Tanner RB mold question:

[mhb]

I have been thinking of ordering a Tanner mold and have been in contact with Tanner about my requirement: I want a mold to produce a finished RB at .625" diameter. Tanner will make any desired diameter mold, but will not or cannot guarantee to provide a mold to produce a pure lead ball of that diameter or any other: rather, he will make the mold cavity to the customer's specified diameter.
I am aware of the factors which contribute to the difference between the mold cavity diameter and the finished cast ball, and even with the known shrinkage factor for pure lead and heat expansion factor for the mold material, cannot with any confidence specify a diameter for a custom mold cavity.
I'm sure there are those here who have experience with Tanner's molds, so am asking for input on the nominal diameter of his molds versus the as-cast (and cooled) ball produced. Any help appreciated!

mhb - MIke

 

[TFoley]

I have three of Jeff Tanner's moulds and I've been very happy with their resultant products for many years. I don't have anything as large as you need, but the .451 and .440 balls they cast are so near their declared diameters, after a few have been put through, that it's a never-no-mind.

BTW, Jeff Tanner died back in January this year, but the company he founded continues.

 

[mhb]

I have three of Jeff Tanner's moulds and I've been very happy with their resultant products for many years. I don't have anything as large as you need, but the .451 and .440 balls they cast are so near their declared diameters, after a few have been put through, that it's a never-no-mind.

BTW, Jeff Tanner died back in January this year, but the company he founded continues.

Thanks, Tac.

My correspondent at Tanner's is James. I explained my need to him and he said that, due to unhappy customers in the recent past, they would no longer guarantee a specific ball diameter, but would make any desired cavity as specified to the thousandth of an inch. His best recommendation was to order a .628" mold and expect it to produce a ball within a few thousandths of my desired diameter of .625". But, because a friend is among those unhappy customers, I'd like to know more about mold cavity diameter vs. bullet diameter as produced by Tanner. And, I admit to being somewhat surprised that a mold maker of good reputation and some years' experience is not able to better control the technical issues associated with his mold material and the pure lead to be cast to be able to better assist the customer in getting a custom mold meeting his requirement.

mhb - MIke

 

[hanshi]

Years ago I ordered a Tanner mold and specified a .590" cavity. When I got the mold I never measured the resulting lead ball. Then one day I decided to go ahead and measure some ball. I used soft lead this time that was not quite "dead soft". The measurements came out to, ready for this, .590". My casting experience tells me that ball from this mold will always be within a thousandth or two of .590" depending on the quality of the lead. Can't beat that!

 

[fleener]

I had Tanner make me a mold last year in the .730 range. I dont remember what I ordered, but I ordered a mold that would put me in the range I wanted to be, and I could go either up or down with patch thickness to get the round I wanted. I ordered mold and patches from them. The combo turned out perfect for what I needed.

One or two thousands is not much.

Fleener

 

[Rifleman1776]

mhb, your expectations are unrealistic. He is promising accuracy in mold size. Can't ask for better than that. He has no control over what kind of lead, or other material, will be used in them. Methinks it is up to you to determine shrinkage, or expansion, from whatever material you will be casting.FWIW, I cast a bunch of balls from almost pure zinc with a Tanner .590" mould. They measure .592" to .594" diameter.

 

[mhb]

Hanshi, Fleener and Rifleman:

Thanks for your responses.

Fleener: it would be VERY helpful if you could tell me exactly what diameter mold you ordered, and what diameter ball it produces in pure lead. I can vary patch thickness, but have determined the size ball I want, and would prefer to have that.
Hanshi: I've had good experiences with various molds, in iron and aluminum, and usually the nominal mold diameter produces a ball or bullet very close to that size, but have also noticed that the actual diameter of the cavity will vary a few thousandths from the nominal, depending on the maker and the material: e.g.; my Lyman mold for .600" RB actually has a cavity of .603", and produces a pure lead ball of almost exactly .600". Pure lead shrinks when cooling, while some alloys actually increase in diameter. My experience leads me to believe that major mold manufacturers know how to compensate for shrinkage (or otherwise) of the bullet alloy, and for heat expansion of the mold material.
Rifleman: My only expectation was that someone here could tell me about his results with Tanner RB molds and pure lead. I know the shrinkage factor for pure lead, and told Tanner that's what I intend to use - they can find that, too, if they don't already know it. They have considerable experience with their mold material (CZ121 brass), and the expansion factor for that is available: I do not think it unrealistic to ask a manufacturer of custom molds about the performance of the product. As they were unable to answer my question in any certain terms, I turned to the members of this forum, some of whom almost certainly can provide helpful and accurate information to help me in determining what to order from Tanner with some confidence in getting what I want.
Unfortunately, I missed an auction of a Lyman .625" RB mold, and have not found another, so far, though I would buy one if available and be fairly certain it would be what I want.

mhb - MIke

 

[Maven]

Answered you on the Cast Boolits site, Mike. However, you can make up for slight differences in diameter by varying the thickness of your patches. Also, virtually none of my moulds, even those that are custom made and/or for CF rifles and pistols, drop a bullet or RB of a given dimension even factoring in the alloy used. To your original point, I'd heartily recommend a Jeff Tanner mould.

 

[fleener]

Ok, so I ordered a .730 mold and my balls are .7305.

We got big squirrels in these parts.

Fleener

 

[Zonie]

Must be mighty big squirrels in your neck of the woods.

 

[mhb]

Maven and Fleener:

Thanks for the additional info. Virtually all of my RB molds produce cast pure lead balls very close to the nominal diameter, though I have not measured all of the actual cavities.

mhb - MIke

 

[fleener]

I have no idea on what the cavity measures.

Fleener

 

[mhb]

Fleener:

Since the Tanner molds are lathe-bored, I expect the cavity would be very close to the nominal diameter. An additional concern (perhaps unjustified) is that Geoff Tanner recently passed away, and the accuracy and overall quality of the current production may not be fully equal to the original, or so some have implied.

mhb - MIke

 

[cositrike]

I have 8 Tanner moulds and they all cast a good ball, that will hit the X if I do my part. I believe that I’ve only heard two or three negative comments on Tanner moulds, in all my years of muzzle loading. Not bad, if you think of the amount of moulds they have made. I’m sure there are other mould makers out there, if you’re not happy with Tanners accuracy.

 

[Flintfan69]

My goodness, you are talking of a variance of .001 to .003 in the diameter of a soft lead, patched ball used in a large caliber muzzleloader. Take his advice, order a .628 and you will most likely be + or - .001 of your target of .625. Your patching material will probably vary that much from lot to lot.

 

[fleener]

I would not hesitate to order another mold today from this company. Everything was first rate, including delivery time.

If you order it and it is totally wrong, I bet they would fix it. I would be surprised if there are any issues.

Your not buying $1,000 mold. Your spending less then $70. Order it and be happy.

Fleener

 

[Eric Krewson]

I have one Jeff Tanner mold, a .695 if I remember correctly. I use range lead, the stuff I use in the tanner mold is some I separated out when I picked it up because it wasn't very deformed when it hit the back of the berm and I suspect it was mostly wheel weights. Even with wheel weight stuff my mold will be pretty close to spec, maybe a thou or two over or under.

 

[mhb]

Thanks to all who have responded. I've decided what to do.
Fleener:
I doubt that a mold ordered from Tanner would be 'totally wrong', in respect to the diameter ordered, but the issue (for me) is the as-cast ball diameter, and Tanner has specifically stated that they will not be responsible for that, due to losses incurred in dealing with customers dissatisfied over that specific problem.
All: The information I really wanted, and asked for, is the relationship between the diameter of the Tanner mold cavities, as ordered, and the resultant pure lead cast ball diameter, as found by users of those molds. Relatively little information has been forthcoming on that point, which is a bit surprising. Still, it is evident that most users of Tanner molds are happy with them, and I'll just have to make my best guess based on such input as I've received, and take the plunge.

mhb - MIke

 

[cositrike]

Thanks to all who have responded. I've decided what to do.
Fleener:
I doubt that a mold ordered from Tanner would be 'totally wrong', in respect to the diameter ordered, but the issue (for me) is the as-cast ball diameter, and Tanner has specifically stated that they will not be responsible for that, due to losses incurred in dealing with customers dissatisfied over that specific problem.
All: The information I really wanted, and asked for, is the relationship between the diameter of the Tanner mold cavities, as ordered, and the resultant pure lead cast ball diameter, as found by users of those molds. Relatively little information has been forthcoming on that point, which is a bit surprising. Still, it is evident that most users of Tanner molds are happy with them, and I'll just have to make my best guess based on such input as I've received, and take the plunge.

mhb - MIke

Depending whether I have my lead at the correct temp, or too hot/cold, my moulds tend to give a ball + or - about .001-.003, if that’s any help. I don’t tend to mic them often. I order them around 10 thou smaller than bore and as I’ve already said, they’ll hit centre if I can hold the gun still

 

[RAEDWALD]

I have several Tanner moulds (now www.ballmoulds.com) and all are exactly as the size specified. As to the cast ball size, that is beyond the mould maker's control as it depends upon the alloy used, the temperature of the mould and of the metal. All he can do is give you a mould with the cavity as requested.

For a round ball mould of your desired cavity size James will give you exactly that. From then on it is up to you to adjust with alloys, patches and, possibly, beagling to make minor adjustments.

I shall shortly be ordering a belted ball mould from him with complete confidence.