Lyman 575213PH weights.

[Maillemaker]

So I got my Lyman 575213PH mold in and have cast up nearly 100 bullets with it. My weights using pure lead are averaging 525.61 grains. This is quite a bit lighter than the stated 566 grains.

I'm going to use this for my Pedersoli P58 to see if I have as much luck as Space Cowboy.

Here is my data:

http://i.imgur.com/tSMDgr3.jpg



522.7


522.7


523


523.5


523.7


523.7


523.8


523.9


524


524.1


524.1


524.2


524.3


524.4


524.4


524.4


524.4


524.6


524.6


524.7


524.7


524.7


524.8


524.8


524.8


524.8


524.8


524.9


524.9


525


525


525.1


525.2


525.2


525.2


525.2


525.3


525.3


525.3


525.3


525.4


525.4


525.5


525.5


525.6


525.6


525.7


525.7


525.7


525.7


525.7


525.7


525.7


525.8


525.8


525.9


525.9


525.9


525.9


525.9


526


526


526.1


526.1


526.2


526.2


526.2


526.2


526.3


526.3


526.3


526.3


526.4


526.4


526.4


526.4


526.4


526.5


526.5


526.5


526.6


526.8


526.9


526.9


527


527


527


527


527.1


527.1


527.1


527.3


527.6


527.6


527.7


527.9


528


528

[tmont]

Interesting! My shooting buddy just received a 575213OS which is advertised to cast a 460 grain bullet. Instead it casts a bullet weighing around 529 grains. I have a Lyman wadcutter mould which casts a bullet running in the neighborhood of 360 grains when it is advertised to cast 315 grains.
Are Lyman moulds usually that far off?

[Smosin]

I have a Lyman minie mould I got in a trade quite a while ago, but have never used. I don't know exactly what wt it is, or actual cast diameter. Old style? New?
It is marked "575213AZ". Anyone know what the "AZ" might indicate, if anything?

[Rebel Dave]

A Z is something to do with the manufacturing of the mold. You have a standard Lyman Minnie mold.

Rebel Dave

[Smosin]

A Z is something to do with the manufacturing of the mold. You have a standard Lyman Minnie mold.

Rebel Dave

Thanks for that info!

[Ron/The Old Reb]

The letters tell Lyman which cherry was used and the vintage of the cherry.

[Hickok]

Maillemaker, my Lyman PH mold is about 10 years old. I just cast some mines today and they are averaging 561 grains, and run .577-.5775" for this batch.

[Maillemaker]

Hmm. This is the scale I am using to measure them:

http://www.midwayusa.com/product/713372/frankford-arsenal-micro-reloading-electronic-powder-scale-750-grain-capacity

Steve

[Scott Kurki, 12475]

By analyzing the data provided, it appears that the mold will eventually cast the advertised weight.

[Hickok]

Maillemaker, I have the same brand scale as you, but a different model;http://compare.ebay.com/like/370843504068?_lwgsi=y&ltyp=AllFixedPriceItemTypes&var=sbar

Sure is a large variation in your mold and mine. :confused:

Even if your lead had an alloy in it, I wouldn't think it would account for such a light weight. I wonder if Lyman may have changed the depth of the base cavity? My base cavity is .216" deep. If yours is deeper, maybe we have an answer.

[Maillemaker]

By analyzing the data provided, it appears that the mold will eventually cast the advertised weight.

There is no trend indicated by the graph - I merely sorted the data from lowest to highest weight. This is not a chronological order of casting.


Even if your lead had an alloy in it, I wouldn't think it would account for such a light weight. I wonder if Lyman may have changed the depth of the base cavity? My base cavity is .216" deep. If yours is deeper, maybe we have an answer.

I am casting with 99.9% pure lead purchased from rotometals.com.

My scale calibrates to the included calibration weight OK.

http://i.imgur.com/aAX1Fi9.jpg
http://i.imgur.com/aTKIK2l.jpg

The truncated cone of my base measures .219" deep.

Steve

[Scott Kurki, 12475]

I see that you are using an electronic scale. I have a Lyman xp100 (I believe) that I had issues such as this variance with when it was new. I read a post where someone suggested that there was a 24 hour burn in requirement for the scale. I plugged my scale into AC and left it on for a few days (because I forgot about it). The scale seems fine now, no more creeping variances. Perhaps you scale needs a burn in or something?

[Hickok]

Steve, it would seem we have an enigma wrapped in a puzzle! Wonder if Lyman may have slightly changed the ogive on the nose of the bullet over the years? Still, they should have made note of any weight change on the die box. My average bullet length is 1.058"

This one has me flubbergusted!

19951996

[Maillemaker]

Tonight I went over to my neighbor's house (he reloads, too) and put my bullets on his Frankford Arsenal digital scale. It's just like yours.

My bullets measured within .5 grains on both scales.

So the only thing I can figure is my alloy is not pure lead.

Steve

[tmont]

Steve: I don't know about your lead composition, but as I noted earlier, the three Lyman moulds I have access to all produce bullets significantly heavier that what the mould is advertised to cast.....so looking at your situation in addition to my experience, one would have to conclude their advertised casting weights are inaccurate. I wonder if Lyman does not have a quality control issue. Nice moulds, but not even close to the advertised casting weight.

[Ron/The Old Reb]

Just a thought. But could it be as the cherry wears that is what is causing the variation in bullet weight. And not quality control. Only problem I have had with Lyman molds, and I have a lot of them, is some times you get one that is a B---h to brake in.

[Hickok]

Steve, I know what I am about to say is not very "scientific" but pick up two of your ingots of lead and tap them together. If pure lead they should not "ring" but give you a dull "thud" sound. Kinda' West Virginia Hillbilly slang, but the only way I can describe the sound. If it gives a "ping" like a hammer hitting steel, you have an alloy, not pore lead.

I just went and tried my different ingots. Pure lead, thud, 1 to 1 lead and wheelweight= ping, pure wheel weight= ping.

I can cast a Rapine 475 ringtail bullet using pure lead and again using WW metal and the weight changes 15 grains, about 480 for pure lead vs. 465 for ww.

Also the ww bullet will gain .001" diameter over the pure lead bullet.

I have had trouble in the past with what I "thought" was pure lead. The only thing the minies would do is keyhole. I would dig some up and no signs of rifling marks. I really knew better, because the bullets looked too shiney and mirror-like coming out of the mold. Not just nice and silver like a good lead minie, these looked like chrome. The fellow I got the lead from assured me it was absolutely pure lead. I then tried the
"acoustic test" after wasting some time and powder, and got a "ping" for my answer!

I guess sometimes in shooting we get a "ping, and others times we get a "thud!" :rolleyes:

[Maillemaker]

My ingots go "thud". They should be pure lead - they are purchased from Rotometals.com and are advertised as 99.9% pure lead.

Now I do cast WW bullets and pure lead bullets from the same pot. But I am always careful to fully empty the pot when I switch from one to the other. There is only a tiny residue of lead remaining. That's the only contamination I can think of, but I would not think that would so drastically alter the weight of the bullets.

My RCBS-Hogdon .578 bullet is weighing in at 424 grains, and it is advertises as a 414 grain (measures too heavy by 10 grains).
My Lyman 575213PH .575 bullet is weighing in at 526 grains and it is advertised as a 566 grain bullet (measures too light by 40 grains).

So I guess it's probably not alloy or I would expect both measurements to be low.

Steve

[Bullseye54]

Perhaps it is the variences in the plug (depth or profile) or if inserted completly each time.. It wouldn't take much to change the weight.. If you have a used mould, then the plug could have been mixed with another mould... If the bullet is round and concentric, then the lenght and plug is all thats left.. Plug is not in completly , just a frogs hair difference on each bullet cast it would give a varience in the weight.. Even a couple of thousands in the insertion depth of plug ...

[Maillemaker]

The mold was purchased new.

The mold throws pretty consistently when up to temperature. If you look at the graph of the data you will note that the graph is pretty linear until you reach approximately 524.4 grains, and then it tapers off quickly.

Upon examining the bullets on the low end of the weights, you can see wrinkles in them - the mold was not up to temperature yet. Normally these bullets, while slightly wrinkled, were not wrinkled enough that by eye I would have rejected them. But I now believe that the wrinkles are indicative of incomplete mold fill-out, resulting in lighter bullets.

Of course, also when you look at the graph you can see how this "taper off" pulls down the average weight.

What I do now is weigh all the bullets, but discard any data that falls off of the linear portion of the graph. This is usually most pronounced at the bottom end of the graph but sometimes there is a slight uptick at the high end also.

By eliminating the outliers I get a more accurate average bullet weight. I then discard any bullets that are outside of +/- .5% of the average weight.

When you eliminate the outliers, the bullet weights vary high-to-low about 2 grains (about 524.4 to 526.4). This is about five thousandths of an ounce or about 1/8th of a gram.

Of course I only have to do this once on a set of bullets to find out the average weight and the max/min. After that I just weigh my bullets and discard those outside the acceptable range. I find my discard rate is usually 5-10%.

Steve

[R. McAuley 3014V]

Gents, I have owned all four versions of this mould from the first 575213 (with deep base cavity), to the next version made with the shallow-vee base cavity for the Parker-Hale (575213PH); the "old style" remake (575213A OS) with kind of a medium deep base cavity; to the "A-" suffix, with the base cavity like the "PH" but with a small flat in the apex of the hollow base. I think somewhere back in the archives is a photo of the four mould designs, showing their differences, and there was also a difference in the weight of each. The original Lyman Ideal mould 575213 was supposedily a 460 grain minie but cast in the 505-508 range, while the Parker-Hale design minie was supposed to be a 525-grain minie, but it often only cast in the 505-518 range. The "OS" mould was to have been a return to the first Ideal mould design but did not match the original 460 weight. Most of the time the "OS" cast in the 493-498 range using plumber's lead. The "A-series" featured a change in the ogive shape of the point and both the depth and spacing of the grease grooves which had an effect on bullet weight.

Below is a photo of the Lyman 575213 mould on right and its immediate successor, the 575213A designed "OS" (or Old Style) on left with castings of the respective moulds (note the base depth and skirt thickness). Ball on left weighs 593-grains; the ball on right, 505-grains (using Hornady GS-1500 electronic scale).

http://i267.photobucket.com/albums/ii305/rmac1023/575213pics004_zps60d5f51f.jpg

[Hickok]

Richard, my Lyman PH mold has 575231AV stamped on it, if that means anything.

[R. McAuley 3014V]

Much like Ron had mentioned earlier, Lyman explains: “Each mould block is stamped of course with the bullet number it will cast. The letters following this number are our reference which tells us exactly which cherry was used. This also tells us its vintage. There are block numbers, each mould will have the same numbers stamped on both halves. This matches up the mould halves in case they are separated.”

Below is a photo of the original Lyman 575213 mould on right and its immediate successor, the 575213A designed "OS" (or Old Style) on left.



http://i267.photobucket.com/albums/ii305/rmac1023/575213Apics009_zps92fc3111.jpg

[Maillemaker]

My mold is stamped on one side:

LYMAN
575213AV
501
2H

On the other side:
LYMAN
01-10
501

Steve

[Hickok]

Thanks Richard, I didn't know what the "AV" and "AZ" were for.

[R. McAuley 3014V]

At one time, I had a more elaborate chart illustrating some twelve different bullets but lost it when my external harddrive crashed.

http://i267.photobucket.com/albums/ii305/rmac1023/BulletChart_zpsfdfd723b.jpg


As for the powder-to-ball ratios shown, the 1:8 was the powder-to-ball ratio designed for the Model 1855 Rifle, the 1:10 was the French metric, and other European powers used the 1:11 or 1:12 ratios. Another way to view these powder-to-ball ratios is to compare the 1:8 to the use of double-fine (FFg) powder vs. the 1:12 ratio representing triple-fine (FFFg) powder.

There may likewise be a way to equate these to slow or fast spiral rifling, but a word to the wise: don't confuse Greenhill's equation with small arms. Dr. Greenhill taught physics and mathematics at the Royal Artillery School, and his so-called "ballistics equation" that is splashed all over the Internet that many rely on for judging bullet length vs. spiral rate was an equation chiefly applied to iron and lead-tin alloy artillery projectiles, not pure lead bullets for small arms.

[Maillemaker]

There may likewise be a way to equate these to slow or fast spiral rifling, but a word to the wise: don't confuse Greenhill's equation with small arms. Dr. Greenhill taught physics and mathematics at the Royal Artillery School, and his so-called "ballistics equation" that is splashed all over the Internet that many rely on for judging bullet length vs. spiral rate was an equation chiefly applied to iron and lead-tin alloy artillery projectiles, not pure lead bullets for small arms.

I have read other accounts that say he developed it for lead core bullets:

http://en.wikipedia.org/wiki/Rifling
"In 1879, George Greenhill (http://en.wikipedia.org/wiki/George_Greenhill), a professor of mathematics at the Royal Military Academy (RMA) at Woolwich (http://en.wikipedia.org/wiki/Royal_Military_Academy,_Woolwich), London, UK[9] (http://en.wikipedia.org/wiki/Rifling#cite_note-9) developed a rule of thumb (http://en.wikipedia.org/wiki/Rule_of_thumb) for calculating the optimal twist rate for lead-core bullets."

http://www-history.mcs.st-andrews.ac.uk/~history/Biographies/Greenhill.html
"Greenhill's work was mainly on elliptic functions. He was interested in their applications to dynamics, hydrodynamics, elasticity, and electrostatics. As might be imagined given that Greenhill spent most of his life working in a military establishment, his work was often directed towards applications to ballistics and other military applications. Love (http://www-history.mcs.st-andrews.ac.uk/%7Ehistory/Mathematicians/Love.html), writing in [2], explains applications of the theory of the motion of a solid in a fluid made by Greenhill in 1879:-
Greenhill applied this theory to give an account of the steadiness of flight conferred upon an elongated projectile by rifling. He determined the least angular velocity about its axis for which steady motion of a solid of revolution can be stable. ... This practical application of what was regarded as a recondite mathematical theory earned for him much renown at Woolwich. "

And it has been improved upon:

http://en.wikipedia.org/wiki/Miller_Twist_Rule

Steve

[R. McAuley 3014V]

You should perhaps refer to Greenhill's Notes on Dynamics (1908), specifically that addressing the problem of stability in flight of an elongated projectile (top of page 206), and continuing on to the "Table of Rifling for Stability of a Projectile" calculated by Captain J.P. Cundill, R.A. and enlarged by Mr. A.G. Hadcock, R.A., with respects to cast-iron common shell; Pallister shell; solid steel bullet; and solid lead and tin bullet, at the link below:

http://books.google.com/books?id=NhxRAAAAYAAJ&lpg=PA228&ots=cJC_3VZ-53&dq=Notes%20on%20dynamics%20(1908&pg=PA218#v=snippet&q=iron&f=false

You might skim over the derivations provide therein continuing on pages 216 thru 218 to the final conclusion referring to Benjamin Robins' treatise of 1747 addressing this very subject, as well as the experiments conducted by Whitworth relative to his 1:18 rate spiral for all calibres up to six calibres long. As Greenhill explains (top of page 219) "These Notes on Dynamics were prepared originally for the Advanced Class in the Artillery College...".