Understanding "Draw Down"?

[BrushBuster]

I've been enjoying my efforts at trying to creat the perfect Soft-nose bullet, utilizing the info. provided by BruceB and others. Definately making progress here, and am now at the testing stage of these specialized hunting bullets. However, during the casting process there was one recurring problem that accounted for 100% of all my rejects; I experienced poor fillout of the bullet bases, some so bad that they simply could not accept a gas-check! Since I do not have this problem when casting normally, I could only assume it has something to do with the extra heat and cooling time involved in this process.

In attempting to correct this, I decided to cool the mold with a damp towel only from the mold base, and leave the top or sprue plate area air cooled only. I felt that because of the high mold heat involved, the draw down that occurs with normal mold temperatures and sprue formation was not happening and that the bases of the bullet were being "starved" by a sprue that had hardened prematurely. Cooling the mold base only helped, but the problem of poor bullet base fill-out though improved, still existed. Here again, I'm thinking that the time involved in cooling down the bullet results in a sprue hardening prematurely whether cooled by air or a damp cloth.

Other efforts at correcting this condition have included increasing the tin content, and air cooling only before dropping the bullet, but these have not helped. Perhaps I just really don't understand "draw down", or am I looking in the wrong place for a solution? :confused: Any suggestions?

Thanks,
BrushBuster

[robertbank]

Seems to me you are on the right track. I too am about to attempt to make some soft nose bullets using the information provided.

Take Care

Bob

[44man]

Exactly what happened to me! I could not get a good base. Also the boolit showed a mixing of alloys so the entire boolit tested the same hardness. The temperatures required are just too high for good boolits.
There might be a way to do it but I have not tried it. Pour the nose and let it get solid, then pour the base and let it get solid. Then put the mould in the lead until the sprue just starts to melt. The mould would have to get back down to about 500 degrees before casting another boolit. We are talking a lot of time per boolit!

[7br]

My level of frustration was reached and I decided that a pure lead slug would work for deer at revolver velocities. Works for the muzzleloaders and if accuracy is acceptable a 75 yards, don't see why they wouldn't work in my .42

[OLPDon]

Was following the board on making soft nose cast's and as most casters are they build better mouse traps. Seeing in NJ shotgun slugs and muzzle loaders are all that is allowed for deer with firearms, didn't try making soft nose cast. I do have plenty of molds as I find myself casting more then shooting due to other endevers.
I have to admit that I enjoy making cast as much or maybe more then the Hunting part for reasons many can relate to (1. age, 2. Don't like getting up early Morn. 3. draging that buck out "ouch") But I digress.

I have 2 RCBS Pro Melts one set up for Pure Lead and other for Hard Cast. I have a 32 winspl that send the Lead to target like a dream and it not because I am expert reloader / or caster. At one time when eyes were good ( longer then I can remember) was expert shooter small bore prone.

Was thinking of getting the mold up to temp by casting with RCBS Pro Melt #1 Hard Cast
RCBS Pro Melt #2 (pure lead) flow setting to a trickle practice pouring nose to get rhythm going to try to get a close to same amount of lead.
I understand there would be a weight differance in the bullet, make enough bullets and some have to mach by chance.

I think a what is more important is getting the nose pour to be as level as possible
so I will set up a level block for a rest leveling problem solved there. As soon as nose is poured move over to RCBS #1 and fill mold as usual and drop in water bucket as I always do. Hopefuly they will fill out well, will keep you informed.
Have to be honest Middle Name should be (Roundtooit)
Kindly give me feed back on what you think.

Better Mouse Traps and Better Boolits

[Four Fingers of Death]

Would tapping the mould on a softish piece of timber like pine before quickly dropping in the nose help?

Maybe this is a job for two people, one on each ladle.

MIck.

[robertbank]

BrushBuster

Thanks for the email and your notes. I am going to go with your suggestion and use the fishing sinker lead I have and try casting some 311041 bullets for my 30-30 and see how they work. I'll Let you know how I make out.

Take care


Bob

[45 2.1]

When you all get tired of trying to cast soft noses, try this: Use an alloy of 1/2 wheelweights and 1/2 very soft lead, cast your boolits out of this alloy, water drop those boolits right out of the mold, wait two weeks for them to harden, gas check and lube, then load them and try some expansion tests, then report what results you got. This is good to about 2000 fps in small calibers and 2200 fps in larger calibers.

[BrushBuster]

I didn't want to give the impression that I'm not succeeding with soft-nose boolits, only that I would like to cut my reject rate down (approx. 25%) as this is a time consuming process. I just wish I could explain the poor base fillout problem that occurs sporadically. There must be a key to it

Keeping the mold level and static during the cool-down period might also help because the boolit is solidifying at different rates from two directions. In any event, I have a number of good looking soft-nose boolits that are ready to submit to testing. My goal is a hard shanked boolit that will expand fully at the nose and still provide deep penetration (Nosler-like). To begin with, I have allotted 100 grains of pure lead to a 260 grain boolit. Tests may indicate this is a higher ratio than optimum, but nobody said this was gonna be easy!

45 2.1, that does sound like an interesting formula. I do all my cast boolit shooting in those speed ranges, and I'm sure it would work in my .35 Rem., but my .348 gets quite inaccurate if the shank hardness is less than BHN-18. I'll continue to grope along with these softies for now, but eventually might come around to your way of thinking. Another winter project!

[44man]

45 2.1 has the easiest way. A softer alloy with enough weight is a lot easier then making a two part boolit. I never had any problems with pure lead in a muzzle loader going all the way through deer because the boolits or balls were heavy enough.
Even my .45 Ruger old army with a round ball shoots all the way through deer. Smashes bone and deer don't go far, one went one jump and died. Thing kills faster then my .475! It just doesn't have the accuracy and range of my other handguns.

[Nrut]

When you all get tired of trying to cast soft noses, try this: Use an alloy of 1/2 wheelweights and 1/2 very soft lead, cast your boolits out of this alloy, water drop those boolits right out of the mold, wait two weeks for them to harden, gas check and lube, then load them and try some expansion tests, then report what results you got. This is good to about 2000 fps in small calibers and 2200 fps in larger calibers.

Well 45 2.1 thats exactly what I came out with while trying to cast these softnoses.....they looked great as you can see the color change where the lead and WW meet so I thought I had success....No soap!....I measured the softnoses I cast about two weeks ago and the ACWW bullets I cast the same day and they both came out just over 11bhn on both ends of the bullets :roll:... But thats ok as they where 1/2 WW and 1/2 roofing lead.....I got the type of bullets you suggested to make only it took me a lot longer to make them..........[smilie=1:

[45 2.1]

The trick is that if you air cooled the alloy, it would be about 8 BHN which is good for hunting as it expands readily. But, you need to water drop it which gives a hardness of about 18-19 BHN after a two week wait. The boolit is hard enough to do most loads and it expands easily in an animal or otherwise. No muss or fuss.

[Bass Ackward]

The trick is that if you air cooled the alloy, it would be about 8 BHN which is good for hunting as it expands readily. But, you need to water drop it which gives a hardness of about 18-19 BHN after a two week wait. The boolit is hard enough to do most loads and it expands easily in an animal or otherwise. No muss or fuss.


Yea. One more advantage is that the mix dilutes down the antimony and arsenic. So with the hardness, you get all or nothing on heat treatment. Translation: it doesn't heat treat very well in an oven as you have a VERY narrow temperature range to develop hardness and must be almost to the point of melting which means smaller batches of bullets. But there is an advantage to this.

If you do anything at all to the nose that develops heat or works the metal, like drilling a hollow point, the mix reverts back to its old self in that area. Same with annealing. Much less heat needed to get back to SOFT than with normal HTWW .

[44man]

Yep, just make softer boolits for expansion. I use a lot of hard stuff for accuracy but the extreme accuracy is not needed for deer at normal hunting ranges. Even if the boolits lead the bore a little, so what! A few shots on deer amounts to nothing. The only thing I recommend is to use a heavy boolit for penetration.
Bass has been right all along and a lot of us still think we need the hard shank.
This season I am going 50-50 WW's and pure lead and will post hunting results. My .475 doesn't need it because of the HUGE meplat but my 45-70 does. I never made a WFN mould for it yet.
One very strange thing after shooting a pile of deer with all of my revolvers is that the .44 kills faster with more blood then the same size meplat with a faster boolit. Does slower kill better? The .45 Colt kills faster then the same weight boolit in the 45-70. (Same meplat.)

[Nrut]

A friend of mine annealed some ACWW last May and so far they have remained around 9 BHN....so if you don't have much pure lead to mix with and you are looking for that range of hardness you might try it.......

[Bass Ackward]

One very strange thing after shooting a pile of deer with all of my revolvers is that the .44 kills faster with more blood then the same size meplat with a faster boolit. Does slower kill better? The .45 Colt kills faster then the same weight boolit in the 45-70. (Same meplat.)


44ma,

From my experience, bleed out was always faster and more pronounced with a 44 in a handgun configuration than a rifle. Now, the rifle could produce those TV colapses every once in awhile if you hit a nerve, but again, bleed out was always more severe with the handgun unless you cut the meplat size a little. This is on deer by the way. I would sumise the results will flip as game mass is increased.

[357maximum]

Go back up and read 45.2.1's posts, my 50/50 alloy came out at 20.9 bhn, but did it ever work, oh boy did it ever work. The best part is that it works for accuracy, and expansion, a win/win situation...

Thanks BOB