consistent cast bullets

[DCB]

What are some methods for consistent bullets? Weight variance (+-) diameter at the driver band.
What do you do to control these two Variables, or others that come to mind
Thanks Dave

[marek313]

What are some methods for consistent bullets? Weight variance (+-) diameter at the driver band.
What do you do to control these two Variables, or others that come to mind
Thanks Dave

Consistent alloy , consistent casting temp, consistent casting speed, good mould obviously. Most importantly you need practice , practice , practice to make it perfect and consistent. Thats the most important thing i think. I'm sure you will get answers including PIDs and testing your alloy but i dont think those are anywhere as important as practice.

[cupajoe]

Consistent alloy temp and consistent mold fill. I use a PID for temp control. As far as the fill, I strive for the same size sprue when pouring and once the cavities are filled, I count to 10 or 15 then cut the sprue and dump. The count time varies with the mold cavity size, alloy temp and mold material.

[gwpercle]

I pressure cast with a ladle that has a spout on the side , like the Lyman ladle.
Gang moulds and bottom pour pots just never could come close to the "perfect" boolits I like to cast.
After a few years of pouring a lot of imperfect and so-so boolits I went back to basics . Single, double and triple cavity moulds , a Lee Magnum Melter that holds 20 pounds and a Lyman ladle ...
Pressure Casting and a consistent technique , honed by 50 years of practice , works best for me .
Gary

[mnewcomb59]

With a bottom pour pot ad 2 to 6 cavity molds, my good consistent weight bullets come only when the mold is run like a robot.

I do not keep any bullets cast before I have a 3 second liquid sprue.

At my rate of casting, if the sprue starts staying liquid for 5-8 seconds or more, I always start to turn the pot temp down rather than slow my pace or cool the mold. If my sprue is staying liquid too long but the pot is so cool that the spout wants to freeze, I will turn the pot up and start to dab the bottom of the mold on a wet cloth between casts.

Usually you find the sweet spot of pot temp within your first 15 casts on your preheated mold. My Lee pot needs the temp to be turned down as a pot empties.

I am a big fan of fillin 'er to the top and making a lot of bullets from the same pot rather than trying to mix the alloy the same again in the future. I usually keep my soft lead, wheel weights, type metal and pewter separate. It takes a calculator to come up with an alloy that has equal parts tin and antimony from my ingredients. Once I do the math and weigh the ingredients and make a pot full I have been making a pot full worth of whichever mold that pot was meant for, even if it takes 3 sessions. It also means you have 900 9mm HPs that only need expansion tested once.


I have been using 1-1-98, 2-2-96, 3-3-94 and 5-5-90 lately with my hollow point and cup point molds. I should just make a 60 pound batch of 5-5-90 and dilute with pure as needed, which is what I might do tonight. Better than licking doorknobs at the bar! Oh wait, they're closed anyways

[DCB]

I will give all that a try.. Right now my pid reads 740 and I get good filled out bullets.
The biggest problem is trying to maintain the same size spru.
ill work on that and the speed, sounds like I need to slow down?
Dave

[lightman]

Consistent alloy , consistent casting temp, consistent casting speed, good mould obviously. Most importantly you need practice , practice , practice to make it perfect and consistent. Thats the most important thing i think. I'm sure you will get answers including PIDs and testing your alloy but i dont think those are anywhere as important as practice.

I gotta agree with this!

You try to make everything as consistent as possible. Then practice causes you to be more uniform with your cadence and timing.There are a lot of tricks that will help but theres no replacement for experience. PID's make it easier to control the pot temp but many of us cast long before a PID was ever used. Many of us pre-heat the mold on a hot plate. And we have a member here that provides an economical way to have alloys tested. (Thank You, BNE) But mostly you just need to pour a lot of lead!

[popper]

I run about 720 and trying to get that lower. You are pouring heat into the mould that is loosing heat - try to maintain the cycle of adding and removing heat consistent. Heat transfer is caused by TEMP difference. Pressure on the handles make a difference too. Al. mould expands (cavity dia. SHRINKS) and alloy contracts at the same time, brass and steel not so much. Fill the cavities quickly as you can without plugging the fill hole and allowing venting to remove air. Dribbling causes wrinkles. Some have thought air bubbles in the melt cause voids in the cast, IMHO it's very small impurities that outgas. I will always claim that dimension difference have more effect than voids. Sprue size is another problem. Consistency helps, timing sprue cut to allow proper base fillout gets tricky and is learned by experience. You can toe-tap count if the sprue size is consistent or wait till it changes color for not-so-consistent. Same for holding blocks open after drop - for me opening, tapping bolt and closing work. Presently working on sprue cut method for the most perpendicular(flat) base. Knocking, gloved hand, or a rig I made to cut solid sprue. So far, gloved hand is working best but testing not compete. I did turn the mould around in the handles and find slightly better results. Pulling toward the handle vs away.
I once tried weighing cast (rifle only) into a 'grid' of weight, but then re-weighed and found the 'grid' changed! Always got a few light and heavy but the middle ones 'moved'. Then micd the outliers and found the difference was dimensional. Surprisingly, light, heavy and 'normal' shot the same day, same load, etc. gave vert stringing. Actually, 'normal' gave the same result. Not a BR shooter so I just cast, toss the obvious bad back in the pot and shoot everything else.

[fredj338]

All good points. I pressure cast with a bottom pour pot. PID on my hand casting setup, my Magma just runs as is. Since I size everything, I don't worry much about size variation. Weight, also not a big deal but for extreme accuracy loads. For those I am weighing bullets anyway & trying to stay +/- 1/2gr.

[DCB]

Thanks, Looks like I have a lot of practice to do.
Thanks again there was a lot of help.
Dave

[tmanbuckhunter]

I have spent a lot of time trying to get super consistent and gave up with it. Now I just run a consistent temperature, keep the alloy fluxed often, and run the mold like a robot as stated by someone else. I visually sort my boolits for defects, PC, and then weight sort. The best I can do is within 3 grains, so I separate all of the boolits, toss the outliers to the pot, and then keep them in marked ziplock baggies in their own containers. Takes away the stress and then your ammunition is consistent regardless without having to do very much remelting. If I cast 400 bullets in a setting, I'll usually end up with 3 different bags of the same bullet and about 390 out of that batch after removing visual defects and the outliers with air pockets.

[megasupermagnum]

Most of your consistency is found during casting. If you cast with 50% visual rejects, you can be sure even the great looking remainder is not perfect. Some people are more picky on what a "good" bullet is. Weight sorting is the next step for anyone wanting the most consistent bullets, not just cast bullets. A lot depends on size. Something like my 600+ gr shotgun slugs, I wouldn't worry about plus or minus 1 grain. On the other hand, something like a 30 caliber 170 grain, I don't allow more than a plus or minus .2 grain variance. If you do a good job casting, 90%-95% of your bullets can fall into this .4 grain window, and the rest can be melted. Weight sort AFTER you visually sort.

For the most part I only visually sort. If your bullet is not sharply filled out, with a sharp base edge (less important if gas checking), it wouldn't matter how consistent they weighted.

[country gent]

All moulds like different things to start with. I ladle cast from a big pot ( 100 lbs), this mass maintains a very consistent temp easily and a stable base of alloy. I have "vented" my sprue plates on all my moulds but the Lees they are to thin for this. I found this to help with my technique. I run 2 moulds in tandem to give time to cool but not to much time.

My technique is to fire pot up and bring to 720* or so. I set the first 2 moulds on the warming plate on the pot when UP to temp I flux good and sit ladle in the alloy give it 10 mins to heat up and warm ladle. I then fill first mould and set back on tray fill second mould and cut sprue on first drop bullets and fill repeat. I make 8-10 pours on each mould and discard those bullets just because. I then start casting for making bullets maintaining cadence . When I fill a mould I dont pour for a sprue but fill ladle full and fill farthest cavity then closest and let extra flow back into pot until ladle is empty. This keeps the bullet molten longer allowing better fill out, fives more time for air gasses to escape and with the vented sprue plate a very consistent sprue.

A run of 400-500 550 grn 45 cal bullets will vary less than .5 grns over the entire run. My moulds are steel and brass.

Cast at a pace that keeps the mould in temp range, maintain this pace and remember when casting cast when sorting sort dont try to do both at the same time

[charlie b]

I just have a lot of rejects

Yep, consistency is key. I am not that consistent but it just means it takes me longer to get a pile of good bullets. I don't shoot more than a hundred a week so it isn't that big a deal to me.

Pistol is different than rifle. For pistol I merely reject the visually flawed. A variance of a few grains won't make any difference that I can see out to 50yd. I usually only reject the first few as the mold gets to temp. Or the ones that I 'flub' the cast.

Rifle I visually sort. Then weigh. I usually reject about half the ones that look good. I look for +/- 0.5gn. That usually is good enough for MOA or better. After PC and sizing I weight sort again and some get rejected here as well, but, they go in my 'plinking' bin. If I am after better accuracy I weight sort to the nearest 0.1gn and am more critical of visual defects.

[GhostHawk]

Ideally it should almost be Zen like. No thoughts, your just "doing" Don't have to think about it, its all muscle memory. When the leads hot you sit down and start casting, first thing you know your tired or the pots empty.

The other thing, don't sweat the small stuff. They all shoot. You want to sort 20 of the most perfect ones for hunting, fine.
But I stopped weighing mine years ago.

Consistent alloy does help, find a routine that works for you and makes good bullets and let it flow.

[JonB_in_Glencoe]

Here is a fairly good run down. But mostly, Practice makes perfect.

http://castboolits.gunloads.com/show...stency-applied

[DCB]

Thanks for all the comments.
I tried some pressure fills today and they were pretty good. I discarded the first few cast from the mold. the temp was around 740*. I should have my new pot on Tuesday, Its 25#.. The lee I am using is a 10# pot and the temp changes goes Up after about 25 or so castings and the flow changes as well.
Dave
Edit
(I changed down to up. I was pretty tired when I posted this)

[JonB_in_Glencoe]

I had one of those Lee 10 lb pots, I could never get use to, for just the reasons you mention.

[DHDeal]

I shoot for 750°, use consistent alloys, pressure cast using an old RCBS ladle with the spout opened up, I cast fast and use a pot that'll hold approximately 50 pounds. I do this regardless if I'm casting 550 grain BPCR bullets or using a 4 gang MP 32 caliber mold.

I've found that when the bullets start to get slightly frosty the bullets will be as perfect as I can get them.

[wv109323]

I cast for .45 acp , .38 Spec. and 9mm. The things that improved my casting the most are a PID and a hot plate.
Things that help are pouring directly into the sprue plate hole (get the lead into the mold quickly).
Keep the pot over 1/2 full. Again the lead flows quicker out of pot when the pot is full. I preheat the mold on a hot plate. I turn the mold and heat the sprue plate right before I start casting. I pour a generous sprue.
A cold sprue plate will cause the base of the bullet to be rounded.
The most important part of a cast bullet is the base and the corner between the side and base of the hullet.
I shoot NRA bullseye pistol. Last year I cast up some 200g. SWC. I culled the obvious rejects. I then picked 10 of the worst bullets I could find.
I ransom rested the 10 worst bullets. They grouped into 3" CTC. I average about 2 to 2 1/4" @50 yards. The best group I have shot with my cast is -1 1/2" @ 50 yards. So bullet base is somewhat critical . Some say it is more pronounced in their experience.
This is for target loads in a pistol. Rifle loads may be more critical.