Questions regarding bottleneck black powder loading

[Nowherefound]

Hey guys, so my head is spinning somewhat with all the reading into black powder. I think I get some of the considerations black powder requires vs. loading smokless but I have a few questions regarding starter loads for 8x60r Kropatschek (8mm bottleneck)

1) I've read that you don't do compression with bottlenecks just a drop tube and the bullet seating. This true?

2) Regarding filler. I've used pollyfill for reduced 30-06 for my Garands. I've heard pollyfill is also used to take out the airspace between powder and wads(in 450/577 MH bottleneck cases). How much do you compress the pollyfill? Seems like you would have to pack a fair amount in there to remove airspace. Any feedback on this? Also can you use more pollyfill for testing lighter loads? say 60 grains of FF vs the 71grain FF military load?

3) As far as wads and grease cookies go... this may sound dumb but do ya'll have any fear of seating a bullet too deep and accidentally pushing the wads below the case neck?

4) The bullets I have to load are 175 grains vs the military load of 247 grains... Does bullet weight affect black powder loads the same as smokeless? Is pressure going to drop way down and if so will the black still burn ok with the lighter bullet?

Thanks in advance guys, I know some if this may be simple or I may be over thinking it but it is loading for a 129 year old rifle and I want to make sure all my ducks are lined up and accounted for in a nice little row.

[Ballistics in Scotland]

Some black powder bottlenecked cases, such as the first .303 British loads before the intended smokeless powder became available, were loaded as a compressed pellet, before the case was necked down. But I believe this was never done with the 8x60R. I am a long way from my books at the moment, but I have a copy of Luiz Mardel's "Historia Da Arma de Fogo Portatil", written in Portugal in 1887, and he says it was loaded with "Rothwild" powder (i.e. Rottweil, probably.) Both cartridges and finished cases are listed in the 1904 DWM catalogue, case number 439A, and it stands to reason you were meant to be able to get something into it.

Compression and fillers sound like two problems you are only meant to have one of. There is no danger in compressing black powder into a bottlenecked case, but it may promote inconsistency in performance. A drop tube is one way of increasing the charge, but I would also see what I can do by sticking a shellholder onto something that vibrates, like an electric motor or drill. Wads and a grease cookie were used, but a gas-check bullet, such as the one from NEI I used in my Guedes, would remove any need for this, and give you more powder space. It should be plenty if the powder is good, and about as coarse as you could use in a hand firearm, since the case is quite a bit bigger than the .303.

No smokeless powder, except for black powder substitutes, will come anywhere near filling the case, so with these I used kapok (I think) which is or was available in Rizla cigarette filter tips. It is neatly measured, in lengthwise oriented fibres, and only a few slightly charred short fibres come out of the muzzle. It doesn't do a thing for the airspace, since it is not only a light fibrous material, but every fibre of kapok is a tube. What it does is position the powder adjacent to the primer. I would be very wary of anything very substantial as filler in a bottlenecked case, and certainly nothing granular.

[martinibelgian]

Contrary to what most people claim, there's absolutely no issue in having an airspace in a BP round. I've shot a 1,000+ rounds like that, no issues. Especially handy with large BN cases, because any filler will have to go through the case neck - with the potential to increase pressure, stretch/rupture the case,...
I messed around with the 8x60R albeit in a very different configuration (martini match rifle) - so my advice would be to load it full of Fg black, uncompressed (you compress in order to get more powder in a small case, not to do something 'magical' to the powder), put a card was on top - possibly a grease cookie sandwiched between 2 card wads - seat the bullet and have at it. forget drop filler, tubing, compressing - no need, the case is already quite a bit overbore. This is black, whatever granulation with whatever bullet weight will burn - but a heavier bullet will get more pressure, which means a cleaner burn.

[Nowherefound]

Great info guys. This is the reason I love this board, new to black powder and people are so willing to share knowledge and experience. Now for another dumb question... I keep hearing "fill the case" in reference on how much black to use in this or that. Does that literally mean fill the case up and just seat wad column and bullet over that or does it mean measure how much depth the bullet and wad column take up and fill just at that point?

[w30wcf]

Contrary to what most people claim, there's absolutely no issue in having an airspace in a BP round. I've shot a 1,000+ rounds like that, no issues. Especially handy with large BN cases, because any filler will have to go through the case neck - with the potential to increase pressure, stretch/rupture the case,...
I messed around with the 8x60R albeit in a very different configuration (martini match rifle) - so my advice would be to load it full of Fg black, uncompressed (you compress in order to get more powder in a small case, not to do something 'magical' to the powder), put a card was on top - possibly a grease cookie sandwiched between 2 card wads - seat the bullet and have at it. forget drop filler, tubing, compressing - no need, the case is already quite a bit overbore. This is black, whatever granulation with whatever bullet weight will burn - but a heavier bullet will get more pressure, which means a cleaner burn.

+1 although there is a bit more fouling in my experience.

w30wcf

[Ballistics in Scotland]

Great info guys. This is the reason I love this board, new to black powder and people are so willing to share knowledge and experience. Now for another dumb question... I keep hearing "fill the case" in reference on how much black to use in this or that. Does that literally mean fill the case up and just seat wad column and bullet over that or does it mean measure how much depth the bullet and wad column take up and fill just at that point?



I'm not sure of your meaning, but the commonest practice was to fill the case up to where the rear of the bullet or wads would come, so that the load ended upa uncompressed. There is nothing wrong with that.

The only reasons I can see to compress black powder are when the case is small (e.g. .44-40 in a rifle, perhaps) or when people have made their own black powder by extruding it through a sieve, rather than pressing it for high density. The only reasons I can see to part-fill a case with black powder are economy if it is in short supply, or to minimize noise or recoil, or when the only powder available is finer grained than the rifle requires. I agree that filler over a moderately reduced load is far less important that some people claim. A low-volume filler, such as the cotton wool used in the .577/.450 carbine load, can have no effect on the volumetric ratio. It simply located the powder against the primer end of the case.

One untoward experience with the 8x60R Guedes came when I had some leftover British black powder of the 70s, which was notoriously poor stuff. I loaded a light load of Reloder 7 and did the opposite of the usual duplex load, by filling up the case with black, which had been giving only about 1200 ft./lb with a full case of that alone. It tore off the case-neck, which apparently went down the bore with the bullet.

This is a well documented phenomenon with a hard, gritty substance which doesn't burn. Dr. Mann in 1904 described achieving it with an inert filler of sand, presumably in a barrel ready for discarding. Dry sandbags, surprisingly but no doubt for the same reason, will stop a bullet in a shorter distance than damp ones, presumably because impact locks the grains together, and lubricating water loosens them. Presumably the same thing can happen before the powder is fully alight.