What am I doing wrong? Sprue cuts out chunks from the bullet...

[MuthaFunk]

Some of my boolits have chunks of lead cut out of the bottom of the boolits where each sprue plate hole is. Others look perfectly smooth on the bottoms. Is this because I'm not waiting long enough before I break the sprue off?

What am I doing wrong?

[Kraschenbirn]

I'd say you've answered your own question. Sounds like you're trying to cut the sprue before it's completely hardened. Wait until the sprue 'puddle' turns a dull, frosty gray before tapping the plate. Also, you might try backing your temp back a little, too. The higher your alloy temp, the longer it takes for the sprue to harden.

Bill

[jsizemore]

If your fillout is good then your lead and mold temps are good. Chunks out of the base of the boolit and/or lead smear across the top of the mold and/or the bottom of the sprue plate means your cutting too soon.

[runfiverun]

the good news is it doesn't affect things too much.
but like said above it's nothing more than a timing issue.
either keep a running count in your head or hang a battery powered ticking clock behind your casting bench.
fill the mold, run off a 5 count, break the sprue, look at the base and dump.
adjust the time based on what you see.
if your seeing a bump open sooner, a divot wait one more click.

[sutherpride59]

+1 to the above

However if you have to run your alloy or mold hot and youre impatient like I get sometimes with hollow point molds as hot as you have to run them just lightly touch the sprue to a wet sponge, JUST THE SPRUE. You dot want to touch the whole sprue plate or it will start to rust.

If im totally wrong on this correct me please but it's what's worked for me this far.

[hutch18414]

After getting used to my large "classroom" style clock right behind my towel or pan of water if water dropping I don't think I could cast without it any more. Consistency applied, average within .7 grs, on really good days .3 grs. Although I am finding that ambient air temp has more effect than I had realized.

[rr2241tx]

I find a noisy clock behind me is less distracting than one I can see. Also, lead:tin alloys are less prone to problems than alloys containing antimony, at least for me.

[gwpercle]

Bingo, you nailed your problem. Give it a few more seconds before cutting the sprue.
After filling I count slowly , 1001, 1002, 1003...usually at 1007 it's ready to open. Adjust count time as needed.
Gary

[Boolit_Head]

Set your phone to a web metronome at 60 beats per minute. That will help you set your pace.

https://www.google.com/search?q=metronome&ie=utf-8&oe=utf-8

[Hick]

If you have trouble using a clock, get a routine. I group my bullets in sets of 10 on the towel as i make them, so I can keep track of the count. then, (1) pour the mold, (2) slide the last set I dropped over to the correct pile, (3) pick up the sprue from the last set and toss it back into the pot (4) cut the sprue on this one. I do all four steps about as fast as is comfortable and the sprue is always frosty by then and cuts nice.

[MuthaFunk]

Wow. Thanks for all the great responses gents! I'll give the timers a shot!

I really like the metronome idea! I'm a weekend warrior musician and already have one!

[Shiloh]

Wait a few seconds longer and try again. Larger heavier bolts cool slower.

SHiloh

[denul]

I didn't believe that it would make a difference until I tried it, but a small electric fan directed across the sprue plate will definitely cool the sprue plate more quickly, and allow you to cut sooner. I have also used the wet sponge(in my case, wet cloth), mentioned above with good results, but you do have that risk of causing rust or discoloration in any susceptible areas, and there is more movement than there is in just tilting the mold into the airstream from the fan. With wet cooling, there is also the issue of moisture near the pot, which many casters will avoid at all cost.