8 millimeters

Well gents, i´ve gone and bought me an old Kropatschek which is one of the "later" ones intended for colonial use.
Hence it thus "runs both ways", BP and smokeless both.

That said BP is where it´s at to me, and i guess this is where this post takes off cause i want to dwell on what could be done as far as a slick/slider.

Have measured bore to .330" inches.

https://i.postimg.cc/pLW2MtvJ/19.jpg

https://i.postimg.cc/j5s6z2YJ/30.jpg

For those not in the loop, absolutely lovely rifle.
Now. Know i´ve read it somewhere but can´t for the life of me recollect - twist rate of it. Recall it being "modern" though and taking the smaller caliber into account. 1:10 or there abouts.

https://i.postimg.cc/SR49Mkz9/45.jpg

Brass i make myself from 348Win parent casings, very easy to perform. Use a three stage setup and anneal brass beforehand. Dies used is for starters the LEE 8mm Lebel, followed by RCBS "reform dies" and in turn RCBS FL loading die set.
Then fireform before going any further. (Ie shooting blanks)

https://i.postimg.cc/sDyDzTK2/41.jpg

The original cartridge was either patched or very early jacketed. Ie; very soft jacket, be that as it may.. PP.

https://i.postimg.cc/tgbzNQzj/44.jpg

For reference.

I shoot PP 45´s and have at least reasonable success doing so. On this though i don´t even know where to start TBH.

Point here being that over here in Europe at the time many a rifle was handed boolits of lesser diameter than rifling dia and was expected to bump, to a reasonable degree.

That´s however not how we do it PP today? In essence most used are setup as bore-riders to my knowledge, and this can certainly be handled in this case too.

One of the aspects to take into consideration here as i regard it being rifling depth, which is excessive by todays standards albeit still not on the same level as the very early bolt actions like the Mauser -71, the Chassepot Mle 1866 or Gras Mle 1874.
Ditto on that one, sry to say. Got the numbers on a note at the shop.. and write this on my laptop at home.

Regardless.
Paper i normally use is 6/100 of a millimeter thick uncompressed. Ie; approx 2,5 tenths total on diameter IOW.

FWIW we CNC cut all our own molds why as far as design the sky´s the limit really, while it being a slick.. nose ogive mainly i guess?
Boolit weight we´ll try and keep around the stock approx 250 grains. Ie; a rather "tall" boolit all things considered.

Have taken a look at what´s out there but can´t really say i grew all that much wiser from it.

Any ideas as where to start apart from the downright obvious? Bore rider in this case too, and let the paper handle obturation?

Any qualified ideas on the matter would be REALLY appreciated gents.

Btw.
Not that it´ll affect the actual slicks design all that, but i plan to mainly use this thing duplex. Then with a 10-15% Norma 200.
Mainly as i´m a lazy eff... LOL
It sure helps as far as needing to clean the thing out like a mad man between shots.

Then of course go all BP when comps.

I would measure the throat and the ID of a fired case and use that to guide you as to what the patched diameter needs to be. The less you can make it bump up the better it will shoot. And if it is about the same length and shape as the original bullet all the better so you can make it feed. That is a beautiful rifle by the way, and quite rare in the US. I have never seen one in person.

https://i.postimg.cc/pXnj5z56/35.jpg

Thank you. Looked around a bit before deciding on this one and am happy with what came out the other end.
Albeit metal n furniture was in very good working order with the mainstay of the blueing intact the wood was rather dinged up and in turn miscolored.

https://i.postimg.cc/HsGw26mg/37.jpg

Steamed the majority of the dings out and in turn cleaned the wood with a local, to us, oven cleaner followed by the use of oxalic acid.
In the pics, just a first layer of linseed. It has darkened considerably since then.

https://i.postimg.cc/gJSh8KKf/33.jpg

What preceeded the Kropatschek from an ammo POW was the Guedes while for a repeater the 8mm Kropa was certainly new at the time. This specimen is what´s known as a colonial gun, rendering that it´s seen upgrades on a number of points. Sights included, which are marked to a very optimistic 2200 meters.

https://i.postimg.cc/9XkTfJ09/34.jpg

So for those not in the loop this is a tube mag gun. There´s a brass tube beneath the barrel that takes 8 of these rounds - running in essence the entire length of the barrel. In turn one on the lifter and one in the chamber for a total of 10 need be.
Rather hefty rifle seeing all of that.
Quality of the build though, especially so seeing the age, is downright mind blowing. Smooth as silk - as the saying goes.

Thx on the pointers, and i guess i´ll take it from there.
As noted we CNC cut our own molds and as this will mainly be a blackpowder endeavour i want to stay true to the original weight of the boolit at least, of just shy of 250 grains. I guess we´ll end up there with a slick too, seeing the lack of GG and what not although that boolit will be of slightly lesser diameter.

the FIT & FINISH back then is absolutely the finest machining ever!!

Thank you for the additional post. That is certainly a rifle worth having. Good luck making ammo for it, that shouldn't be a problem with the tools you have available.

I used a 255 grain bullet, thought it was original. 323 with 2 wraps of .002 paper. Don’t compress. I easily blew the shoulder off a couple times. Yeah, this way the paper will seal it. Should have used a grease cookie.