Yet another Kropatschek, need advice

[Racing]

As some of you have surely seen i ended up with a rather decent Kropatschek in my lap, one in 8*60 (or 8*56 if you so wish)





The thing sure looks the part, and rest assured.. rest of it is too.
Now.



This is one of them old ´uns that require you reshape brass, and as many before me i opted to go with 348Win as a parent casing.
Anneal to just below the waist line, and thus the reshape on both 8mm Lebel die and the proper 8*60 Kropa by RCBS is smooth as silk.

After reforming i opted to fire form the approx 100pcs of Win brass i got a hold of, and that also worked a million bux. No issues what so ever.

We cut our own molds, just with this rifle we haven´t had the time to arrive on doing it just yet so as i´m lazy i read up and ordered the LEE mold on 205 grains used by many, and this is where my troubles start.



Cast like 50+ up in a "semi stiff" alloy, no worries. However. This boolit is intended for a gas check, which as i regard it should really be an option as to use or not - per always.
What happens here though is that at 200 grains.. what i get to crimp the boolit in place and keep with referenced COAL is a case that ends up just shy of the lowest driveband.
Sure.
I guess i could crimp that on there, but it sure isn´t correct.

What gives?
I guess those of you down this path before me has some sort of solution to this? Even if i opt to put a gas check on there, it´ll just be "brick on brick" in such a case scenario, which sure isn´t optimal either.

COAL in this case is said to be 81-82mm.

[Bloodman14]

Just a compliment here, as I know nothing about these; that is a good looking rifle.

[pworley1]

My loaded rounds look about like that. I did use a gas check and beveled the rim to match the bolt face. They feed and shoot with no issues.

[Racing]

Just a compliment here, as I know nothing about these; that is a good looking rifle.

Thank you.
Yes, spent a little time digging for a decent one and found this one down in France.
Not "cheap" but i guess..condition it's in tells the story.
Made in 1886 but is a revised model for "colonial work" and thus carries the upgrades for using smokeless - to push a 250 grain pill beyond 2300fps.
In my case tho it's duplex loads that are on the agenda.

[Racing]

At the shop right now, taking a more in depth look at this.
Got the dies for 8mm Lebel and 8*60 Kropatschek both and both of them sports expanders that hand me a inner diameter of approx 8.10mm and IMO that's simply to small as I aim using 8.35mm boolits down the road. As this is a machine shop turning a new expander on the lathe is the least of my problems but i presume that would bring that i should turn the neck thickness down a tad too to make that work?
Idea here is one of lead only, gas check or not, why I reason as such that the tighter the fit vs the bore the better.
Have slugged the thing and it comes to 0.329".
Feels a bit peculiar but I guess..If that's what needs to be done it is what it is?

[Racing]

Right.

Added material to the expander of the LEE die making it 0,327" and at that to produce a slight flare. This seems to have been what the Dr ordered, and indeed the boolits now entered the brass as intended.

In doing so though i tried to chamber the rounds, as duds, and that was in short a no-go. Upon closing the bolt i literally forced the main body of the boolits into the rifling.
Which stands to reason as the bore diameter is to come in at around 0,305" and the major diameter of the body of the boolits produced from the LEE mold hands me 0,310"+

In short this means that with the LEE offerings the COAL set can´t be used (81-82mm total). That simple. When we regard the original drawings for the cartridge in case it shows us exactly that, and that the original lead boolit used was a paper patched slider.
Hm.
This is where it falls apart a little to me, so plz hear me out.

I´m no stranger to PP. Not at all, use it on a regular basis for my various blackpowder rifles and.. let me put it this way, there´s like three cabs here around the house and they´re filled to the brim.
In my experience PP sliders and to a VERY large extent old paper cartridge guns benefit from the use of bore-riders, and this greatly when we´re talking accuracy.
No matter if a Starr carbine or a Monkey Tail rifle or a Chassepot.. same same..

What i´m saying is that there´s principles involved when it comes to paper patching, such that we are all aware of.

For a gun like the Kropatschek, as the general idea here is to look into what´s to be had from an accuracy point of view, that brings that a PP slider in my book need to adhere to the same basic principles as does the rifles just mentioned.
No issues.

Enter the fact that the Kropatschek is a brass cartridge gun as that within reason sets limits as far as dimensions.

So. I modified the expander of the LEE set by brazing. Thinking as such that if it all goes to hell in a handbasket i can always just get rid of the brass involved and revive the thing back to stock. This is for trials after all.
So. I set it to a major diameter of 0,327" on the lathe and went at it. Sure enough, adding a small flare to it made the LEE boolits enter like on butter, and at that expand the neck slightly upon install... All good.
Crimped them in place ever so slightly using the grease groove between drive band 2 and 3 and.. there was sure room enough for the neck of the cartridge, no matter the now increased diameter upon chambering.

But. With a set COAL of 81-82mm with the LEE boolit (all drive bands showing as per the pic above) that made me end up with literally slamming the bolt to a close and upon opening the bolt again the net result that came out was no doubt with a bullet carrying the proof of rifling being engraved into it.
In short using the LEE boolit in THIS rifle will entail settling for a shorter COAL, and seeing blackpowder being involved this IME is not an issue (as it might very well be using smokeless).

With the fire formed brass pouring 40 grains of T7 down there, by weight, down there followed by 7 grains of Norma 200 leaves AMPLE room, and that to spare even.
As this was fire formed i "solved" this by simply adding a 38cal wad in shoved down the throat of the cartridges to come to a rest on the powder charge and done deal.

Using a boolit though, a different matter all together. I presume that the same load (or just replace the T7 with 55 grains of BP) will work just fine seeing the original load for these rifles when blackpowder.

I want to stress that the use of a duplex load is NOT about altering performance but about keeping the rifle running seeing what a duplex load hands as far as lack of fouling.
By far not an exact science but.. 7 grains of Norma 200 i equate to approx 20 grains of blackpowder in MY application. Thus 55 grains of holy black and 2o grains atop that, well u do the math - which puts us close enough to the original BP load.

In turn as the mainstay of the charge IS blackpowder i see no real issues involved with making the cartridge slightly shorter from a burn/pressure tech point of view.
It might very well be from a feed point of view though, different matter all together.

Those of you shooting Guedes and Kropatschek rifles, please voice up! I presume and bet that you´ve been running into question marks on this as have i?

Mark that upcoming is a slider of own manufacture. This slider will be.. longer, as we´ll strive for a 250 grain total - which i presume will make the entity of my reasoning above moot.
But.
Now it´s about making this LEE boolit work, and as i regard it there a bit to figure out here.?
U tell me.

[huntj3]

Unless you’re absolutely set on historically accurate OAL, I remember my kropatschek having a cartridge interrupter/holder to keep the rims in place. If my memory serves, I just seated the boolit a little deeper to the next band.

My chamber cast shows my groove diameter is .331” with about a .338” throat. This made my buffalo arms 50-110 conversion brass too thick requiring significant neck turning until I got a reamer. I made 348 win conversions too but primer shortage stopped me. I won’t be able to experiment further due to a recent move as well.

Keep us posted!

[Racing]

Thx guys.

Middle of the night over here, and this kept me awake enough to look a little deeper... (yeah that and a glass of single or two LOL)

Me i´m used to doing calculus so.. stepped up and took a look at Greenhill as well as Miller.. that sure didn´t turn me any more happy cause seeing the twist rate of this rifle (1 turn in 11") that brings that we ideally will need a boolit that´s 1,4-1,5 inches long (in round numbers to us metric folk that translates to 35,5 to 38mm approx).
That´s one tall *ss piece of kit, right there!

The LEE in case is a rather far cry from that. A REALLY far cry actually. The LEE comes in like 10mm short of that, and the difference in length isn´t what gets me...

Difference in weight is. Haven´t crunched the No yet but.. an added 10mm will sure make them 200 grains of the LEE jump. I guess that brings a sorts of "back to base" in as much that a slider will be of lesser diameter and thus lower total weight while still fill the numbers needed. Or.. what comes up on the computer anyways.
No matter, the issue here is that ONE of the stock original offerings was exactly that. A paper patched bore rider. Go figure.

What´s more making this happen, as is noted above, brings that we´ll HAVE TO make it a bore rider. Simply ain´t room enough for anything else if we still want to be able to stuff powder in there.

Don´t get me wrong, couldn´t care less as we cut our own molds (ya gotta love CAD! LOL) but.. we need to arrive on a reasonable design n numbers here.

Could i ask those of you so inclined to look a Greenhill formula calculator up online or the likes and double check this? Please.

Say 36mm. That´s on par with a 45cal boolit for a 451 rifle, easy at that.

Keep with me here lads. What i´m thinking is thus a slider. In other words a paper patch, and this slider to be of say 36mm total length and that at a diameter of 8,05mm.
We´ll most likely need an at least semi sturdy pill, so let´s assume we´ll arrive on the BHN 10-15 mark somewhere. Alloy in case will tell that for an 8mm boolit we´ll need to "compensate" like 6-7/100mm for shrinking out of the mold?
Along those lines?
That equates to 8,05+0,07 = 8,12mm diameter.. and this for the actual pill. Then we need to figure out the depth of the paper patch as parts of the boolit will be a bore rider.
Hm.
That also brings that the paper patch set depth will acccount for boolit free flight to an extent (thinking absolute pressures here).

Right.
Or am i?

[Racing]

To dwell on this a little further.



That there is a drawing of one of the stock offerings for this thing by the Portuguese, and there´s a few different things to note.
First up not even them arrived on a boolit of 36mm while sure as F though way longer than the LEE offering.
Mark the use of a grease cookie and the slight concave to the boolit base. Ditto, it seems this was used with 2F powder, which most likely would be equivalent to Swiss with todays offerings.

That said, not even 32mm will ante up vs what Miller and Greenhill tells and what´s more if we´re to keep within them 82mm COAL that brings that a 36mm boolit will leave no room what so ever for a grease pill.
..which is where duplex enters. So all good i guess.



In turn if this drawing is of the stocker we can arrive on that we paper patch a wee bit different these days. If we put forth a mold that´ll hand us an 8,05mm boolit and add to that a paper patch from 0,06mm paper that equals a diameter of 8,29mm.
Paper being pliable after all, i guess we just solved first up any and all issues with leading really, using duplex the issue of fouling and in turn using paper patch how to fill the grooves?

U tell me.

[Racing]

Hm.
Tonight was blackpowder night at the club so i had loaded a No of rounds up, duplex.
In short that LEE ca 200 grain pill and then 40 grains, weighed, of Triple 7 and in turn 7 grains of Norma 200. If we reason as such that those 40 grains of T7 is about 55 grains of black, just a tad hotter, and then have a multiply factor of 2,8 on the Norma 200 that basically brings that the cartridges were of approx 75 grains of black - give or take.

Rifle was a true blast! Only shot steel tonight, semi small gong, at 100 meters and never having shot the thing before i had fellow club members spot for me.. was on target in a heartbeat.

Right. So bore slugged to 329" groove diameter and them LEE pills sized to that. Charge held in place first up by a 38cal dry wad, and that was followed by a 32 cal greased wad - riding the actual neck of the cartridge.

Recoil was semi light, have to say, and the gong just kept ringing. Like 25 rounds or so total.
However.. spooky deal cause i was like 10 rounds in when i had one that simply sounded different. Turns out, case separation. Yep. That in essence virgin Winchester piece of 348Win separated just below the bottle neck and what´s more the reminder followed the boolit out
Nope. No signs of over pressure what so ever, just a fluke separation. We had both range rods and decent flashlights around though, so checking the chamber for remnants was done in a heartbeat.
Had us puzzled the lot of us as you can gather. Looking down that chamber though i feel i´m going to hand it a good polish. Rough? Nope, not really but.. just want to make sure.

Anyways.
We´re all still here, limbs intact so no harm no foul.