Vanes or seams on cast bullets?

steve1147 · November 5, 2011, 04:12 PM

Searched the forums and couldn't find anything on this.
I cast my own bullets for .45acp, 38spl, 40s&w, etc. using a 92/4/4 alloy of lead/antimony/tin with Lee microgroove moulds.
My moulds are getting old and even when new left small lines on the bullet at the seam of the molds, now they're actually leaving small vanes on some bullets, which mostly disappear during lube tumbling, etc., but I know they're still there (although hardly noticeable) on some of them.
My question is, what effect do these have on the flight of the bullet?
Could their effect actually be noticeable or measureable on these small caliber handgun rounds at 10-25 yards or am I chasing ghosts?
Thanks! Steve W.

Vance · November 5, 2011, 04:27 PM

Any small line or groove, or "vane" can effect how a bullet travels. Accuracy will suffer.

GP100man · November 5, 2011, 06:20 PM

As long as they size away your fine , but if they start growing "wings" on the nose then it`s time to clean the mold good & clean & relube it with Bullshop`s Bull Plate Lube .

Also after cleaning look for worn battered alumilum in places it should`nt be .

I own many of Lee`s 2holer moulds & I started along time ago placeing em on a flat surface to close en ,it keeps em level & more square while they mate together.

The 6 cavitys have steel inserts for alignment & stand up to a little heavy handedness better ,but still need bull plate lube !

Short answer ,yes your chasin ghosts to a point .

The bullet will fly true as long as it`s balanced even an oval one.

steve1147 · November 7, 2011, 10:06 AM

Yup, I was picturing in my mind the bullet spiraling as it flies, but since doing the math, even with 38spl in my gp-100 at 900fps w/1:18" twist, that thang is spinning at 36,000rpm or 600rp/second. I'd guess if they would cause any spiral effect whatever, it would be very, very small at best!
Besides, all my guns are more accurate than I am!

chris in va · November 7, 2011, 10:33 AM

Clean the molds really well, especially around the pins. Mine get buildup after a while and won't close completely like you're experiencing.

If that doesn't work, keep in mind the molds are pretty inexpensive, around $25. The corner of my 9mm mold got rounded off a bit where the sprue plate attaches, so I simply put the plate in a vise and bent that corner a bit.

hornetguy · November 7, 2011, 10:54 AM

Vanes, fins... whatever you call them, it's all mold flash. This is caused by the mold faces not closing tight together. This is usually caused by a piece of lead spatter, or a dinged place on the face area of the mold. It could also be caused by some piece of debris in the locator/alignment pins.

Whatever the reason, it's not good. When your mold is flashing, you are molding out-of-round bullets. Granted, it might not be MUCH, but it is out-of-round.

Get some opti-visors, or a good magnifying glass... or, if you have access to it, a microscope, and inspect the faces of your mold. Carefully clean any debris or spatter from the mold, then try opening and closing it again. Keep after it until you are certain there is nothing hindering the mold from closing completely. Then mold some with it... the flash should be gone.

dahermit · November 7, 2011, 11:04 AM

Quote:

Vanes, fins... whatever you call them, it's all mold flash. This is caused by the mold faces not closing tight together.

But, there is the "fins" caused by too much pressure (lead forced out into vent lines), too much Tin, too hot. But they are usually not a problem, other than annoying...they can just be ignored and pressure (do not hold sprue hole tight against bottom pour spout), heat, technique adjusted to eliminate them.

hornetguy · November 7, 2011, 04:02 PM

yes, that is correct. I had forgotten about vent line flash.

I almost never run that hot, so I have seldom had that issue. I think the only time I saw it was when I tried to "pressure fill" a mold by holding it up tight against the spout when filling.

dahermit · November 7, 2011, 11:03 PM

When it (fins in vent lines), is caused by too much Tin in the alloy, the bullets are filled out beautifully, and the bullets themselves are perfect...it just is a waste of tin though. And Tin is getting hard to find and more expensive all the time.

IllinoisCoyoteHunter · November 9, 2011, 08:24 AM

Using straight WW alloy, I have never found the need for tin (not to hijack the thread)

.

dahermit · November 9, 2011, 10:58 AM

Quote:

Using straight WW alloy, I have never found the need for tin (not to hijack the thread) .

Back in the day that Linotype was plentiful, we would use it for our bullet casting. If the pot was set at the optimum temperature, the alloy would harden almost instantly in the iron molds, could be dropped without any waiting for sprue to harden for fear of smearing lead under the sprue plate. In short, there was no "mushy" stage in that alloy due to the proportion of tin to the lead and antimony, resulting in beautiful bullets cast a rapid pace. With wheel weights, due to the lack of Tin, there is a distinct and annoying "mushy" stage making it less than ideal for casting as is. However, techniques such as casting with two molds, etc. can compensate for that. Nevertheless, if a caster had the luxury of using straight Linotype, it is apparent why it was formulated as it was for casting type face characters in the printing industry. The qualities that made it ideal for printing, make it ideal for bullets also...we just cannot afford or find it anymore.

November 5, 2011, 04:12 PM	#1
steve1147 Senior Member Join Date: December 5, 2009 Location: Valles Mines, Missouri Posts: 142	Vanes or seams on cast bullets? Searched the forums and couldn't find anything on this. I cast my own bullets for .45acp, 38spl, 40s&w, etc. using a 92/4/4 alloy of lead/antimony/tin with Lee microgroove moulds. My moulds are getting old and even when new left small lines on the bullet at the seam of the molds, now they're actually leaving small vanes on some bullets, which mostly disappear during lube tumbling, etc., but I know they're still there (although hardly noticeable) on some of them. My question is, what effect do these have on the flight of the bullet? Could their effect actually be noticeable or measureable on these small caliber handgun rounds at 10-25 yards or am I chasing ghosts? Thanks! Steve W. __________________ Circa 1964: Rocky to Bullwinkle: "But that trick never works!" But Bullwinkle tries it anyway...again and again

November 5, 2011, 06:20 PM	#3
GP100man Senior Member Join Date: August 1, 2007 Location: Tabor City , NC. Posts: 1,969	As long as they size away your fine , but if they start growing "wings" on the nose then it`s time to clean the mold good & clean & relube it with Bullshop`s Bull Plate Lube . Also after cleaning look for worn battered alumilum in places it should`nt be . I own many of Lee`s 2holer moulds & I started along time ago placeing em on a flat surface to close en ,it keeps em level & more square while they mate together. The 6 cavitys have steel inserts for alignment & stand up to a little heavy handedness better ,but still need bull plate lube ! Short answer ,yes your chasin ghosts to a point . The bullet will fly true as long as it`s balanced even an oval one. __________________ GP100man

November 7, 2011, 10:06 AM	#4
steve1147 Senior Member Join Date: December 5, 2009 Location: Valles Mines, Missouri Posts: 142	Yup, I was picturing in my mind the bullet spiraling as it flies, but since doing the math, even with 38spl in my gp-100 at 900fps w/1:18" twist, that thang is spinning at 36,000rpm or 600rp/second. I'd guess if they would cause any spiral effect whatever, it would be very, very small at best! Besides, all my guns are more accurate than I am! __________________ Circa 1964: Rocky to Bullwinkle: "But that trick never works!" But Bullwinkle tries it anyway...again and again

November 7, 2011, 10:33 AM	#5
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	Clean the molds really well, especially around the pins. Mine get buildup after a while and won't close completely like you're experiencing. If that doesn't work, keep in mind the molds are pretty inexpensive, around $25. The corner of my 9mm mold got rounded off a bit where the sprue plate attaches, so I simply put the plate in a vise and bent that corner a bit. Last edited by chris in va; November 7, 2011 at 10:43 AM.

November 9, 2011, 08:24 AM	#10
IllinoisCoyoteHunter Senior Member Join Date: December 23, 2008 Location: Southern Illinois Posts: 1,527	Using straight WW alloy, I have never found the need for tin (not to hijack the thread) . __________________ ~~IllinoisCoyoteHunter~~ ~NRA LIFE MEMBER~ ~NRA CERTIFIED INSTRUCTOR~

November 5, 2011, 04:27 PM	#2
Vance Senior Member Join Date: January 16, 2011 Location: North Bend, OR Posts: 743	Any small line or groove, or "vane" can effect how a bullet travels. Accuracy will suffer.

November 7, 2011, 10:54 AM	#6
hornetguy Senior Member Join Date: January 14, 2011 Location: on the north side of DFW Posts: 970	Vanes, fins... whatever you call them, it's all mold flash. This is caused by the mold faces not closing tight together. This is usually caused by a piece of lead spatter, or a dinged place on the face area of the mold. It could also be caused by some piece of debris in the locator/alignment pins. Whatever the reason, it's not good. When your mold is flashing, you are molding out-of-round bullets. Granted, it might not be MUCH, but it is out-of-round. Get some opti-visors, or a good magnifying glass... or, if you have access to it, a microscope, and inspect the faces of your mold. Carefully clean any debris or spatter from the mold, then try opening and closing it again. Keep after it until you are certain there is nothing hindering the mold from closing completely. Then mold some with it... the flash should be gone.

November 7, 2011, 04:02 PM	#8
hornetguy Senior Member Join Date: January 14, 2011 Location: on the north side of DFW Posts: 970	yes, that is correct. I had forgotten about vent line flash. I almost never run that hot, so I have seldom had that issue. I think the only time I saw it was when I tried to "pressure fill" a mold by holding it up tight against the spout when filling.

November 7, 2011, 11:03 PM	#9
dahermit Senior Member Join Date: October 28, 2006 Location: South Central Michigan...near Posts: 6,501	When it (fins in vent lines), is caused by too much Tin in the alloy, the bullets are filled out beautifully, and the bullets themselves are perfect...it just is a waste of tin though. And Tin is getting hard to find and more expensive all the time.