Marty's Arms Molds

[Frozen Run]

Here are the results (Wixey digital calipers):

.749 - 5

.750 - 18

.751 - 2

.752 - 1

.754 - 1



Here is the postmortem:

These are the ones I kept from my initial casting using just visual inspection. I was dropping them onto my leather apron, the one I should have been and will be wearing in the future, and I quickly amassed a mountain of roundball. The problem is lead doesn't cool as fast as I thought it did and a lot of them ended up with dings and dents from sprues dropping on them and other balls. So most of them ended up back in the pot. Also, there were a lot of other learning curves that night which caused failures. Out of the pile I was able to salvage 27 of them. Out of these 27, 3 of them are going back into the pot based on visual inspection during the mic just now and another 2 more are a bit suspect but probably good enough for a smoothbore. I was being very meticulous with the measurements. Other noteworthy points are I am a complete beginner at casting and to put things in perspective your average piece of paper is 4 thousandths of an inch thick, so what variables and errors can be made that can throw your casting off by a by a few thousandths?   

[wattlebuster]

Thanks much frozen run for taking the time to measure them. Ill be ordering very soon

[Frozen Run]

Thanks much frozen run for taking the time to measure them. Ill be ordering very soon

Great! Please post your impressions and results from the mold, I'd love to hear what an experienced caster thinks of it. Don't forget the discount code from my original post.

[RichG]

the temperature of the lead and the mold will change the diameter of your round balls. The amount of shrinkage can make a couple of thousandths difference. ( the larger the ball the more difference). One reason to get a mold to temperature and cast with a rhythm until your done. Depending on the mold it might take a dozen pours or so to get the temp right for that particular mold. Also the little ding and dents wont matter, just make sure the mold is filled out and the balls aren't all wrinkly. Also make sure no lead splatters get on face of mold. That will really throw off the diameter. Also try to keep even pressure holding mold closed.

[Mike from OK]

Give it another attempt... Or 3... Or 4. Your goofups or unsatisfactory results can always go back in the pot.

Once you get the process down pat and develop the muscle memory, you'll get more satisfying results.

Mike

[Frozen Run]

Rich, thank you, that advice will be very helpful moving forward.

Mike, I plan on casting again, I don't really have a choice as my local muzzleloader shop only carries up to .735 roundball. I bought the large lyman ladle the other day, I still need to get a pair of welding gloves, digital scale, and lead thermometer to be all caught up with stuff I learned from this thread.

I took my snaphaunce shooting this last Saturday with the .750 balls I cast. The first shot on target landed in the 10 ring, every one after that was considerably low, I still need to work up a good patch and powder combo for it. It was an eye turner and I let other people shoot it as well and they all landed low at 6 o'clock as well. So needless to say, I spent the day wondering about that 10 ring on the first shot as it was the loosest patch and lowest powder charge I tried all day. When the range got announced cold, my friend waived me over and encouraged me to go take a look at my target with him, I walked down range with him and when we got to the target I poked the solitary 10 ring hole inquisitively and said out loud "that's awfully small for a .750 ball"..."did you shoot my target?" then looking to my friend who was rolling around in the grass, slapping the ground, and laughing like a maniac. I felt guilty for not being upset, if someone tricks you really good then you owe it to them to get a little upset, whether you show it or not. But I wasn't upset. He's been going through a lot recently and seeing him laugh that hard felt really good.   

[smylee grouch]

One thing I have found when casting larger bullets ( like 300 grains+ ) is that if you can,t get the lead into the mold quick you will SOMETIMES get a bad pour with a lot of wrinkles. Hot lead and hot mold help but the hole in the spru plate might be too small also. I have drilled them out a tad to help with that BUT in doing so you cut the EDGE that cuts the spru so I carefully reestablish that edge with a counter sink.

[Frozen Run]

Thank you for the tip. I didn't have any issues filling this mold once everything got up to temp. Also, I am never ever going back to bottom pouring again. I purchased the large lyman ladle and I also purchased one of those old timey cast iron ladles, massive thing, could cast an entire ingot in one pour with it, could probably drop a moose dead in its tracks with that ladle. 

The one thing I am not sure about regarding the mold is the funnel that leads into the cavity has ridges machined into it? I'm not sure what they're for but they are clearly a design feature.

[smylee grouch]

I also have one of those Lyman dippers with the little spout. I found the hole in that little spout too small for my liking when casting large balls si I enlarged that hole too. It helped a lot.

[Frozen Run]

Thank you for the tip smylee, I think I will do the same thing, about what size did you drill the hole out to?

[smylee grouch]

I don't remember the numbers but drilled it out to the point where the thickness of the sides of that little spout wasn't too thin. The lead flowed into the mold much quicker and I had less wrinkled bullets.

[smylee grouch]

Thinking about casting a 750 ball makes me wonder if the Lyman dipper with that little spout is going to be big enuf to hold enuf lead for a ball. A 750 will need 650 grains + or -. 

[Frozen Run]

Hadn't considered that. Visually, the size of the ladle looked like it could cast 1 maybe 2 balls and then I would just incorporate it into a much slower but also much less aggravating casting system. Possibly alternate as some of the chambers start overheating. But checking it online, the capacity of the lyman dipper I purchased is approximately 1.5 ounces which translates into 656.25 grains. Hopefully there was some rounding down in that 1.5 number and I can get one good pour out of it...Worst case scenario, I can just use it with my other molds.

The really large ladle I purchased could easily fill all 4 cavities in one pour, but is not compatible with my current pot (Lee Pro 4-20) so I'd have to get a different pot to use it with. Ideally I can take it down and see if the Lee Big Dipper will work with it?

And the absolute worst case scenario is I can just go back to bottom pouring as that seemed to work fine enough and I'm not selling the snaphaunce.   

[smylee grouch]

If I have it figured right a 75 ball should be about 634 grains so you would have enuf for a puddle on top of the cavity for the shrinkage .

[Frozen Run]

If I have it figured right a 75 ball should be about 634 grains so you would have enuf for a puddle on top of the cavity for the shrinkage .

I hope that you're right, but how did you calculate 634 grains? Here is my calculation:

1 pound = 7000 grains

10 10 gauge roundballs = 1 pound

So 1 10 gauge roundball is 700 grains

10 gauge = .775 inch

.750/.775= 0.96774193548

0.96774193548 x 700 = 677.419354839

So a .750 roundball is a skosh more than 677 grains

Using that same math, a .750 roundball is 1.54838709677 ounces.   

 

[smylee grouch]

I use this formula, .750X.750 X.750 X 1503  Using this a .75 is an 11 gauge which is what you would need to use in a 10 gauge bore.

[Frozen Run]

You're right, when I do the exact same math but use the known value of an 11 gauge roundball (instead of a 10 gauge) a .750 ball is 635.516281322 grains.

7000/11=636.363636364

.750/.751=0.99866844207

636.363636364 x 0.99866844207 = 635.516281322 grains

Essentially 634 grains which in all likelihood is closer to the actual grain size of a .750 roundball than either of the 2 numbers I produced. 

I'm not questioning you, just trying to learn from you. So you took the diameter cubed and multiplied by 1503 grains to get your answer? What is the 1503 number and how did you get it? I'm assuming it is a simplified equation for finding the volume of a sphere in grains but if you could show me how you got to 1503 it would save me from doing a math refresher later on tonight?

The takeaway from my previous calculation, and someone please correct me where I am wrong, is the old rule that gauge refers to the number of lead roundball in one pound is a gross approximation and nowhere near a pound? Otherwise there should not be a difference of 42 grains when calculating this proportionately to two known values?

[Stoner creek]

What is this? Math class?
How does it load? How does it print on paper??? Have you considered that into your equations?

[smylee grouch]

I'm thinking that .775 IS 10 bore but you need an 11 bore ball to fit when you add a patch. The formula is one I got from some old sage about 35-40 years ago . All the paper work figuring will give you some ideas but the shooting will tell the real story. With that large of bore and smooth bore to boot gilt edge accuracy might not happen so perfect round balls with out voids might not be required. With out some lead puddle over the spru hole to draw lead into the cavity as it cools you could get some of those voids.

[Frozen Run]

Wayne, When I took it out for the first time this last Saturday I was shooting low at 6 o'clock, and the group size was about minute of paper plate at 25 yards. I just wanted to get some time in with the gun and I think it'll be a real shooter once I dial in a couple of variables:

The nut behind the butt. This is what everything boils down to. I need to get better, I don't have any experience shooting a musket, and the shooting stance needed given the gun's size and shape is something different to me in a muzzleloader. Black powder as all of you know is a completely different animal from modern shooting, a muzzleloader will take the tiniest mistake or weakness you have and compound it ten times. So having a solid shooting stance is one of many important things to control. I'm accustomed to shooting offhand with a stance similar to a matador if that makes any sense? With a snaphaunce you really need to get on the gun, something similar to this:



The second aspect I will need to dial in and refine is the load. I was shooting .750 roundball with a .02 oxyoke patch lubed with Mr. Flintlocks. The excess was squeezed out between my fingers. The bore was mic at .774 and that ball and patch combo was not producing good compression. One of the balls I loaded even slipped in behind the patch which was frustrating. Fortunately a gentleman there handed me a strip of pillow ticking and that worked better. I think I would have been better with either a .755 or even a .760 ball? I am going to mic the remaining bit of ticking I have left and go down to a fabric store and see if they have cotton ticking or a denim that is slightly thicker. I am also working up a powder load, I'm using 2f and started off with a very light load of 55 grains and worked my way up to 75 grains that day. I'm going to shoot a little more at 75 grains while experimenting with different patching materials until I find something I like that works and then experiment with increasing the grain size. I don't anticipate exceeding 90 grains. I'm also going to try D Taylor Sapergia's recommendation of a .735 ball with a .022 lube soaked denim patch and 86 grains of 2f. Also, I still need to get a digital scale to check for weight consistency and spot voids.

smylee, you are right, 11 bore is .751 and I am casting .750 roundball. 10 bore is the actual bore size and is the size you select for jags and what not. That 1503 number is a handy tip, saves a man a lot of math.


Also, I purchased a pair of welding gloves today. This is just a stock image because it's easier and they all look the same:

       

[smylee grouch]

The denim I use checks out around 23/1000 and I buy it at a fabric store. Pre washed. The denim from the legs on all my old jeans checks out at over 30/1000 so if you have any old sacrificial jeans you could try those. Cut your pre cut patches bigger. 

[drago]

How do you know how many cavities are in each size?

[alacran]

My friend, you are shooting a smoothbore musket with a snaphaunce lock. Shooting any kind of smoothbore is more art than science.
How you mentally evaluate your sight picture will change from day to day. Once you find a powder load and patch combo that doesn't burn through your patch and doesn't fowl up the barrel, quit fussing with it.
Take that load and shoot a couple hundred rounds through your gun and see what you learn.
this is especially true if you gun does not have a rear sight. Since it is a snaphaunce, I assume it doesn't.

[Frozen Run]

drago, you can go to the website and select the mold you want and then count the number of cavities in the picture that pops up.

alacran, you are correct, it does not have a rear sight. I appreciate the advice and will take it to heart.