the BP cartridge PPB bore rider

[rfd]

In a dead nuts 0.450" bore, I would consider 0.450- to be too loose. 0.449, definitely too loose. 0.451" is probably too tight and will wear out your thumb in a match.

The only really good way to measure the thickness of paper with normal measuring tools is to measure a bullet or drill bit shank with calipers or micrometer then wrap it with two wraps of paper and measure it again, just like you did before. Subtract the two diameters and divide by 4.

Measuring single sheets with calipers or normal micrometers is problematic in my opinion.

relating to brent's above post, i'd like to start a discussion of just what it takes to make an accurate PPB for a given rifle, and how to go about creating it. getting the *right* diameter PPB (meaning the paper wrapped slick) is probably the most intimidating part of loading accurate PPB bore rider, black powder loaded cartridges.

i'm hoping some of you most knowledgeable PPB aficionados would please weigh in.

[ian45662]

This weekend I will for the first time be shooting my cpa at a silhouette match. My friend made the barrel and best we can tell after lapping the bore is .4505 or so. That’s at the breach. It does have a slight choke so it will be a little tighter than that at the muzzle. My bullets are maybe between .450 and .4505 and they are looser than what they are in my green mountain barrel but not much. Just barley noticeable. All I have been able to do to this point is fire form cases and don’t have any real good indication on how it’s going to preform but we will know something this weekend. Anywho best I can tell my GM barrel is .450 BUT..... having said that I have never stuck a pin gauge in here to see what it actually is. At this point I am just going by feel.


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[rfd]

so ian, yer patching right to bore diameter for a bore rider PPB?

what's yer slick diameter prior to patching?

what paper are you using for patching?

and how do the PPBs enter the rifling - easy or not so easy?

[rfd]

another general PPB bore rider question ...

is there a direct relationship between the PPB diameter and the alloy hardness of the slick, in terms of upset/obturation?

[ian45662]

They are .445ish before the patching. I am using the Seth Cole 55w paper. They chamber pretty easy. They are snug but not so loose that they will fall through the bore. Not so tight ya can’t push them from bow to stern with a cleaning rod.


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[Lead pot]

Rob, It makes a difference with the paper I use on how tight I patch my bullets to bore.
I mostly use the old Southworth cockle finish 100% cotton onion skin paper it compresses some when pressure is applied to it's surface so I patch one thousand over bore using it. The common paper like the paper mill is a wood fiber with a lot of sizing in it that makes harder than the 100% cotton so I patch it at bore diameter so I can load it without having to use a cartridge seater if I can't close the breach.
What I see down range and over a chronograph when excess force is used seating a round is the ES gets larger and groups open up. I think what causes this is it's changing the compression especially with slightly compressed powder or using a lube wad. A lube wad especially if the lube gets soft it gets squeezed past the bullet and maybe under the patch where it is rolled under the bullet base and the patch gets carried down range farther. I don't know for sure if this is going on or not but I saw patches farther down range and even paper on the target backer at times.
I feel that when the extra pressure on the bullet when seating it compresses the powder and it changes the chamber pressure opening the vertical.....just a thought on my end. I don't like to use two thumbs to seat a round to get the breach closed.
As far as the direction of wrapping the bullet I see no difference. I have to ask....how can a patch unwrap when it fits so tight in the bore when the powder is lit. Will it release from the bullet faster as it clears the muzzle? I don't know. But I never have seen any difference when I shot both ways side by side.

Kurt

[country gent]

I run a .443 dia slick from a brooks adjustable cup base mould. I use the Seth Cole 55w paper and end up around .449 dia wrapped bullets are cast from 20-1 so pretty soft. ( I recovered some from the sand backstop at the club and they had expanded to almost 1" in dia and about 1/8" of base still showed. Weighed 496 grns from original 510). I dry wrap on a patch board, its easier for me. I patch so when the fold over s doe there is a small center of the base showing thru. Maybe .093 circle of lead or so. this makes for a very flat base and easier to handle. Also saves clipping tails.
Paper can make a big difference in the bullet even if the same thickness di to grain, sizing coatings, composition and other things. How you wrap makes a difference. wet, damp, dry, by hand on a board, tension used and maintained can and will stretch paper making it thinner and affecting overlaps. Stress in the paper also can have an affect here, Set a patch on a damp sponge and watch it curl up and then un curl and lay flat.

While I don't think the angles make a super big difference getting the length right so the overlap is smooth and even is. 2 wraps with about .030 gap between ends works for me this gap is while under tension of wrapping. Not only cant the ends meet or overlap but when the second wrap forms over the edge it leaves a small radius angled spot that if not taken into account will leave a raised spot. I normally run 45* ends but have experimented with 30* and 60*. Depending on how you wrap your templates will be slightly different, wet and damp will be wider and shorter die to stretch narrowing and lengthening the paper dry will be a bout the right width and length, a little shorter for stretch.

One of the issues loading the bore rider is most dies don't size down to the neck size for the hand seated .449-.450 dia bullet. I use a bushing die for this and can adjust bushing sizes to just what I need.
Recovered patches can tell you a lot about load and how the paper is performing. In my 45s I normally get confetti from the outer wrap and the inner is recovered with the fold over intact showing rifling marks. They are recovered 2-5 feet from the muzzle. MY 40 - 65 with douglas barrel both wraps are confetti at the muzzle the fold over is recovered. I suspect part of this is the diuglas barrels rifling is a little shallower being button rifling. Or maybe a little sharper edges. But loads are accurate.

[texasloader]

After reading several threads I decide to put it to you guys. I'm new here, so I have to ask stupid questions. Why paper patch at all? can't we just up size the projectile with soft lead for loading? I know it wouldn't be historically accurate for the cartridges but why not?

[rfd]

After reading several threads I decide to put it to you guys. I'm new here, so I have to ask stupid questions. Why paper patch at all? can't we just up size the projectile with soft lead for loading? I know it wouldn't be historically accurate for the cartridges but why not?

dunno what ya mean by "can't we just up size the projectile with soft lead for loading?", but i paper patch because there are no leading issues, there is no OAL issue with a bore rider PPB, building these cartridges is too darned easy, i like the historical aspect of doing it the way it was done, and .... when done well, PPB loads are very accurate.

[Gunlaker]

After reading several threads I decide to put it to you guys. I'm new here, so I have to ask stupid questions. Why paper patch at all? can't we just up size the projectile with soft lead for loading? I know it wouldn't be historically accurate for the cartridges but why not?

Just for the pleasure of it . It's fun shooting these old single shots either way, but there is something special about shooting a Sharps rifle with paper patched bullets.

Chris.

[ian45662]

For me they shoot better than greasers.


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