Sprue

[mag_01]

:coffee: ---Return the sprue to the pot while casting or not ?---Pros or Cons---And if you do return the sprue to the pot can that little bit of lead really affect the quality of your casting ?------:castmine:

[beagle]

Here's another one of those hairy topics and I'll probably get yelled at.

In theory, it will change the alloy a very small amount.

If you're all hung up on alloys and precise BHN, don't do it.

I'm not that hung up and I shovel them back in and flux and my bullets perform up to my expectations.

So, guess what I'm saying, its your call and depends on how precise you want to get with this stuff.

Kind of falls into the category of pole vauling over mouse turds./beagle

[floodgate]

mag_01, Beagle:

I don't see how tossing a fresh-cut sprue back into a pot of the same alloy you just cast with could change the mix at all! I actually drop mine back in every 10 or 12 castings. We have beaten the old saw about alloys separating out to death; at any reasonable casting temperature, tin, lead and antimony stay fully mixed, especially with a bottom-pour pot with a layer of litty-kitter or sawdust to prevent any possibility of differential oxidation.

floodgate

[STP]

If you have the primers/caps and the powder to use, try it both ways. I ordinarily don`t fret the difference unless I`m casting the heavyweight .45 and .50`s for BP using pure lead with added tin. The higher temps and the concerns of tin loss will change my habits in a 10lb pot. If the mould is fussy in terms of fillout, I`ll toss the sprue right back in the pot just to make me feel better even with a 20lb pot. Does it help?...Dunno, I cast for BP friends, as I don`t shoot them myself.
Hardness testing with an early Redding BHN testing instrument fails to show any measurable difference.
"Uncle" Harvey Donaldson said to arrange the casts in sequence, and shoot them in order as cast. His advice seems difficult to refute, based on his background.
With typical WW alloys, I`d doubt it would matter...a Ransom rest may prove otherwise. But a rifle/pistola held in the usual manner is a difficult test method at best.
I know that I will follow `ol Harvey`s advice when the Maynard finally arrives here.

[Phil]

I always throw them back in, in no particular sequence. My most accurate cast bullet gun is an 8.15x46R. I breech seat the bullets which are made of 20 parts lead, one part tin. During a three day tournament I fired about 90 five shot groups in competition. This doesn't count practice groups and sighters. So over the three days I fired over five hundred rounds or probably one hundred seventy rounds per day minimum, groups fired for record, sighters, warmers, practice groups, all that. The rifle was cleaned at the end of each day only. The aggregate of the ninety groups fired for record was .387 moa. The smallest group was the last group fired at the end of a day and measured .162 moa.

The bullets were not fired in order of casting, from the mold I just put them in a pile. They were not weighed or oriented. They were cast in a nose pour mold that Richard Hoch made for me. A magnificient mold I might add.

So, from my experience, I'll just keep doing what I've been doing. I know Pope and lots of those guys always shot the bullets in the order they were cast but I wonder if even they knew why they were doing it way. I have a couple of theories about why they followed that procedure but thats just what they are, theories.

I always use an inch or so of kitty litter over the melt and monitor the temperature with a pyrometer. Use the same procedure whether I'm using 20/1, WW, WW+Lino, straight Lino, whatever. Works for me.

Just my $.02 and probably worth less than that,

Phil

[LAH]

I stand while casting with the pour spout 'bout shoulder level. I cut my sprue and it falls into a bucket. I do it this way for ease of movement. While I do add alloy while casting it's pre heated 8 lb bars. I normally use the sprue for my initial melt. Just the way I do it..........Creeker

[Hunter]

When I cut the sprue it goes directly in the pot just be sure to do it easy. Splashing molten lead is not good. So far I get a constant 19.3 bhn from my Lee hardness tester.
I just cast for .45 ACP and .357 magnum and my method does not seem to make enough difference for me to tell but I am still new at this.

[NVcurmudgeon]

I run my twelve lb. ladle pot about 750F. Every fifteen or twenty casts I add a pre-warmed pound ingot and a small handful of still warm sprue. I believe this helps to keep temperature close to uniform. My rifle boolits are nearly all something I can be very proud of, and the pistol boolits are more than adequate for my wobbles.

[grouch]

I don't do it because of the lead splashing onto the mold blocks. I seem more likely to get a spatter between the blocks, causing a larger no. of overweight reject bullets.

[Sven Dufva]

I cant find any problems to put sprue back in pot if you dont put so mutch so the temp goes down to mutch.
I doit all the time.

[John Boy]

Recent casting experience using a digital thermometer in a 10# bottom pour pot has shown me that an average sprue from a 500gr bullet, reduces the pot temperature aproximately 5 degrees for each sprue put back into the melt.

I cast to plus or minus 0.5grs and to maintain this variance, constant pot temperature is critical dependent on the mold and the bullet weight

All my sprues go in a pile and when the pot temperature starts to rise, I throw 1 or 2 sprues back in to bring the temperature back down to the constant temperature.

As for different Bhn's in the same batch, putting sprues back in ... I've found no difference with my method. This is based on measuring several bullets for a given batch. If there is a difference if a handful of sprues are returned to the melt ... can't respond because I put them back at the end of the casting session and then make an small ingot. This ingot is then part of the same alloy for the next casting session

[georgeld]

Put my sprues back in soon as cut off the pour unless they get dropped
on the dirt shop floor, or in the water bucket, not many of them don't get put back in the pot right away.
I feel since they are hot it helps keep the pot full longer.

I sit in a chair with the pot on a wooden bench about knee level and bucket next to my leg. Seems to help my back last longer before it starts hurting too bad.

When ever the melt gets below 700 on the Lyman thermometer from adding preheated ingots. I'll do a quick inspection of the bullets cast since the last time it was done. When ever thats done, IF the melt hardens on top, I'll put the rejects if any in the pot too. IF it's still liquid, they go into a can for later remelting.
Seems to work ok for me this way. I'm not too particular except on the heat, I stop casting whenever the melt drops below 700.

Since I just got this a few yrs ago I've found there's much less rejects by keeping it hot than when I let it get colder than 700.

Until I got it, was running 10-20% rejects. Hotter melt sure helped my production and results a lot. One of the best investments I've made for casting.

I don't keep floaters on my melt, I do keep it within a pound or two of being full. Except when I'm ready to stop, then I'll keep running it down til less than half, then turn the heat off and cast til the spout freezes up.

[Ricochet]

The way I see it, the main effect of returning sprues to the pot is on melt temperature, not composition. If you pile up a bunch and then return them it'll have a lot more effect than regularly dropping the sprue from each cast, which really shouldn't affect it if it's staying in rhythm with casting. Lead splash from dropping a sprue can make the sprue plate jam or rise and give smeared bases, but the real trouble comes when you open the blocks to drop reject boolits back into the pot and get lead between the blocks, accidentally "Beagling." They need to be dropped into a separate container, then dumped in the pot.

[felix]

The pot should have a thick layer of a blanket material, like kitty litter, borax, wood ashes, etc. During a coffee break you can mix in the sprues a'la' Ricochet if so desired. ... felix

[tomf52]

I've been casting on and off for forty years and have always dropped the sprue back into the pot as I cut them off the mold. Have had no problems with this technique.

[sundog]

If any of you, your equipment, and your ammo and boolits are THAT good (and the conditions you shoot in) that you can tell if the sprue has been thrown back in while casting..., well, I'll just sit and spectate any time you shoot as you obviously have alot to teach me that I did not learn along the way!

I run my pot pretty hot when I cast, almost always with a layer of wood ash. Ever four or seven throws I throw the sprues back in, and they go molten immediately. Can't tell a difference in temp as I am always waiting on the sprue anyway. My match boolits are among the world's finest. How do I know? Because they satisfy ME. Sorry if that sounds a little snobbish, but over the years I've more than a few gargantuan failures along with one or two flowering successes. Most of what I know in boolit casting, and life, I've learned from the former. sundog

[felix]

Variables other than a few lousy sprues get into the way of any casting material to make the material go sour. ... felix