Lyman Mold casts heavier Bullet then it should

[Graybeard96]

Howdy,
Had this Lyman Mold 429650BV for a number of years, never used it before until yesterday. Casts a nice Heavy Bullet which I am planing to use in my Ruger Super Blackhawk should a Grizzly decide to lean on me. The Lead I am casting with has a small amount of Zink in it which really should make it a tad lighter.
The Lyman Book says the Bullet supposed to weigh 300 Grain but my Scales tell me the Bullets are really 320 +/- Grain.

Me thinks, 20 Grain over would probably not go to well with the load Data shown in my 4th edition Lyman Cast Bullet Handbook on page 275.

Hmmm, should I contact Lyman for clarification or what would you do.

Cheers

[farmbif]

why not, will be interesting to see if they respond and if response is based on real testing parameters.

I might add that when I'm faced with bullets cast at odd weights I try best to extrapolate from proven data that is trustworthy.

[zarrinvz24]

That boolit has a gas check shank. Is that the weight after size/lube/check?

[Graybeard96]

Howdy,
Had this Lyman Mold 429650BV for a number of years, never used it before until yesterday. Casts a nice Heavy Bullet which I am planing to use in my Ruger Super Blackhawk should a Grizzly decide to lean on me. The Lead I am casting with has a small amount of Zink in it which really should make it a tad lighter.
The Lyman Book says the Bullet supposed to weigh 300 Grain but my Scales tell me the Bullets are really 320 +/- Grain.

Me thinks, 20 Grain over would probably not go to well with the load Data shown in my 4th edition Lyman Cast Bullet Handbook on page 275.

Hmmm, should I contact Lyman for clarification or what would you do.

Cheers

Just emailed Lyman a minute ago, will share there answer once I have one !

Cheers

[Graybeard96]

That boolit has a gas check shank. Is that the weight after size/lube/check?

I weighted them before setting a Gas Check-Lube and sizing.
Thanks

Cheers

[243winxb]

Lyman molds are regulated with their # 2 alloy. You need to test cast with it.

[243winxb]

Bullet Sizes & Weights – How to Vary Them




The bullet diameters and weights presented in this list
are based on the use of Taracorp’s Lawrence Magnum
bullet alloy (2% tin, 6% antimony, 1/4% arsenic,
91.75% lead).
Bullet diameters and weights will vary considerably
depending on the lead casting alloy used. This variation
can be as much as 1/2% on the diameter, and 8% on
the weight among the most commonly used casting
alloys. For example, a .358-158 grain bullet might
show a diameter variation of .002", and a 13 grain difference
in weight.
Of the most commonly used alloys, wheel weights (.5%
tin, 4% antimony, 95% lead) will produce bullets having
the smallest diameter and heaviest weight, with
such bullets running approximately .3% smaller in
diameter and 3% heavier than bullets cast with
Taracorp's metal. Linotype will produce bullets with the
largest diameter and lightest weights. This alloy will
produce bullets approximately 1/10% larger and 3%
lighter than Taracorp. Other alloys of tin and antimony,
with antimony content above 5%, will produce bullets
with diameters and weights falling between those cast
from wheel weights and linotype.
Alloys containing little or no antimony will cast considerably
smaller than wheel weights and in some cases
will produce bullets too small for adequate sizing.
Within the limitations given above, the weight and
diameter of a cast bullet can be adjusted by varying the
alloy’s antimony content.
The size and weight of bullets of a given alloy will also
vary according to casting temperature. Higher temperatures
will result in greater shrinkage as the bullet
cools, thereby producing a slightly smaller and lighter
bullet than one cast of the same alloy at a lower temperature

[Graybeard96]

Bullet Sizes & Weights – How to Vary Them




The bullet diameters and weights presented in this list
are based on the use of Taracorp’s Lawrence Magnum
bullet alloy (2% tin, 6% antimony, 1/4% arsenic,
91.75% lead).
Bullet diameters and weights will vary considerably
depending on the lead casting alloy used. This variation
can be as much as 1/2% on the diameter, and 8% on
the weight among the most commonly used casting
alloys. For example, a .358-158 grain bullet might
show a diameter variation of .002", and a 13 grain difference
in weight.
Of the most commonly used alloys, wheel weights (.5%
tin, 4% antimony, 95% lead) will produce bullets having
the smallest diameter and heaviest weight, with
such bullets running approximately .3% smaller in
diameter and 3% heavier than bullets cast with
Taracorp's metal. Linotype will produce bullets with the
largest diameter and lightest weights. This alloy will
produce bullets approximately 1/10% larger and 3%
lighter than Taracorp. Other alloys of tin and antimony,
with antimony content above 5%, will produce bullets
with diameters and weights falling between those cast
from wheel weights and linotype.
Alloys containing little or no antimony will cast considerably
smaller than wheel weights and in some cases
will produce bullets too small for adequate sizing.
Within the limitations given above, the weight and
diameter of a cast bullet can be adjusted by varying the
alloy’s antimony content.
The size and weight of bullets of a given alloy will also
vary according to casting temperature. Higher temperatures
will result in greater shrinkage as the bullet
cools, thereby producing a slightly smaller and lighter
bullet than one cast of the same alloy at a lower temperature

Interesting article:
My Caliper shows them at .431 to .432 before sizing.
Based on the Alloy I am using, I would think my Bullets should be lighter then 300 Grain.

Cheers

[Conditor22]

Harder alloy = lighter boolits

Higher casting temp = more shrinkage = smaller/lighter boolits

curious what percentage of zinc you a re using === alloy composition

[Graybeard96]

Harder alloy = lighter boolits

Higher casting temp = more shrinkage = smaller/lighter boolits

curious what percentage of zinc you a re using === alloy composition

I melted about 100 Lbs. Wheelweights into Ingots, perhaps 20+ Zink Wheelweights got into the mix by accident. Been casting with this miz quite a bit for the 357, shoots great no issues.

Cheers

[Dusty Bannister]

Weight comparable to previous alloy in the 357?

[Winger Ed.]

If you aren't using exactly the alloy they do, you'll get different weights.

I use a much softer alloy than Lyman does for my .459-- 405s I shoot in .45-70.
They drop around 424 gr. That's 5%-ish or so heavier than the load data calls for.

I always stay below max by 10% or there-abouts anyway, and never had a issue.

[Walks]

Sorry to be the cynic on this but I don't think you'll get much of an answer from Lyman. Their "customer service" reps know absolutely nothing about their products beyond product #'s and descriptions.
Unless you're lucky and they pass on your question to the one "maybe" remaining person who does know something.

Believe Me, I've tried.................

[reddog81]

20 zinc weights might be in the mix or 20 lbs of zinc weights? 20 individual zinc weights won’t really matter much in 100 lbs. 20 lbs of zinc would be a big problem.

[Graybeard96]

Sorry to be the cynic on this but I don't think you'll get much of an answer from Lyman. Their "customer service" reps know absolutely nothing about their products beyond product #'s and descriptions.
Unless you're lucky and they pass on your question to the one "maybe" remaining person who does know something.

Believe Me, I've tried.................

Sadly, seems like you are correct. Being a bit of a cynic myself I should not be surprised.

Cheers

[Graybeard96]

20 zinc weights might be in the mix or 20 lbs of zinc weights? 20 individual zinc weights won’t really matter much in 100 lbs. 20 lbs of zinc would be a big problem.

Just 20 or so smal Zink's not 20 Lbs.

Cheers

[44MAG#1]

Straight away I went to Lymans lastest Cast Bullet handbook and saw that their weights are LINOTYPE for that bullet with the GC not included.
Most alloys will cast heavier and then add the weight of the GC.
There we go.

[Multra]

If you have a chrono just start at the min charge and compare the velocities, should be quite close. I wouldn't worry too much testing loads in a super blackhawk, any book published load for a cast bullet is going to be a walk in the park for that thing.

[robg]

mine are usually heavier than the mold says by about 5% .if they are much heavier i add a bit more tin.

[JonB_in_Glencoe]

Myself, I would not worry about 20gr over, on a 300gr boolit.
Since you want a Grizzly load, just work up from starting load and watch for signs of pressure.