Home Forums Reloading Bullet Casting I've noticed.....

that when my molds get hot the bullets sometime don'e fill out as well and it becomes more difficult to get good bullets. I'm using a Lee 20 pound bottom pour and the spout doesn't seem to fit the sprue on my Accurate molds very well. Some time I get leakage that will block the next fill hole or get molten lead all over everything. Would a RCBS furnace solve a lot of my problems? I suspect I get my mold too hot when casting and need to slow down a bit.

Sounds more like a molten lead dispensation issue than the mold being too hot, Mickey. It sounds like you're putting the mold up against the furnace spout. If so, perhaps you are trapping air in the mold. I hold the mold about an inch below the spout which gives air a chance to escape as the cavity fills. Just a WAG, from out here in internet-land!

yeah! normally if the molds too hot you get whiskering, not a problem filling the mold, if its not filling out the alloys too cold or theres oil or some contaminate in the mold,IF the mold whiskers into the seams of the mold where the air normally escapes IT Could be: the alloys too hot, the alloys got too much tin,(more than about 6%) you have too much melt pressure because your not pouring, and allowing the sprue to form and cool on the cut off plate, your placing the mold directly on the furnace pour spout.


http://www.n-ssa.org/NORTHWEST/Casting%20Bullets.htm

http://www.youtube.com/watch?v=C2aQpVKiCN8

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.htm

http://www.lasc.us/ArticlesFryxell.htm

I do hold the mold against the spout. I've tried it both ways and the base seems to fill out better that way. If I hold it off I get a lot of bases that have a slightly rounded edge. Will this affect the performance of a fire bullet?

Both of my Accurate molds require that I hold the dipper up against the sprue plate to get good square bases. If I free pour into the holes they mostly end up rounded, so holding yours up to the bottom spout is probably the right way.

Molds are certainly individualistic. My LBT molds all liked to have the dipper held about 1/4 to 1/2 inch above the cavity and free poured to get a good fill. Another Lyman 2 cavity .30 caliber mold needs to have the dipper hard up against the sprue plate.

I know folks love their bottom pours, but have you tried a dipper? I've read articles back and forth on this, but the concensus of the articles and my own experience seem to indicate that while you can get a higher production rate with a bottom pour, you get a higher percentage of good bullets (keepers) with a dipper. So I switched to a dipper for everything.

On the bases, my instinct tells me that as long as the base is concentric it should be okay. After all a boat tail is not a square base (except where it concentrically meets the full diameter portion) and they shoot pretty straight. But - I'd still want square base bullets to be square, if for no other reason than to be as alike to the other bullets as possible.



Hopefully there might be a partial answer to your question among all that preceding blather...

Jim,
I prefer the square bases but upon reflection I have to admit that the bevel base wadcutter doesn't have a square base like we're describing. However, On occasion I get some bases that are filled on the edges but have a small 'trough' in the base of the bullet and some have a cavity almost in the center of the bullet. Is that a characteristic of the Accurate mold?

I may try the dipper. I finally realized that you can change them from right handed to left handed so that does away with my objection to them.

Thanks for your input and advice.

If your mold gets too hot, your bullets won't be shiney but will appear frosted. Also you may need to slow down the flow rate out of your spout if it is splashing into the next opening. I would say slow the flow and pour with the sprue plate about 1/2 inch under the spout. And to answer your question, if you are planning on continuing to bottom pour, then the RCBS or Lyman furnaces will make life easier. I like a lot of Lee's products but not their bottom pour furnaces; they leak! They do make a nice little 20 lb dipper pot though. Sorry I rambled a little, just me......

Adjustable flow is a must in a bottom pour, simply due to varying mould/bullet volume and also the amount of alloy weight in the pot.
Then using similar makes and mould/bullet volumes you can cast a pile of minimal reject bullets, gradually increasing flow as the alloy weight in the pot lessens.

Using a brass 22 mould with a favorite aluminum 45/70 mould doesn't make for enjoyable casting!

I smashed the last LEE bottom pour pot I had. Didn't even make a decent soft nose alloy pot. Its a glorified beer can with a hole for a nozzle and a nail for a spout plug, IMO.

I have the Lyman and an RCBS; LOVE the RCBS and the Lyman is perfectly adequate. I have also heard good things about Magmas bottom pour pot.

Some folks cast for economy and enjoyable volume, some folks cast to build a bullet as good or better than they can buy.

Nothing wrong with either choice.

I got a pm that suggested the sprue plate was too tight. I remember tightening it some it wouldn't flop. Probably a mistake so I'll loosen it up a tad. A dipper was suggested but I like the furnace. May spring for an RCBS. The Lee bottom pour is better than the 'Leaky Lee' that I had but I still don't think it's optimal. Thanks, guys.

My experience is that square bases tend to be more uniform and I believe more accurate - the general opinion I see is that bevel bases do well with progressive loading for high volume shooters but square bases are still more accurate. If I wanted bevel bases I'd want a bevel base mold rather than expecting a not quite filled out mold to be uniform. For my own bulls eye shooting with 4 cavity molds my best product included bullets weighed the same to the nearest tenth grain weight from multi-cavity molds. I had no trouble producing pistol bullets that measured and weighed the same from multi-cavity molds.

IMHO the trough or cavity is a result of insufficient lead which may be related to a tight sprue plate or venting issues and not bleeding air well. I believe the alloy shrinks in cooling and needs enough hot alloy above the sprue plate to fill out the shrinking alloy in the bullet - maybe a cutting issue dragging lead out of the bullet base but I'd be surprised. Maybe a bigger hole? For molds that have a trough joining the holes some have suggested going ahead and filling the trough - this may vary with how thick the sprue plate is but a more complete Hershey's kisses sprue is better than an M&M sprue.

My own practice was a bottom pour 10 pound Lyman pot with a substantial drop through a fairly large hole in the sprue plate to fill the mold and some left on top then move to the next hole - eyeballing the lineup of sprue hole and spout was tedious. Lead level kept high in the pot with prepared ingots.

I have the Lee Pro 4-20 melter and find that my Lee mold (just starting and only have 230 swc mold) fills much better when placing it against the nipple. I have learned to drag the mold off the spout in order to get an adequate sprue puddle. On my melter, with straight wheel weight I get nice slightly frosty bullets at about the 3.5 - 3.75 setting.

If you're casting with WW alloy or range lead but sure you're hot enough. I like 'bout 750 degrees & a mould hot enough the bullets are a dull grey. The moulds I use cast better with a slightly loose spure plate.

Several years ago I did a poll with my customers & about 85% or 90% like the RCBS pot better than the Lyman. If you can afford the RCBS then by all means go for it.

Sprue plate should fall free when the mold is turned on its side. NO TIGHTER.

Also, add a little tin and the fill out problems will go away and you will be able to cast at a lower temp. If you have to hold the mold against the drain tube, you have something wrong. Also pour a big puddle on top.

Tomme Boy, does that apply to the aluminum molds too?? Mine is pretty darn snug.

To all: I loosened up the sprue plate screw and it solved all the problems I was having. Can't thank all of you enough. It's not Accurate Mold's fault; I tightened up the sprue plate when I got the mould. Just another of my misteaks.

My thanks to all of you.

All's well that ends well! Sorry, I never gave sprue plate tightness a thought. Just goes to show that the word 'assume' makes an ass out of 'u' and 'me'. (Especially me!)

Basically, air needs to be displaced as lead flows in or voids are the result. Air escapes via the vent lines on a mold block, or out from under the sprue plate, or out through the sprue hole itself if lead is flowing through it in a small enough stream to allow air to escape around it. My mistake was assuming that the two main venting systems were functioning but that the flow of lead was too much for them to handle the displaced air, necessitating the sprue hole itself needing to take up the slack- hence my advice re: not pressing the sprue plate against the spout. (Sorry for the wordiness too.)

You guy's answered my question before I even asked it , about the sprue plate. I tightened mine up thinking it was to loose.

Got on the fire and there it was just like perfect timing.

My first try at smokeless slugs and I cast about 350 and kept 92 good ones. learning curves are tough some times.

Thanks for all of the help

As your alloy cools it will draw more lead into the cavity. For that reason don't be afraid to overflow the sprue plate a bit. Filling "just enough" to top off the cavity will contribute to the rounded bases you mentioned.

This, if I may say so, is a good and informative thread for new bullet casters AND us old guys who have been casting for years. Thanks guys.....