to fold in any way possible.
In essence?
From the looks of it it sure looks like we have a winner. This was the second type shrink sleeve i tried,and as the *** i am i of course forgot to write the numbers/manufacturer for it down..no fret tho..info is just at the work table of mine at the shop.
IF i got it right this particular shrink sleeve works on a 3:1 bias. Ie;itīll turn three times as small vs its original diameter. IOW approx shy of 5mm worth.
Thatīs kind of academic though as the REAL question is if itīll shrink FAST enough. Only one way to find out i guess...
I think Jesper here may have dethroned me. This may very well be the highest example of the Jurassic Park Foreboding - "Just because you CAN doesn't mean you SHOULD" - that I've ever seen. But dang if this isn't turning into an interesting show! ROCK ON SIR! ROCK ON! :awesome:
Yeah. I think he's on to something with shrink tube matched to what is essentially a chamber casting - at least as far as accuracy goes. How it does for expulsion? Let's solve one problem at a time.
Or just because you possibly can't, doesn't mean you shouldn't.
There used to be a vogue for wrapping grooved and lubed bullets in Teflon plumber's tape (PTFE in the UK), and shrinking it with gentle heat. It was banned for some classic target-shooting in the UK, and there is nothing like a ban for convincing people that something must be good. I probably know its origin, for in Clyde Williamson's extremely good "The Winchester Lever Legacy" he illustrates his own patent application.
Some years back therefore, I searched eBay for Teflon tubing, and bought some, which was much thicker than the filmy plumber's tape. Unfortunately I found that it was too uneven in thickness to position a bullet precisely enough on the bore axis. I will find something else to do with it, one of these days. Of course current production or other brands might be better, and not all heat-shrink tubing is Teflon, although that is surely the strongest.
I'm intrigue by the process, although I have some doubt whether it would be consistent enough for rifle use. Mounting the former on an electric screwdriver, to produce even heating on all sides, might help. It would surely be usable for someone with a problem feeding an 8ga or 4ga shotgun.
@Bigslug.
Thx!
You guys are already aware,but the possibility of registering the cartridge on its bottleneck for a Chassepot cartridge does hand us a crapload of leeway. Really.
Granted that it will become a matter of shrink sleeve consistency,and the only way to pursue that for a fact is to check loads and loads of it i guess.
To the point where itīll become part of the loading process to check goods thickness for every time you pick it up?
I doubt a few hundreds (millimeters) will make for any appreciable difference in performance, while tenths will. Or? Point here is the actual angle between the two diameters that i aim to register these bullets/cartridges on.
That brings that main chamber fit will have to be rather tightly controlled,just as with a regular brass cartridge. OTOH,within reason,as long as that bottleneck is of uniform angle and measurment..i dunno. To me at least it stands with that fact.
But this bring a whole array of other question marks that needs to be made into exclamation points. Not least the fact of how to handle the added room a cartridge like this will hand us.
Filler of some sorts,sure..
Would it be an added benefit with shrink sleeve that holds glue (thinking bullet here)?
What i have in mind ATM though is something completely else and that is to turn a sorts of holder for the primer where weīll be able to turn the cap "the right way around",and do this using blackpowder primers. Ie;sans built in anvils.
Ie;musket,revolver..whatever,but a cap designed for cap n ball use.
This will present several issues that needs to be handled,none the least how to make such a holder fold,or whatever,to be able to evacuate as the shotīs been fired.
Current thinking is a straight forwards plastic such where i glue a very small piece of brass tubing within the cap,yes..cumbersome for each cap,to work as an anvil.
Said holder will almost be sawed through,leaving like a mill at the utmost bottom of it. Insert cap and superglue in place...
Small piece of tubing will come to an absolute halt at the bottom of the crevis/hole drilled for the cap,and thus work as an anvil.
As the holder is sawed through from the cap end itīll "fold" as a pair of scissors, sort of, and in essence just grab the cap even harder as the firing pin hits it.
As the powder ignites however thisīll excert pressure the opposite way,and the holder will fold in two,being sawn down the middle as it is.
This whole process,have looked into it,sounds way more cumbersome and explicit than it is,one of the design goals here being simplicity.
Only part of it thatīs not is really the use of a piece of tubing within the primer.
I even bet such a holder could be cast at very low cost if i just built the tool for it. Even know a couple of guys that works at such a plant...and with the tool in hand these guys donīt really care if we ask for 50 or 50 000...
Then again..i guess we could still revert to the original manner,just modernize it a bit by omitting the "cup" for it aso and just add a rubber disc at the absolute bottom of the cartridge to act as a "broom".
Point being that iīm unsure if the stakes are worth it (time) to look into such a holder in greater detail. Turning a few on the lathe of mine is sure doable (prototype work IOW) but the question is if thereīs a point to it really..
This comes down very much to original diameter of the shrink sleeve used. Hence why i opted to use a sleeve that would just baaaaaarely slide onto the master piece.
That brings that as i apply heat the actual shrinking of the 14,5mm part of it very very limited. What it DOES do is harden the plastic though.
In essence selecting the closest diameter we can just brings....consistency.
To us the law states any gun made before 1890 thatīs not intended for use with a sealing cartridge is exempt. That ALSO brings firing the pieces and all that goes with it.
Thus powder,primers and what not for these guns are exempt as well.
We,as a group,are trying to get that last "not intended for use with a sealing cartridge" struck out of the text. TBH itīs kind of moot isnīt it?
Guns made up until 1890 are mainly all blackpowder why one can certainly question that part of the sentence. What difference does it make if said blackpowder is fired from a cartridge like the shrink sleeve one in the works here or an old paper/brass 12ga one?
Really.
Just BS law mumbo jumbo if you ask me,but the law is the law and law abiding citizens we are...
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Indeed. A bouquet of shrink sleeve. Whatīs there to add?
http://iloapp.elegic.com/data/_galle...00_resized.jpg
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Hm. Of course i bought the wrong,ultra high,rings. Point being that i needed to fab risers to make the rail clear why..if of course need ultra LOW rings.
That be ****ed tho...weīre getting there boys...
That brings up another question,which is specific to me. How much will the chamber take of a Chassepot rifle? From the looks of it at the moment iīll most likely end up with a chamber thatīll take way inxs of 100 grains of powder,with ease. Wouldnīt be surprised (going to check) if that chamber of mine will take around the 140 mark or so.
Know all to well that many BP arms of the time were stuffed into the 800s with no ills (like the Remington RB) but where will the use of letīs say 120grains T7 take me long term?
Does ANYONE know?
I don't think a large black powder charge will impose any risk. The Gras (i.e. virtually the same action) was sometimes converted for the 8mm. Lebel. Anyway, the usual experience with black powder above a certain charge limit is that the increase has almost no effect on velocity. It just enables you to achieve the velocity with a heavier bullet. I read this as meaning that the peak pressure is little higher.
What it will do, besides the cost of the stuff, is increase the fouling, and the resulting loss of accuracy if you fire many shots without cleaning. The Chassepot, with its fast twist and deep rifling, is more susceptible to this than most black powder rifles. The spinning bullet experiences the lands like straight ridges, but the non-spinning gases experience them like corrugations.
On a similar note, we hear of the Prussian needle-gun giving extreme problems with heavy fouling. The Chassepot required clearing out of cartridge case debris after a smaller number of shots, but the soldier could that without the water a Prussian would probably require.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Lots got done today. Timney setup is up and running. Not really an especially hard job just cumbersome so in hindsight this i should have done on a bridgport.
Difference in trigger tho is downright laughable.
In turn,the optics. That there with the bolt handle where itīs at certainly sets the limits,but..yeah well...
Ment that i modified the install of the bolt handle beyond what i had in mind but hey..whatever works right.
In turn i turned some more cartridges out of shrink. Amongst those ones out of clear plastics and...i guess it has a place. But TBH...regular black sleeve works just as well as far as iīm concerned.
Now to drill and ream that cone out of the barrel between the sealing cmpt and the chamber..and in turn turning a plug,that also gets reamed to size,to become an elongation of the chamber with an approx 20mm.
One of the things iīve got in mind here with that piston setup is to minimize "leakage area". Ie;i want a piston that comes up close to the "new" chamber end.
How to get away with it?
Added grease for the cartridges...
Guys.
I wanna ask,seing that there "new" cartridge (in short one that fits the chamber diameter) does anyone of you have an idea for a primer holder?
You could probably stack card wad to an appropriate thickness so that you can install a musket cap facing the "proper" direction. I would be inclined to recess the cap a bit to prevent an out-of-battery ignition while closing the bolt (which may be why they flipped the cap in the first place).
Possibly, but I think the main reason is that the partial rigidity of the well-stuffed case is enough for the firing-pin to impact sufficiently on the priming composition without moving it forward instead... well, usually... but not enough for the firing-pin to indent metal as well.
Jesper,
More brain-waves here. . .
Would it be possible to chop the "neck" off your shrink-tube forming mandrel right at the shoulder, then mill a cavity down the center of it at .45???" diameter? That cavity would serve as a holding fixture for a lubed bullet as you heat-shrink the tubing around bullet and mandrel together. You could then insert shims into the base of that cavity to control seating depth. You might need some kind of elaborate alignment fixture extending forward to grip and align the nose of the bullet, but this, coupled with a purpose-cut bullet mold, could go a long way toward getting the bullet straight into the lands. I don't think this concept is "fully baked" in my mind yet, as I see a need to create extra neck for wad spacers and lube cookies. Maybe a two stage operation - assuming this stuff can be heated and shrunk more than once?
Still more brain-wave:
This would create the somewhat weird situation of filling the cartridge from front to back, with the primer assembly being glued in last. The result of this is that the primer assembly wouldn't necessarily need to be flush with the back of the case, but rather be recessed slightly. This would form a "cup" out of the back of the cartridge. A properly designed bolt head could socket into that cup, further assisting with cartridge/bullet alignment.
Even MORE brain-waving:
Assuming that the shrink-tube shell with primer assembly doesn't travel down the bore, the socket/cup fit described above could be exploited by designing the bolt head with "grippy bits" (coned with sharp grooves maybe?) that grab the shrink tube cup tightly enough that it can effectively act as an extractor.
All good,viable ideas in my book.
Yes. A sorts of "bullet centering device" could easily be implemented into the master. No worries what so ever.
On shrink sleeve. The material is referenced for how well it conducts and what not but to OUR purpose the material parts of the specs would be material thickness IN HEATED FORM and shrink bias.
Most shrink sleeve is either 2:1 or 3:1. This means that as long as the shrink sleeve hasnīt for instance shrunk three times its starting diameter you can heat it a zillion times,and itīll still shrink as long as thereīs mechanical possibility for it to do so.
Compare for instance Fredrikīs pic on the opposing page here. You get a solid idea of how that stuff grips the bullet. In summary this stuff hands us a crapload of leeway no doubt. Almost to the point where anything goes,as long as we havenīt "bottomed" the material out.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Primer cup/holder then. Weīve debated this quite a bit.
From what iīve understood the blackpowder caps lack an anvil per what regular caps use. Iow the primer nipple is what forms a blackpowder caps anvil. Sudden stop if you wish.
This brings that if weīre to run a stand alone setup here some sort of anvil has to be provided OR a different (read-smokeless) primer like a 209 shotgun one be used.
The latter MIGHT present an issue to us over here and weīve debated that too..going to make a couple of calls come tomorrow,but for now itīs presented as being under permit as well. Thereīs plenty of us thatīs got permits for varying guns (which in such a scenario is all it takes) but that would be wandering off the main design criteria to us.
Permit exempt.
The Chasse being a sort of caseless ammo proposition it of course in the case of the Chasse comes down to chamber evacuation. It is said,and believed,that this "sweeping" of the chamber is due to the stock rubber disc at the utmost rear of the stock cartridge in conjunction with the gauze used as sort of a fishing net.
Be that as it may or not the evacuation of the chamber is based on a couple of facts of physics being at hand,why those laws at work sure as hell can be used to our advantage in this case too.
What we need to adress is some sort of primer holder,and this primer/primer holder setup needs to fit a few design criteria. First up the leftovers need to be of size small enough to pass through the barrel.
Second up we will most likely benefit from adhering to the stock "sweeper" idea. That NOT said what that sweeper should be made out OF.
In essence these are old guns and we as enthusiast want to shoot them on the one hand and we want to be kind to them on the other.
Steel is the name of the game here why in reality an array worth of materials can be used. Down to soft metals like brass and aluminium.
I bet full soft aluminium would work well even,without marring or in any other manner damage the barrel and its rifling. More so than bronze or copper even.
But.
The main player here iīd say is plastic. Really. Plastic can these days be had in just about any imagineable manner thought of. Whatīs more i bet that IF we arrive on a solution that holds water long term the making of a tool to have such "holders" cast or extruded or whatever it takes..sure is viable too.
The advent of a CAD file would in turn make it real simple to spread across the globe with ease.
IMO thereīs two takes on this really. Or..three if you regard the making of cartridges a little indelicate.
First up is naturally the stock cartridge. Then one thatīs been debated to death just about by now. Weīve all seen the official blueprints for it and i for one can certainly understand those that purse that route. The historical correct route.
With it though comes the ability of the 1860s. Or the limits of it more to the point.
Second up is a thought through modern take on the matter,which to large extent is what we discuss in this thread. The one does NOT rule the other out though,which i at least find imperative to take to heart. Evolution is always a good thing.
Third up...is all the fails. Where people set cartridges off of..dubious performance and safety. This group however is STILL interesting to look into as ideas for No2 can be picked up..
So.
As a sort of reply to your idea of a "bullet holder" Bigslug,yes. It could even be handled as such that you crimp a thinner piece of shrink sleeve onto the base/lower skirt of the bullet and let that tube extend letīs say 10mm (just shy of an inch) lower than the bullet to be filled with grease cookies or whatever you find plausible.
..and to an extent therein lies the side benefit of using shrink sleeve. One thing certainly does not rule another out. Which leaves that the only real culprit left to be settled on is...
What primer and primer holder. Do we even NEED to turn the **** primer around really? Fredrik solves the entire matter by glueing musket caps to a 10mm rubber disc that he in turn glues into his shrink sleeve cartridges. As he fills the cartridge up with BP that musket stays put as the needle comes protruding anyways,and whatīs more the use of the rubber disc in turn minimizes the expansion of blackpowder residue into the action of the rifle.
Iīll draw a fast sketch of what iīve got in mind for my own "balls to the wall" rifle up there. It kind of comes down to the same reasoning as Fredriks,just reusable and serviceable.
Remember,iīm going to replace the stock obturator setup with a stainless piston setup instead. Need to hone that sealing cmpt cylindrical you wonīt believe though...to reamers it is.
Anyways.
That said,time for pics of parts of the Chassepot i presume most have NOT looked into-why they might be of interest. As noted above i plan to have a hammer made out of Alumec,and see that show has been launched..
...and this weeks correct lotto numbers are...:lol:
http://iloapp.elegic.com/data/_galle...00_resized.jpg
...the hammer. Weīve been onto that with the need of a rather specific hammer spring. Well,much of that comes down to the dimensions of that center spindle axle of the hammer right.
Notice that this axle sports first up a rim and in turn a small peg at its one end. The rim is what centers it into the hammer chamber cutout and the small peg fixes it at that bottom.
In short a rather nifty manner in which to guarantee an absolute centered pin,and thus firing needle + holder et al.
However. Also notice the part that is the sear.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
The sear and the small guide are whatīs out of hardened steel. Rest of it is just plain mild steel and done deal.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
...īn here that sear cylinder (thatīs kind of..weird isnīt it? :lol:) is out of the hammer housing too. Please be adviced that the cylinder per se is 11,00mm at its root and widens to almost a full 11,10mm at the top. In other words a sort of wedge,which indeed is felt as you drift the pieces apart.
Doing so sans an acetylen/oxygen torch tho..fugedaboutit. 150 yrs of blackpowder crud makes heat an absolute MUST taking these piece apart.
http://iloapp.elegic.com/data/_galle...00_resized.jpg
Here in turn even the guide has been removed,rendering the only two parts left in there is the roller wheel and its axle out rear-which we wonīt bother with.
So. Upcoming is a lighter hammer to speed up shutter time. All good i guess,and this out of Alumec. A space age material if there ever was one,prompted by ASEA of Uddeholm back in the day.
Think of it as real expensive aluminium of sorts youīve never encountered OR more correctly as a contender to titanium grade 6.
Anodized Alumec normally comes out at HRC approx 65-66.
In other words a material if you sharpen it that can be used as cutters for tools even need be.
The spindle axle though. A steel piece of axle like that can of course always be mimicked leaving us with an axle of better material but less diameter...leaving the door wide open to a MUCH greater selection of springs to be used. Worth it?
Well. I guess that will be part two of this multistage rocket all said and done. The stock hammer housing though weighs its fair share,let that be known.
However.
Having fooled around with a few Chassespot by now let it ALSO be known that it is VERY common for hammers to bind. In one or several places.
This can easily be felt by cocking the hammer and then releasing it slowly under thumb pressure. That movement should in reality be butter sweet..which it often isnīt.
In such a case scenario,find out why and remedy.
Primer holder.
Hm. Fellow local board member Jonas is going to pursue using plastic "beads". You now,out of acrylic that some put together necklaces out of for kids et al. He might be on to something there,calculating that the primer will rupture the bead and thus make the primer reach the main charge no matter...
Ontopic of evacuating the chamber and shrink sleeve in turn.
Knowing a thing or two when it comes to close quarter combustion that part with the shrink sleeve is basically a matter of one thing and one thing ONLY as being able to evacuate the chamber after firing.
Time.
As is we see inxs of 2000degC in the flamefront as an educated guess and that sure is heat enough and energy enough to make said shrink sleeve become REAL small in diameter in a hurry.
Only question is,is it fast enough seing the diameter weīve got at hand NOW. Fredrik reports that his cartridges work real well...and no argument there but then again his isnīt 14,5mm diameter either.
So.
Thatīs the reservation iīve got on the matter.
In turn. If we arrive on a primer holder of weight ample enough it should be the rule of physics act as a broom no doubt,and thereby assist the other parts in evacuating the chamber.
Seems like it would be a simple matter to obtain/construct some sort of nipple/anvil that could be inserted into a percussion cap, which would then be held in place by a simple sheet of paper or foil glued in place on the inside of the cartridge/primer assembly. I'm envisioning a small aluminum tube, if such a thing exists. Once it's got a charge of compressed black in front of it, it would go nowhere. I figure your striker head would need to be somewhat smaller than the diameter of the cap, giving a really hard, indenting bash on the middle 2/3rds or so, forcing contact with whatever you've installed.
Another option would be to fill the cap with some kind of "crunchy stuff" - if flammable, so much the better. . . just so long as it isn't bore-eroding.
You mentioned the LEE 500 above - some of the long range boys here called questions on that one for stability - since I liked the boolit I have been attempting to prove them wrong on it - not able to do that so far - in calm conditions I can get it to shoot but any amount of wind (doesnt take much) and that big pointy boolit goes haywire - seems like for me it gets out to about 400 ok but by 500 its all kaput - a few days back I tried a modification to it by turning a small flat on the front end that seemed to work - just a flat .215 across instead of the pointy nose - something to try if you get that far with this chasse project.