PDA

View Full Version : Sprue Tail and Mold Complaints



iplaywithnoshoes
03-18-2017, 09:01 PM
I cast a few more 170gr from my 309-170 Lee mold today (My second casting session). What is starting to annoy me is that the bases are not perfectly flat and have a raised bump left after cutting the sprue. This makes it difficult to keep the checks on straight. Any ideas on what could be going on? The sprue plate doesn't seem to be loose and I am letting the alloy cool every 10 seconds or so. I'm casting with a thermometer as well.

Should I just not bother with Lee molds for rifle bullets? Haha. So far, even a mold that has oil or wax in it, has been easy to degrease, clean, and store with just a couple of castings and I'm afraid that nicer molds will be relatively cumbersome and expensive to deal with. :( So far, the most reliable one has been the 459-500-3R, casting consistent weights and diameters for me but my newest 309 molds (309-170 and 309-2300-5R have been so so).

shoe

country gent
03-18-2017, 09:46 PM
Try loosening the sprue plate a little, so it can sit flat and be at rest when closed. Over pour the moulds sprue plate to keep hot a little longer. and last try cutting just after it frosts over or just a few seconds, and besure to move the plate flat and straight no up force. It might help to lightly stone the bottom of the plate. Ive never tried it on a lee mould but on old steel moulds I have lightly touched the chamfer up with a chamfer tool to resharpen the cutting edge.

jsizemore
03-19-2017, 01:30 AM
Cut the sprue sooner.

BK7saum
03-19-2017, 01:54 AM
Yes, cut sprue just a bit after the sprue hardens. Letting it cook too much leaves a hump on the base when you cut the sprue.

44man
03-19-2017, 09:03 AM
Cut with little taps on the plate with a downward angle. You want to see little rings cut at the sprue. Don't smack the plate. Tension needs to be right or the plate will ride up. I don't like a loose plate or too tight either. Must sit flat is all.
I use pretty hard lead, WW's and if I cut too soon I get chunk outs but I never found it to harm accuracy. Nothing worse then a bump for a GC.

Mk42gunner
03-19-2017, 09:11 AM
I watch for the color change on the sprue, give it about a two count then twist the sprue plate with my hand. Fair warning, you want to have a glove on your hand when doing this.

This also allows me to catch the sprue and add it back to the pot before it cools.

Robert

w5pv
03-19-2017, 09:48 AM
I found on my sprue plate the cause was the mold had a dingle where the sprue plate stop and the mold met.After a period of use the stop would raise a little bump on the mold it self and that would raise the sprue plate enough that the base would smear on the bullet.This on a Lee 452 mold that is aluminum.I took a file and cut the bump back flat and that cured the problem for me

gwpercle
03-19-2017, 11:47 AM
It's not the mould. The sprue plate and top of mould must be flat, smooth and clean.
I've never had luck with a loose sprue plate, doing this requires putting pressue against the sprue to hold it against the block, while filling the mould ....any gaps = finned base. Loose plate also allows the plate to ride up when cutting sprue = bump on base. Snug up the plate, not as tight as you can get it , just snug enough so it stays in place. Cut the sprue in light taps (2 or 3 ), one big whack = bumps. Cut the sprue just after it freezes over ( I count to 5 ) so it will not smear .
Keep looking at top of block /underside of sprue plate , as soon as any smear is noticed STOP and clean both....it will just get worse and the boolits will get worse. Much easier to deal withb when it first happens
All of the above is related to Lee moulds, the sprue plate is a little TOO thin so they have to be treated carefully. A thick heavy plate is easier for beginners.
I bought Lee moulds when they first came out and have learned the tricks to casting with them. I have the same 170 grain mould and good boolits can be cast with it. An NOE will be a little easier because it has large blocks and a heavy sprue plate, but it will require proper lubrication and adjustment to work. I've seen new casters , my brother in law , ruin a mould because he wouldn't follow the simple directions.
Gary

fivefang
03-19-2017, 01:16 PM
Hi .44Man, years ago in the "Fouling Shot" (Cast Bullets)a mention about not striking the sprue plate, but resting the Mold on a firm surface and using a notched handle to shear the sprue with a bit of pressure toward the Mold, I personally give the sprue plate a slight tap after shearing & returning the sprue plate to cover the boolit base,Fivefang

John Boy
03-19-2017, 01:24 PM
the bases are not perfectly flat and have a raised bump left after cutting the sprue.
Corrections:
* Tighten the handle bolt just enough so when you flip the mold with your hand the plate swings open
* Your not letting the melt in the mold harden enough. Cut the sprue when the puddle is frosted, usually 5 - 10 seconds after the pout - bullet size dependent

popper
03-19-2017, 02:32 PM
Divots from base not solidified, tenets as the spruce has not solidified. Non flat bases as the plate cuts uneven, too loose or alloy really hardened.

44man
03-20-2017, 09:58 AM
I still get a chuckle over the spruce wood plates!
I know spell check sees no such word as sprue. Boolit gets the red squiggly line too.

44man
03-20-2017, 10:03 AM
Hi .44Man, years ago in the "Fouling Shot" (Cast Bullets)a mention about not striking the sprue plate, but resting the Mold on a firm surface and using a notched handle to shear the sprue with a bit of pressure toward the Mold, I personally give the sprue plate a slight tap after shearing & returning the sprue plate to cover the boolit base,Fivefang
That works but my plates are different and are full width out the front.191185