Ball weight to tight fit

[Tasbay]

Have noticed when loading my .50cals some patched balls defiantly slide down the barrels easier than others (yes I swab between every shot) and the tight fitting ones always hit considerably higher on target, more pressure and so on.
So yesterday I decided to weigh some and was surprised to find a difference of up to 10 grains in ball weight. I`m using a Lee double cavity mould and assumed first off one cavity may be larger than the other. If that was the case then it should be 50/50 in lighter and heavier balls but its not. So I`m wondering could it be the mould expanding as it gets hotter? Someone is going to know this, Thanks in advance.

 

[ADK Bigfoot]

When casting, your first part of a batch (as the mold heats up) may be lighter and smaller than those cast later. I usually find that most of my culls (returned to the pot for remelting and recasting) come from early in the batch. My heaviest occur near the end. The key for me is to put my first ten or twelve bullets into my sprue container (the can I cut my sprues in to) until I find my rhythm and the mold is up to temperature. It is not unusual for me to end up with fifty to one hundred bullets that are no more than two grains apart in weight. You can also get more consistent results by keeping your sprues and rejects in a container and returning them all to the pot at one time, rather than returning them to the pot as you cast.

I weigh sort all of my cast projectiles into lots of +/-1 grain.

ADK Bigfoot

 

[Rifleman1776]

As said, temp control is essential when casting. Get that heat up to about 700 degrees. Once you start producing quality balls then you can accurately test on the range. ML rifles are funny critters. Some shoot just as accurately with the smaller (.590") ball as with the larger, and heavier (.595") one. There is a slight difference in weight between the two. Your observation that the larger ball has a higher point of impact or POI is understandable for the reasons you asked about. I often used a smaller ball when shooting the offhand matches at closer ranges. e.g. 25 and 50 yards. For longer ranges I would go to the larger ball to raise my POI. Worked for me. But spend time at the range and do yer own thang.

 

[Phil Coffins]

Consistency in casting is a skill that anyone can achieve. Some molds require the pour to be done in one manner and won’t do well any other way. Round ball is one of the easier ones and can be done with a bottom pour pot. With all casting temperature and rhythm is important. I cast a 523 grain bullet with a dipper and will get a hundred that weigh +- one grain. How much sprue you make on each one among all the other details all adds up.

 

[hanshi]

I guess I must be a clod then. I visually inspect (casually) and shoot anything that looks okay. The way I now shoot I could make do with fishing sinkers.

 

[The Crisco Kid]

To each his own I guess. I always open the mold with a gloved hand and drop the sprue back in the pot. I have a bunch of Lee molds and I get adequate results from them but much prefer an iron mold. To the point of the OP, I have an old Lyman double 50 cal mold that casts two different diameter balls. It's marked .490. One cavity averages .489 and the other .484. I marked the larger cavity with a small center punch dent so I can tell which is which. I haven't shot them yet since the 50 is a rifle in progress.

 

[Brokennock]

I heat my molds, and keep them hot while adding lead (casting from a small hotpot), on an old hot plate. The aluminum mold seems to work better of I heat it up with the sprue plate down against the hotplate, the steel mold doesn't seem to matter, works great either way.

 

[user 34300]

Unless a ball looks perfect throw it back. Get a digital scale and weigh the balls. Lee molds need to be smoked. They need to be lubed. Do not get lube in the cavity. The casting temp depends on the size of the balls. Smaller is hotter. I'd be looking in the 800* range on 50s. You need a thermometer, buy one. Adjust the casting rhythm to get about a 3-second time for the sprue to freeze. Watch for lead getting between the cavities. You will have to determine if you mold want to be pressure or gravity fed. Preheating the mold it necessary. You can set it on top of the pot while the lead come up to temp. You should be able to cast the vast majority of the perfect ones within a couple of grains. IF not determine why the mold is not closing the same each time. Good luck.

 

[longcruise]

Do some have ridgelines around them where the surfaces mate? Do all the mating surfaces look clean and free of debris? Make sure that you hold the handles tight together when you pour.

Just afew things that I've encountered and overcome.

 

[Tasbay]

All good advice thanks guys. The absolute majority of cast balls are at 171 grains so could be a simple as holding the handles a little lose on some of the casts.
I usually discard the first half dozen or so and then go from there. At the moment looking at shooting the heavier balls from my GPR as it is too lose with the .495 balls that weigh 171 grains and a ticking patch. It preforms better with the tighter balls as getting blow by and scorching of patches with the 171grain balls, that shoot perfectly out of my T/C and Pedersoli rifles.

 

[nhmoose]

Weigh the balls. I use an electronic scale and separate by weight. The heavy ones are my serious match balls. The mid my non serious match balls, the low weights practice and hunting as deer and such have huge X-rings.

All balls will be within 3 grains heavy to light. 10 grains same mould will go back in the pot.

You also have a diameter difference also. wider balls are heavier. All from same Mould you're casting teck is bad. Wide balls will come from not closing the Mould every time. PAY ATTENTION!! Look every time to be sure it is completely closed. Soon you will tell by feel when you close it.

Casting takes a while to learn and become second nature by feel when you close properly.

I suggest to lookup "Castboolits" forum. I would give you a link but they have a ML forum and that would break the rules of this forum

 

[mooman76]

Mould temp will make a difference, slightly but shouldn't be ten gn. Make sure the mould is closing all the way. Some of the old ones, don't always line up like they should. You should be able to old it up to the light and not see any light. Also sometimes the mould will get a tiny speck of lead in between and that will keep it from closing all the way.

 

[Tasbay]

Have weighed all my cast balls and separated them 170-174grain & 175-180grain. Went to the range yesterday with a GPR that has been causing me issues with the cast balls as far as groups and patch destruction go. Fired a 5 shot group of the 175-180gr balls and got about a 1-1/2 inch group at 50yds. Then shot 3 171gr balls and got about a 8 inch group. Seem to have solved 2 issues ,one the GPR now has a ball patch combo it likes and the 171gr balls all shoot well in my T/C and Pedersoli guns. So just as long as I weigh the cast balls and separate them I should be ok fingers crossed.