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different cast bullets (Read 7767 times)

dave_j Full Member Offline Posts: 246 Location: Nevada desert Joined: Jul 12^th, 2005	different cast bullets Apr 1^st, 2020 at 7:20pm	Print Post
	i have been casting bullets for nearly 45 years and think i can cast some decent bullets. i recently tried to cast some 30 cal bullets fora 308 winchester and went to a hard linotype mix. i usually cast at about 725 degrees for my schuetzen bullets. the harder bullets dont like that temp. i raised the temp to around 800 and they were frosty. dropped to 650 and they are better but dont want to jump out of the mold. can someone explain why the harder melt is so different thanks dave

	ah heck AA#9,4227,300MP, as long as it goes bang
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rgchristensen Frequent Elocutionist Offline Posts: 1088 Joined: Jan 2^nd, 2014	Re: different cast bullets Reply #1 - Apr 1^st, 2020 at 7:38pm	Print Post
	DAVE: A lot of things have changed.... The solidification takes place over a wider temperature range, and at a lower temperature. Since the bullets solidify at a lower temperature, the thermal contraction as they cool is less, so they don't shrink as much from the mould. That accounts for their sticking in the mould a little. Also, they solidify over a larger range of temperature. There are a batch of crystals in a puddle of liquid, and when they finally solidify, the liquid contracts into the center. This is the reason for the "frosty" bullets. So there are a LOT of things going on that you are not used to. Going to a lower temperature is the right thing to do, probably. Do you NEED a harder bullet? I have pretty much abandoned antimonial (ternary) alloys and stick with lead/tin and get along pretty good in the smokeless calibers at low (1400fps) velocities. CHRIS RGChristensen


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dave_j Full Member Offline Posts: 246 Location: Nevada desert Joined: Jul 12^th, 2005	Re: different cast bullets Reply #2 - Apr 1^st, 2020 at 7:45pm	Print Post
	thank you for the explanation. i started reading about the eutectic temperature and was a little apopelectic. your dissertation has made clear what was going on. i want to get a 2-300 yard load that will be accurate so the velocity could be somewhere around 1500 which is where a lot of our schuetzen rifles work thank you for the reply dave

	ah heck AA#9,4227,300MP, as long as it goes bang
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Longdistance1 Senior Forum Member Offline Posts: 429 Location: Amidon, ND Joined: Feb 11^th, 2013	Re: different cast bullets Reply #3 - Apr 1^st, 2020 at 8:34pm	Print Post
	I'll differ a bit, bullets with antimony need to be cast at a higher temp than lead-tin mix. They will be a little bigger in diameter as they don't shrink as much when cooling and a little tougher to get out of the mold, but if they arn't frosty they will have more voids in the base of the bullet when using a base pour mold. I'm a tightwad all my bullets are wheel weights plus added tin. LD1


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rgchristensen Frequent Elocutionist Offline Posts: 1088 Joined: Jan 2^nd, 2014	Re: different cast bullets Reply #4 - Apr 1^st, 2020 at 9:01pm	Print Post
	The reason that antimonial (ternary) bullets don't shrink as much is that they are cooling from a lower temperature than tin-lead (binary) bullets. The reason for "frosting" is that the solidifying bullets are a slush of crystals and molten metal. As they solidify, the liquid sucks to the center of the bullet, leaving a slightly porous pile of crystals behind. I am not saying that it is not possible to cast usable bullets of ternary alloys, but that it is fraught with more difficulties. Far easier to cast bullets of softer binary alloys, and in many (most?) cases they will do a fine job. CHRIS RGChristensen


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MikeK Participating Member Offline Posts: 34 Location: Northern Virginia Joined: Jul 21^st, 2018	Re: different cast bullets Reply #5 - Apr 1^st, 2020 at 9:05pm	Print Post
	Longdistance1 wrote on Apr 1^st, 2020 at 8:34pm: I'll differ a bit, bullets with antimony need to be cast at a higher temp than lead-tin mix. They will be a little bigger in diameter as they don't shrink as much when cooling and a little tougher to get out of the mold, but if they arn't frosty they will have more voids in the base of the bullet when using a base pour mold. I'm a tightwad all my bullets are wheel weights plus added tin. LD1 I've noticed the same frosty thing, casting straight wheel weights for my .40-65. They shoot very well with smokeless loads, though. Plus, I have over 200 lbs of wheel weight ingots.


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rgchristensen Frequent Elocutionist Offline Posts: 1088 Joined: Jan 2^nd, 2014	Re: different cast bullets Reply #6 - Apr 1^st, 2020 at 9:09pm	Print Post
	It can be instructive to look for cavities or voids inside bullets. Grab a bullet horizontally in a vise, a little below center. Shave it down with a sharp wood-chisel, and when you get near the center line, keep an eye out for cavities in the bullet. They are often found, ca 1 mm in diameter, and maybe 4-5 mm long, on the center-line of the bullet. Usually this means that your sprue plate is not the hottest part of the mould, as it MUST be, if you think about what is going on as the metal solidifies. CHRIS RGChristensen


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MikeK Participating Member Offline Posts: 34 Location: Northern Virginia Joined: Jul 21^st, 2018	Re: different cast bullets Reply #7 - Apr 1^st, 2020 at 9:10pm	Print Post
	Would the cavity show up as a weight variation?


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Longdistance1 Senior Forum Member Offline Posts: 429 Location: Amidon, ND Joined: Feb 11^th, 2013	Re: different cast bullets Reply #8 - Apr 1^st, 2020 at 9:29pm	Print Post
	Yes it will, from one with no cavity, but you can't tell where the cavity is! If you look at lineotype castings the voids are allways in the top part of casting, the bottom where the letters are is solid metal, the top usually has voids in it, if you snap it off, put in vice wack with hammer. That is why I cast hot with an antimony alloy to let the voids fill with molten metal, or let the air get heck out. LD1


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rgchristensen Frequent Elocutionist Offline Posts: 1088 Joined: Jan 2^nd, 2014	Re: different cast bullets Reply #9 - Apr 1^st, 2020 at 10:05pm	Print Post
	MikeK wrote on Apr 1^st, 2020 at 9:10pm: Would the cavity show up as a weight variation? Sure, this is the reason for weighing bullets. The weight variation itself doesn't make much difference, but it gives you a handle on your casting procedures. If some bullet weighs less than the maximum weight, it means that it is missing metal somewhere. Weighing is not so much quality control of the bullets, but a check on your casting technique. Best way to minimize cavities, is to keep the sprue plate the hottest part of the mould. If the sprue solidifies before the interior of the bullet, you WILL have a shrinkage cavity. Fortunately, they are almost always in the center of the bullet, where they make the least unbalance. CHRIS RGChristensen


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Cbashooter Frequent Elocutionist Offline Posts: 1568 Location: Eastern Wa. Joined: Mar 31^st, 2018	Re: different cast bullets Reply #10 - Apr 1^st, 2020 at 10:39pm	Print Post
	My dad was a typesetter and when I started casting bullets 35 years ago all I had was a linotype and and that's all I use for the first 15 to 20 years. I used it and handguns and bottleneck cartridge loads and 45-70 smokeless loads with great luck. Casting at a lower temperature works for me. A hard type metal bullet properly fitting the throat in a benchrest type bolt action or single-shot rifle can shoot sub half minute and it's pretty competitive with schuetzen rifles in CBA matches and similar scores are made. Most of my plinking is with 30 caliber rifles .I use mostly range scrap and wheel weight with a brinell hardness of about 15. minute to minute and a half is not that hard to get out to 200 yards without sorting bullets are doing anything crazy.


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marlinguy Frequent Elocutionist Offline Ballards may be weaker, but they sure are neater! Posts: 16072 Location: Oregon Joined: Feb 2^nd, 2009	Re: different cast bullets Reply #11 - Apr 2^nd, 2020 at 11:53am	Print Post
	Does it really matter where the voids are in a cast bullet? That is to say if it has a void anywhere it will result in a bad bullet that should be tossed back in the pot. Simply weighing bullets during sorting should eliminate lighter bullets outside the tolerances you choose, without worrying about where the void is.

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JackHughs Oldtimer Offline Posts: 657 Location: Riverbank Joined: Sep 27^th, 2008	Re: different cast bullets Reply #12 - Apr 2^nd, 2020 at 1:20pm	Print Post
	dave_j wrote on Apr 1^st, 2020 at 7:20pm: i have been casting bullets for nearly 45 years and think i can cast some decent bullets. i recently tried to cast some 30 cal bullets fora 308 winchester and went to a hard linotype mix. i usually cast at about 725 degrees for my schuetzen bullets. the harder bullets dont like that temp. i raised the temp to around 800 and they were frosty. dropped to 650 and they are better but dont want to jump out of the mold. can someone explain why the harder melt is so different thanks dave You mention a "linotype mix." Straight Linotype makes for great bullets for fixed ammunition and drops beautiful bullets from a good mould at about 600 degrees. Linotype mixed with anything creates mystery metal that may be good for volume-cast pistol bullets but will drive you nuts trying to make quality rifle bullets. If you want to try harder bullets for breech seating, just use a quality 1/16 alloy. If you want really hard bullets for fixed ammo, use straight Linotype. JackHughs

	The best lack all conviction, while the worst Are full of passionate intensity. W.B. Yeats
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westerner Frequent Elocutionist Offline deleted posts and threads record holder. Posts: 11451 Location: Why, out West of course Joined: May 29^th, 2006	Re: different cast bullets Reply #13 - Apr 3^rd, 2020 at 6:09am	Print Post
	JackHughs wrote on Apr 2^nd, 2020 at 1:20pm: dave_j wrote on Apr 1^st, 2020 at 7:20pm: i have been casting bullets for nearly 45 years and think i can cast some decent bullets. i recently tried to cast some 30 cal bullets fora 308 winchester and went to a hard linotype mix. i usually cast at about 725 degrees for my schuetzen bullets. the harder bullets dont like that temp. i raised the temp to around 800 and they were frosty. dropped to 650 and they are better but dont want to jump out of the mold. can someone explain why the harder melt is so different thanks dave You mention a "linotype mix." Straight Linotype makes for great bullets for fixed ammunition and drops beautiful bullets from a good mould at about 600 degrees. Linotype mixed with anything creates mystery metal that may be good for volume-cast pistol bullets but will drive you nuts trying to make quality rifle bullets. If you want to try harder bullets for breech seating, just use a quality 1/16 alloy. If you want really hard bullets for fixed ammo, use straight Linotype. JackHughs Are you sure about that, Jack? Half lino half wheel weights makes a very hard consistent alloy for me. Easy to cast, no mystery. Jack, what mystery issues have you had with your alloy? What alloy is the bad one?

	A blind squirrel runs into a tree every once in a while.
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40_Rod Frequent Elocutionist Offline Extremism in the persuit of accuracy is not a vice Posts: 4285 Location: Knoxville, TN Joined: Apr 20^th, 2004	Re: different cast bullets Reply #14 - Apr 3^rd, 2020 at 10:06am	Print Post
	Im with Jack on this one. My problem with Lino and other antimony rich alloys is that as they harden much slower than lead/tin they leave voids inside the metal as they cool. This is a phomina that Charlie Dell noted with his bullets and said that they were in all bullets so I recreated his experiment with my (at that time) 25 : 1 bullets. I found no voids. when I told that to Charlie he had to see for himself so I took a couple of bullets at random from my boxes and we went to Charlie's shop grabbed a few of his and proceeded to shave bullets down. We found voids near the center of his and in mine except for one with a pinhole none of mine. About 6 months later he told me he had gone back to lead tin as he was trying to find an alloy that was stable and with all of his experimentsthey got harder over time. So given the voids problem and that he couldn't solve the stability problem he went back to lead/tin. 40 Rod


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