My powder coating method

shuz

Active Member
Do any of you folks heat your coated bullets to about 525 deg F. and then dump them into cold water?
 

fiver

Well-Known Member
i would too.
I pull mine from the oven and dump them in cold water.
but they are at 400-F
the melt point of tin is abut 450-F and it will start to melt and sweat out of the alloy which is what causes the slumping.
 

shuz

Active Member
The boolits I've done this method with are RCBS 25-100 & a clone of Lyman's 311041 and have seen no signs of slumping. However the resulting bullets are "harder than the hubs of hell". The alloy used is tested Saeco 5 before powder coating and heat treating and ended up as Saeco 11!
My concern is that with the 25-100's, when I went to size them from .262 to .258, some of the coating was rubbed off, exposing a lead streak lengthwise along 2 sides of the bullet. The lead streaks were on both sides of the bullet and apparently 180 degrees from each other. Is this an indication that the Lyman H die is out of round?
I have not played with the 041 clone yet.
If I size the 25-100 to .258 first, apply a gas check, and then powder coat, the end result is a bullet that mikes .258. I only wish I hadn't powder coated so many before sizing them!
 

Ian

Notorious member
Shoot them fully annealed after coating or at most 425⁰ for 45 minutes befire quenching. I didn't find my powder-coated/gas checked .22s needed to be any tougher than air cooled wheelweight alloy plus 1% tin up to 2800 fps and only a small accuracy benefit from bumping to 19 bhn via mild heat treat to over 2900.
 

Hawk

North Central Texas
I size mine before coating and again after coating.
I just send them all back thru the Lee push thru sizer.
 

popper

Well-Known Member
Closer you can get to slump temp before freezing them harder they get. Try some BLL or other 'lube' on them before sizing, just a VERY light coating (over PC) helps not scrape PC off or distort the bullet. I use ~ 4 drops/100 rifle bullets tumbles for a few seconds. Also keeps the bore shiny! I apply GC with oversize sizer, tumble coat and cook, BLL & size to desired. Presizing works but some alloys will lead up the Lee.
 
Last edited:

JWFilips

Well-Known Member
I size mine before coating and again after coating.
I just send them all back thru the Lee push thru sizer.

Same here!
The only one I don't size at all before or after coating is My .25 auto pistols bullets....the are a tad skinny on casting and then the are a tad fat on coating! but The Spanish auto likes them that way!
 
Last edited:

shuz

Active Member
Yes the bullets were .261-.262 before sizing. Well, some of them were. But in the past I've been able to correct slight oor conditions by sizing.
With this Lyman die, I've had .259 bullets come out of the sizer .257-.258. IE if I measure, and then rotate the bullet slightly, one reading is .257 and the next is .258. The way I see it, no die marked 258 should give a bullet a 257 reading. Am I off base here?
 

fiver

Well-Known Member
well believe it or not some sizers give you the size they say, they ain't that size.

how it works is the sizers are cut to certain alloys, and there is a slight amount of spring back associated with each alloy.
some manufacturers follow that rule and others make the hole the size you ask for.

luckily we can fix many of the issues ourselves by gently lapping the die [with high number wet-dry sand paper, a dowel, and a little oil]
or by running lapping compound laden bullets through the die over and over.
 

shuz

Active Member
As I see it, by lapping a die that gives a .257 diameter on one side of a bullet, the result will be a die that gives a .257 diameter all the way around the bullet!
I'm looking for a die that gives .258 bullets. If I need compensate for springback in order to get. 258, I'll use my .257 die.
 

fiver

Well-Known Member
mmmhmm you'll open it and round it, because the lap will work on the 'high' spots much more.
 

shuz

Active Member
You're right! I wasn't thinking clearly about this! How would you suggest to open the die up to .258 all the way around?
I don't have a lathe or other machining tools. Can this be done with a drill or Dremel tool?
I have heard that these dies are hardened.
 

fiver

Well-Known Member
wood dowell.
strip of paper.
hack saw a slit.
wrap the paper.
run it up and down with your drill.
a quarter inch dowel should work.
probably only 10 maybe 15 seconds will be enough.
 

Brad

Benevolent Overlord and site owner
Staff member
I used 400-600 grit wet/dry sand paper. It depends on how much you are removing. Doesn’t take much to remove .0005 at all.
Go slow, clean and measure often. Damn easy to remove more, impossible to put it back!

Don't forget that final size can change based on alloy and hardness. A heat treated and hardened bullet will measure different from the same alloy air dropped and freshly cast. Harder alloys tend to spring back more. A Linotype bullet could measure .001-.0015 over what a pure lead bullet might measure, depending upon bullet diameter.
 

shuz

Active Member
The boolits I've done this method with are RCBS 25-100 & a clone of Lyman's 311041 and have seen no signs of slumping. However the resulting bullets are "harder than the hubs of hell". The alloy used is tested Saeco 5 before powder coating and heat treating and ended up as Saeco 11!
My concern is that with the 25-100's, when I went to size them from .262 to .258, some of the coating was rubbed off, exposing a lead streak lengthwise along 2 sides of the bullet. The lead streaks were on both sides of the bullet and apparently 180 degrees from each other. Is this an indication that the Lyman H die is out of round?
I have not played with the 041 clone yet.
If I size the 25-100 to .258 first, apply a gas check, and then powder coat, the end result is a bullet that mikes .258. I only wish I hadn't powder coated so many before sizing them!
I may have "mispoke" about the bullets not slumping after being heat treated to 550 deg. whilst powder coating. Yesterday I got some real nice groups around 1" for 5 shots several times with 15.5g of Reloder 7 and bullets that were either just heat treated normally with no powder coat, or heated to around 400 with powder coat. Then I shot some of the 550 deg bullets, one group was around an inch, and the next group opened up to 4 or 5 inches! Only thing different was the bullet. I guess I gotta get me a dial indicator and check for run out.