pour speed- big bullets

[3584ELK]

:?

I have an LBT casting pot, and up till yesterday, only cast bullets out of a 309-160R Lee mould.  

Having received a new RCBS 35 caliber mould for 200 gr. rifle bullets, I found that even with the pot maxed out on temp, and pouring as fast as the pot would go left me with "cold" bullets.  It looked to me that not only was the pot not pouring fast enough, but the sprue was tiny for such a big bullet.  

Just wondering if you fella's have any experience with this, and or recommendations?

[jhalcott]

sounds more like the mold needs cleaning. I cast 250 grain 358's and even 420 grain 458's(some times they get frosty) and don't get wrinkles. My pot is a Lee 20 pounder,seldom run on high.

[Longcruise]

Your mold may be running a bit cool also.

I pressure pour when using ladle or pot by pressing the pour spout of the ladle or the pot onto the sprue and then backing off just a bit to pile a bit of lead on top of the sprue cutter.

[John Traveler1]

Many years ago, when I was new at bullet casting, I started using BIG 4 and 6 cavity molds to increase production for competition pistol shooting.  I got poor results like you described: wrinkles, incomplete fillout, and difficulty maintaining block at temperature.  It was simpler to use the 1 and 2 cavity molds.  

A machinist friend borrowed the 4 and 6 cavity molds and kindly made hardened aircraft aluminum sprue plates for them, with much larger holes and sprues.  The problems went away!  He explained that the big mold blocks were designed for production work, but they handicapped themselves with the standard sprue plates and holes.  

It turns out he modified most of his bullet molds with the aluminum sprue plates and pour holes that were 2x factory standard.  The aluminum plates have the added benefit of not sticking to lead.


HTH
John

[3584ELK]

great advice! I should have clarified that it is the sprue PLATE that has too small a hole.  I can see you figured that out, though...

I tend to think I could use some beeswax, a sharp countersink, and open the existing sprue holes up.  This particular RCBS mould has two cavities.   I am not deriding the mould, as I tend to blame the furnace for not pouring faster.  If I had to guess, I would peg the stream diameter at around 3/32" or maybe less.  I will look at it for blockage this weekend and report back.  

Thanks for the tips!

[w30wcf]

3584ELK,

In my experience I have been using smaller sprue hole sizes with complete success using w.w., Lyman #2 or Linotype alloys.  One can make excellent bullets with smaller holed sprue plates.

Interestingly they did not work as well with lead/ tin alloys nor monotype.

What alloy are you using?

I would suggest that you try pre heating  your mold to 400-450 degrees in an oven.  I have a small toaster oven that I use for just that purpose.
When I turn the pot on, I start preheating the mold(s) I am going to use. When the pot is up to temperature, the preheated mold(s) are too.

The first bullets cast are "match grade"  using this method and with the sprue plate already hot, the metal flows freely and does not freeze off in the sprue hole until the bullet cavity is filled.

Good Luck,
w30wcf

[Haywire Haywood]

I was having that problem with 458 molds.  Dan at Mountain Molds told me to get a ladel and drill the spout out to 3/16 to fill the mold as quickly as possible.  It helped a lot. Also, clean that mold out really well.  Read my post titled "Rusty" down the line a bit.  That helped me out more than anything.

Ian

[w30wcf]

3584ELK,

If you do open the sprue hole diameter, I would suggest that you first try a 1/8" sprue hole for your .35 caliber bullet.  Over the years in experimenting with sprue hole diameters, I have found that a sprue hole diameter that is about 1/3 the diameter of the bullet seems ideal and delivers excellent results both in casting, obtaining minimal bullet weight variance, and on the target.

Good luck,

w30wcf

[Longcruise]

This thread has some of the best ideas I've seen in a long time as far as improving bullet pour goes.

Enlarging the ladle hole and or the sprue hole never even crossed my mind!  Duh!

[HotGuns]

In the mean time, just preheat your mold so that the sprue takes a few seconds to harden. Your mold will be hot enough that it wont be a problem with the small sprue hole. Set your mold on the top of the pot for awhile.

I do this for my 850 grain .50 BMG  mold and have no problems.

[3584ELK]

I cleaned out the pot, melted some lead, and STILL had gunk in the pour spout!  I have found that leaving the mould on the pot is fairly ineffective in warming it up.  I dunked it in the mix, and once it was up to temp, I was making nice bullets.  

I was disappointed that the sprue plate pivot bolt kept unwinding on me, then I found the set screw had backed out.  Once I got everything adjusted it was great.

The pot pours nicely now also....thanks for your advice!

[Lee S. Forsberg]

I cast big bullets hot, 800-850, and let the lead fall quite a ways before it enters the sprue plate, maybe 1"-2". Adjust the lead stream for the size of the sprue plate hole and don't let it pile up on the plate till the mold is full. I have never opened a sprue plate hole, but I have had sprue plates made with smaller holes. Also make sure the mold is vented well. If you have a sprue plate made have the maker add vents on the bottom of the plate. Keep everything warm, just under lead temp. Hope this helps.