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adamsutherland
OK seeing as how I’m on a muzzle loading roll along with the Gardener bullet I also like a good mould of the original Enfield Pritchett bullet.
This drawing was done for/by Oyvind Flatnes when he had a Lee special order mould cut for the Modern Pritchett he designed, I have one of these no longer available moulds and the short bullet works well in the slow twist P53s especially at the shorter ranges.
I would like to see a mould of each the long original and the newer modern Pritchett.
Any one else shoot 577 rifled musket, Britain supplied a substantial amount of these rifle to the North and the South during the American Civil War so surely there has to be some of you shooting these fine firearms.
adamsutherland-
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Tom Myers
Thank you very much Tom, it is looking good.
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The diameter of the 0568″ needs reducing to 0.566″ to accommodate the slightly thicker paper we get today.****************
Also how would the small base cavity look using the rounded shape but same volume method as has been dome with the large cavity plug?
I worked on those drawings yesterday while I was quite tired and not really thinking straight.
For a hollow base, pointed nose slug to be formed, it would probably need to be swagged.
In order to cast these hollow base bullets, the molds, quite obviously would need to be constructed as a Nose-Pour molds.
So the Original version mold drawing will need to be modified with the nose ending in a small flat meplate as is the Modern version.
I have adjusted the drawings to maintain the weight and reflect the changes in diameter and nose meplates. Any changes to the drawing images will simply replace the posted drawingsWN (multiple version images can quite rapidly become quite confusing)
I am not familiar with the size, style or volume of the shallow base plug to which you refer but, if the cavity were to be of the same volume, the base of the cavity dome would need to be wider in proportion to the decrease in length of the sides of the tapered cavity. If you could point me to an image of the shalow cavity, I could calculate the shortest length that would still maintain the volume with a slight taper to the sides to accomodate and easy release-ejection of the bullet from the mold
Thanks Tom.
Here are the dimensions that I sent Al.
Hope that this helps.
Hi Al
Going with the drawings in the Discussion Thread.
Looking at two mould diameters, 0.550″ and 0.564″ I would now like this diameter to be 0.566″ .
Measurements: adjustable for length from the longest at 1.100″ to 0.900″ if your blocks can accommodate this.
I would also like two base plugs per mould diameter. One as per the drawing at 0.435″ deep and a shallower one at 0.210″. Plug width at base 0.424″ for the 0.566″ diameter bullet and 0.410″ for the 0.550″ diameter bullet. Plug diameter at top of the deepest plug 0.310″, same taper for shallower plug with correspondingly lager top diameter.
Height of ogive 0.485″.
Diameters based on soft lead flashing, plumbing pipe, hardest being 30 to one lead to tin.
Obviously the point on the original Pritchett will disappear on a nose pour mould so the nose will be more like the modern Pritchett as determined by your pour hole diameter.
Hope that this helps.
Best regards
Adam
Adam
For your consideration.
I re-worked the drawings to gain a compromise with your specifications and the limitations of a nose pour using the approximate diameter of Al’s sprue hole diameters and a constant 0.700″ tangential ogive radius on each design.
The specs for a short base plug with a depth of 0.210″ while keeping the same volume simply is not to be. A depth of .310″ would be about the shortest length that would maintain slightly sloping sides and still have the same volume. I would hesitate to use a hollow-base pin with that depth and volume as it would probably cause severe release problems.
A depth of 0.21″ will essentially be a hemisphere with a diameter of 0.42″ with approximately 1/2 the volume of the 0.41″ depth and should not cause any release problems at all.Al indicates that he can work with the designs as drawn so I am posting 4 images that show the design changes and the variations in the hollow bases in the 0.566″ and 0.550″ diameter versions of the designs.
Look over the sketches and see if they meet your requirements. If not, we can work on them some more.
The images in my original posting will also be replaced to avoid confusion as to what is being considered.
Respectfully,
Tom Myers
Precision Ballistics and Records
Thanks Tom Looks like we are getting there.
I have a question about the base plugs, the rounded pattern as per the drawings is because of a limitation in the soft ware not the mould manufacturing process?
If that is case then could Al still make the deep base plug with the flat top?
The shallow base plug is fine rounded as shown in the drawing.
Thanks Tom Looks like we are getting there.
I have a question about the base plugs, the rounded pattern as per the drawings is because of a limitation in the soft ware not the mould manufacturing process?
If that is case then could Al still make the deep base plug with the flat top?
The shallow base plug is fine rounded as shown in the drawing.
Adam,
Proceeding on the assumption that Al CAN make the hollow base plugs with a flat top, I manually sketched the flat top hollow base dimensions into the existing sketches that the Bullet Design software produced.
The dimensions in the 0.550 versions are the same as the original Enfield Pritchett sketch and the dimensions of the 0.566 version are modified to maintain the same skirt thickness and volume as the 0.550 version.
The volumes and weights are slightly different from my original drawings. In order to be as close to the drawings of the actual bullets as possible, I got really, really, picky with the image scaling procedure and came up with some more accurate dimensions for the original hollow base design.
You can decide if you specify the short or long or domed or flat top or all punches for each mold.
I will also add these sketches to my original post
Respectfully,
Tom Myers
Precision Cast Bullet Design Software
Scotsman13a
Thank you for taking the trouble to do that Tom.
The previously unplugged shallow cavity larger Pritchetts had a the rounded cavity, but they went with the flat topped deep cavity in the 0.550 diameter version that would take a clay, or boxwood, plug that sat slightly proud of the base and was driven forward into the cavity upon firing to expand the skirt to grip the rifling so the cavity was flat topped to take the plug when driven forward. As I am using primary sources I am trying to stick as close in the workings of the bullet to those as possible because we know they worked and worked well.
I think we are now at the stage when Al can put this up as GB for sign up.
Thanks again Tom for your efforts in helping us here.
robertmcbride
garyaardahl
Greetings the Forum!
I was searching online for possible sources for Pritchett Bullets or molds and lucked onto this discussion. I’ve registered as a user and would like to add my name to a list for a .550 long (original) mold. I’ll look for the Group Buy opening. Will a notice go out or do I need to check in? Thanks so much to all so far for this great discussion and project!
Cheers,
GarretSwedeNelson
I initially asked for an adjustable for length mould but my experience with my adjustable for length Brooks Pritchett mould having cast and shot over 500 bullets with it so far I find myself either making short or long bullets and not finding a need for small length adjustments in between so an RG mould would be fine with a selection of long and short for bullet length along with deep and shallow, domed and flat pins.
A four cavity Pritchett mould!
Phwoarrrrrrrrrrrrrrrrrrrrrrr!
I’ll end up having arms like Popeye.
Any thoughts about a clay plug mould to go with this Al?
Tom Myers
Scotsman13a
robertmcbride
garyaardahl
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