.525 Gr Pedersoli 10 gr spread

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  • Last Post 09 February 2013
johnefelts posted this 15 November 2012

Im casting using a .525 grain pedersoli for my Sharps .54, here is the thing the closest ive poured is 534 grains and thats not all, the weights are not consistant and go all the way up to 549 grains,the source of the lead is from high line wires which should be pure lead.Any thought?

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linoww posted this 15 November 2012

Is it the ring-tail bullet? And if so what make? I am surpised by the weight spread as my 585g pure lead Minie-balls are pretty uniform

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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onondaga posted this 15 November 2012

http://www.castbulletassoc.org/view_user.php?id=6934>johnefelts:

Common causes for that kind of weight spread are:

Inconsistent hand grip on mold handles

Mold not closing consistently due to burrs or improper cleaning and lubrication

Splatter on mold faces and/or alignment keys

Thermodynamics running all over the place from poor pot temperature control

Thermodynamics running all over the place from irregular casting cadence

Casting into a mold that has not been pre-warmed to 100 degrees less than pot temperature or a mold that has not been brought up to working temperature by casting.

Casting into a mold that is too hot from over heating at pre-warm or too fast of a casting cadence

Variations in mold fill out caused by any of the above can be severe enough to cause even more weight variation than you are getting. Casting cadence is usually the hardest for a new caster to iron out. You should be dropping bullets from your one or two cavity mold 3 to 4 times a minute and not stopping to check them while you are casting. Throwing cut sprues into the pot destroys thermodynamics, save them and add them when you start a new potful.

Even if your casting is perfect and bullets are all within 1% weight of each other for match grade accuracy, their actual weight average may be no where near the listed weight for the mold. Learn to accept this. Mold manufacturers use the alloy they choose for mold design, You have the metal you have and it is not the same.  Also as mold cutting tools wear from production, the molds vary and bullet weight changes. Be more concerned with your alloy being suited to the job and improving your casting  and mold maintenance skills.

The ideal pot temperature is 100 degrees hotter than the point your metal reaches full fluidus for your particular alloy. Casting cadence is what maintains mold temperature for good bullet fill-out. Casting is an art and a science, it is not just dumping metal into a hole. Every problem has a cause, casting has been going on for many thousands of years and it is just a matter of learning to read mistakes and correcting  them to get excellent castings.

Pure lead is great for getting the softest bullets possible, if that is what you desire. However, 1-2% Tin added to pure lead will significantly improve flow quality of the metal during casting and have a minimal effect on bullet hardness or weight. Also pure lead casting temperature is very hot and generally the top end for most electric melting pots. Pure lead begins to melt at 621.5 degrees F.  and full fluidus is higher, so, a pot temp of about 750+ is needed for the best casting of pure lead and nearly constant fluxing and skimming is necessary at this high heat to keep the top of the melt clear of oxides if you are ladle casting. I can do it, but that ain't easy.....add some tin and drop the temperature.

Gary (Retired Casting Analyst)

The research animal Ethics Committee at the State University of New York at Buffalo would not allow me to teach a Chimpanzee to cast gold crowns for the Dental students as a demonstration, but I fully believe I would have been successful. So, there is hope for just about anybody..>

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linoww posted this 15 November 2012

Gary i throw sprue into my pot as casting into pot the last 25+ years and have yet to see a problem with casting match grade bullets.A cadence of a cast every 33.3333 seconds for a 500+ bullets is too fast.Mold block size/material plays into this as well.

IMHO a 10g weight swing and a 54 Paper Cartridge Sharps isn't going to make a difference in measurable accuracy anyhow.

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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onondaga posted this 15 November 2012

http://www.castbulletassoc.org/view_user.php?id=807>linoww:

I believe you can achieve a thermal balance when tossing sprues in at a reasonably constant rate. but that does add objectionable oxides to the top of the melt and can slow casting cadence irregularly. I don't recommend  it for a beginner developing casting cadence , but an artful and consistent caster can do that. I cut 6 cavity mold sprues directly back into the pot, but surely would not recommend that to a beginner having problems either. Dropping big sprues directly back in is clearly a safety hazard many should avoid also. I cast with glasses, gloves and a leather welders apron while checking 6 cavity mold closure frequently for splatter without breaking cadence. That is a little much for new casters.

George, the best place to put a regularly timed pause in casting if you need to slow down is to pause after opening the gate to cut the sprue , then pause before opening the mold to drop bullets. I drop bullets about every 17 seconds with a 1-2 cavity mold and about every 25 seconds with a 6 cavity mold. For me the 6 cav molds need a longer pause after cutting or they overheat.

Yes big ones need more time too. My shotgun slugs and .690 round balls sure do. He is casting a big one there so he will need to be slower.  Probably 2 drops a minute would be a better recommendation.

Gary

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Michael K posted this 15 November 2012

Hi there, Are you using a bottom pour pot, or using a ladel? For my BP slugs a ladel works best for me. While holding the mould and ladel horizontal I nuzzle the ladel spout up to the spru hole. In unison I slowly rotate the mould and the ladel 90 degrees taking a couple of seconds to do this allowing the mould to fill. I leave the ladel against the mould for a count of 6, then I lift the ladel off the mould and allow a nice spru puddle to form. The heavier the bullet, the bigger the puddle I allow to form, being watchful that as the spru hardens and flashes over no dimple in the spur over the pour hole forms. By keeping the ladel in contoct with mould it allows time for the mould to fill, air to escape, and as the metal cools drawing metal in from the ladel. If I don't take the time and quickly fill the mould and leave smallish puddle t is common to see a dimple get drawn in as the spru flashes over indicating the cavity was not full. Hope this helps, Michael

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linoww posted this 16 November 2012

I do the same as black and blue on heavy ML bullets.

Gary i cant say a particular time is magic as a cadence its more of a “feel” with each particular mold.I also often use a wet rag to cool down the plate if the mold seems to like it hot but the sprue cools too slow.I throw those in as well as the wet rag just steams and no water is left on the puddle.I also use a small fan as well on the opened block and that helps too. I cast with no gloves and in a tee shirt if the shop is warm enough.I use a medium soup ladle for bullet/sprue manipulation and my mold wacker for opening and closing the mold.I am a Neanderthal to most in my casting system i bet.No- probably Australopithecus Robustus.(they used cruder tools)

"if it was easy we'd let women do it" don't tell my wife I said that!

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johnefelts posted this 16 November 2012

ummmmh, you guys are talking way over my head!!!I just want to pour bullets that are with in a couple grains of each other.

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99 Strajght posted this 16 November 2012

If you want the same bullet everytime, go back and reread everything that was said. Every pore has to be the same every time. With practice it will all become more do able.

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onondaga posted this 16 November 2012

http://www.castbulletassoc.org/view_user.php?id=6934>johnefelts:

Pouring bullets within a couple grains of each other sounds very reasonable, but it actually is not reasonable at all with a 525 grain bullet. Bullets within 1% of each other by weight  are considered to be weight matched for competition by a lot of top shooters including myself. The 1% of 525 grains is 5.25 grains.

Half of the 5.25 grains is 2.625 grains. The way I use that number 2.625 in your case is to weigh all of the bullets and put them in rows by 1/10 of a grain.

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johnefelts posted this 16 November 2012

Thanks Gary that makes more sense,no Im not competing but I want my shots to go were Im aiming on the animal,thanks guys for your help I think I will take the advice and see were Im at in 6 months...

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shovel80 posted this 04 February 2013

It's Not reallly all that difficult to keep your weights within Less than 1 grain in a 500+ Grain Bullet!.......I do it with Lyman 535 Gr. Postel and Buffalo Arms 520 Grain Money Bullets!..

Gotta keep the cadence consistent, and the Melt temp. Close too!......I weight each bullet as I cast them. If Not with in about .5 Grain, they go right back into the Pot. The Only time I have much of a variance in weight is when I start casting, and if the temp changes.

Terry

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corerf posted this 06 February 2013

not trying to be funny, but a 700 degree bullet is hard to weigh. I burn the hell out of myself when I sort bullets, even with tongs, while they are hot.

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shovel80 posted this 09 February 2013

I wear gloves,Thin Cotton gloves, I double them up... and pick up each bullets right after I drop it out of the mold, set it on the electronic scale, and then lay it on the towel at my left in order of cast. And that's the way I shoot them too, In the order cast!

Terry

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Lefty posted this 09 February 2013

I do most of my casting during the winter and in an unheated garage. That makes temperature control of the melt and the mold a bit more challenging. My approach is that any bullet with any visual imperfection (any rounding of an edge is an imperfection) goes back into the pot. Others I weigh in due course if I am going to use them in a match. I group them into .3 gr lots. Ultimately I keep 5 lots (1.5 gr spread) and shoot them in order by weight group. I would say 1-2% of the bullets I weigh are rejects.

This process is easy and fairly fast. Warm weather helps a bunch but it is harder to find time to cast in the summer.

Jim

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