Does annealing bullets shrink them a tad?

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Swampman said:
John,
Did you change your powder coat process or powder type since you got an increase in diameter with your earlier powder coating attempt?

I've always gotten an increase of .0015 to .002 when I do "shake-n-bake" powder coating with Harbor Freight red. I've always thought the increase was a given, like death and taxes.

I can't explain or even understand exactly what's going on here, but the good news is that your bullets are shooting very accurately.

Is your mold brand new or did you get it used? I ask because perfectly round bullets with that kind of size variation aren't typical of Lyman. If it's used, a previous owner may have honed it out.
Click to expand...
Molds are new. Powder coat is Eastwood Ford blue. They were the talk of the range last Saturday, such a pretty blue. LOL.
 
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forrest r said:
My cast bullets are 2/1000th's"+ larger in diameter are they have been pc'd.

You're using a 12bhn alloy, there is no way that that 44cal bullet is going to shrink that much due to heating them in an oven after water dropping them. A .452" bullet using 90/5/5 will only shrink .0015" if you anneal it back to dead soft.

You're only using 95/2.5/2.5 and you are not annealing the bullet back to dead soft.
You have too much tin in your alloy to affectively heat treat your bullets. This also affects how much hardening you get from water dropping them.
If you go over to the castboolits website and do a search you will see that the question "Will water dropped bullets be larger in diameter than air cooled bullets?". Multiple posts with alloys & measurements have shown a 44cal bullet will grow .0004" max when water dropped. You can get that much variance in bullet diameter from the high/low mold temps during a casting session.

With you having +/- 2/1000th's" difference in your bullet as cast you will never get any meaningful results with measuring random bullets. What you need to do is measure 10/20 bullets and size them & measure them. Out of round bullets do nothing for you. Then pc them and measure those bullets again. You'll see a huge difference in your results along with finding out how much pc (1/1000th", 2/1000th", etc) you're actually putting on.

Alloy .308 .357 .452
Linotype .002 .0025 .003
Lyman # 2 .0025 .0025 .0035
Soft Lead .0035 .004 .005
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I wasn’t sizing the bullets because my bullet sizer is .430 and my barrel is .431. I was powder coating in the hopes that would add diameter. Back when I shot some bullets sized at .429, about 20% keyholed at fifty yards and also leaded the barrel. Kind of done with that nonsense. Haha.

Ordered some more bars from Rotometals and have decided to stick with Lyman No. 2 alloy. The greater amount of antimony drops slightly bigger bullets which works better for all my molds. I plan to air cool from here on out. But I bent a bunch of 30 caliber noses last Sunday air cooling, so need to get some more cotton towels and be a little more patient. I also frosted a few, so need some refinement in my technique.

Hope to load a few tomorrow night so I can test shoot this weekend.
Got out the second 30 caliber mold last weekend, so the 30 caliber bullets gonna have a shootout contest this weekend. Last time I did that the bore riding design shot the most accurate but the Ballard design shot faster before going all shotgun pattern.
 
sizing the bullet round will tell you if your bullets are truly shrinking. You don't need to pc them simply take some culls and size them and toss them in with the pc'd bullets. Measurements before vs after will tell you what's going on.

Don't know why your not getting 2/100th's"+ with your pc coating. Perhaps you might consider a 2nd coat if you can't get enough pc on in 1 coat.
hi-tech ='s thin coat
pc ='s thick coat
.
If you need a .431" bullet you should be looking for another mold. I use nothing more then range scrap for +/- 99% of my 44cal cast bullet needs that is 8/9bhn. Out of the 10 44cal molds I have left (thinning the herd) 2 of them cast a .430" bullet with the range scrap. The rest range from .431" to .433" with that same range scrap alloy.

You might consider selling that 4-cavity mold and ordering a new mold from NEO or Arsenal.
https://noebulletmolds.com/site/
http://arsenalmolds.com/index.php?route=common/home

Both of those companies make excellent molds & if you tell them the alloy your using and what bullet diameter you're targeting they will cut your mold for those specs. More often then not an off the shelf/standard mold will work.
 
forrest r said:
sizing the bullet round will tell you if your bullets are truly shrinking. You don't need to pc them simply take some culls and size them and toss them in with the pc'd bullets. Measurements before vs after will tell you what's going on.

Don't know why your not getting 2/100th's"+ with your pc coating. Perhaps you might consider a 2nd coat if you can't get enough pc on in 1 coat.
hi-tech ='s thin coat
pc ='s thick coat
.
If you need a .431" bullet you should be looking for another mold. I use nothing more then range scrap for +/- 99% of my 44cal cast bullet needs that is 8/9bhn. Out of the 10 44cal molds I have left (thinning the herd) 2 of them cast a .430" bullet with the range scrap. The rest range from .431" to .433" with that same range scrap alloy.

You might consider selling that 4-cavity mold and ordering a new mold from NEO or Arsenal.
https://noebulletmolds.com/site/
http://arsenalmolds.com/index.php?route=common/home

Both of those companies make excellent molds & if you tell them the alloy your using and what bullet diameter you're targeting they will cut your mold for those specs. More often then not an off the shelf/standard mold will work.
Click to expand...
I am getting .431 -.433 from the mold, so it’s good. Prolly get more diameter with the Lyman #2 alloy to be delivered any day now.
 
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