Hardness on Powder Coating

[sixshot]

I still get a fair amount of PM's asking me about the hardness of different alloys after powder coating & how to check it. Some guys are using straight WW alloy to cast with, some are using my favored 70% WW, 30% pure lead alloy, some add tin, some are going 50/50, etc. & then painting & baking for 10 minutes. The questions I'm getting are, what is the best way to test the hardness after baking & how do you get a clean base to check the hardness.
In the past I've tried applying a GC, then popping it off, I've used fine sand paper & gently sanded it off. The old Lyman GC's didn't crimp so they were easy to get off but still it could give you varying results. Most times the hardness was running from 8-10 but then the light finally came on!! Why not just cast them & then bake them in the toaster oven for 10 minutes like I normally do without ANY paint & check for hardness!!! That was it, perfect results, you are getting true results because both ends are "clean" & they've had the 10 minute heat treat in the toaster oven. You'll find there is very little difference in hardness, regardless of what alloy you mix after the 10 minute heat treat at 400 degrees & then perhaps a 48 hour age.
The biggest thing a different alloy gives you is a different weight, not much of a different hardness after the heat treat. Good luck!

Dick

[COR]

It's funny how you can get too close to a problem...This is interesting to me as I had suspected it wasn't much "softer" from my non scientific results involving a hammer...I originally thought it could affect it but after seeing what the bullets looked like following shooting at steel they looked like the traditionally lubed ones.

Great info Dick.. thanks!

[Shakey]

Atta-boy Dick!

Thanks for the tests and report. I believe the results are what should be expected with bullets that were originally air-cooled. After all, you are not changing the alloy and the cool down is simply a repeat of the original cool down after casting.

However, I would expect bullets that were originally water-cooled to lose the 'extra' hardness that the quench created. Reheating and air cooling them is basically an annealing process.

This is not really important to me because I have no need for the harder bullets but, it may matter to some of those who do feel the need for them.

Did any of your tests involve water cooled bullets?

[sixshot]

Shakey, I haven't water quenched in a long time, really not much need in most revolvers except maybe the 357 Maximum or for those who need max velocity for dangerous game like Texas jackrabbits, javelina, armadillos & 11 foot rattlesnakes (think 2 Dogs) As velocity goes up hardness has to go with it so water quenching has it's place, I seldom need it here in Idaho for deer, lion, antelope, bears, elk & moose, all of which fell to air cooled, 3/4 throttle loads. Getting serious now, I think the last time I quenched was when I was testing powder coated bullets. I was taking them right from the toaster oven & quenching, there was a small increase in hardness, that's because you are only running 400 degree's for 10 minutes so the BHN makes very little change from air cooled.

Dick

[2 Dogs]

I'm pretty sure my good friend, mentor and "tormenter" is making the above comment about hardness has to go up when velocity goes up about PLAIN base bullets.

I have shot very few powder coated bullets. Mostly because I'll probably be older than Dick's crocs by the time I run out of bullet lube and gas checks. However, I have tested cast bullets as soft as 8-10 BHN WITH a gas check at up to 1800 fps with no leading and explosive expansion.

[bradshaw]

I have shot very few powder coated bullets. Mostly because I'll probably be older than Dick's crocs by the time I run out of bullet lube and gas checks. However, I have tested cast bullets as soft as 8-10 BHN WITH a gas check at up to 1800 fps with no leading and explosive expansion.

[/quote]
***
Fermin.... perhaps one of the dinosaurs will come on board to describe the lead used in early factory .44 Mag----240 grain SWC swaged to a copper base. These slugs land in meat like thunder. Somewhere between hard and soft. Loaded full house. Rivets the nose, a flare not a mushroom. Your soft cast gas check----driven hard without leading----sounds like a great tool.
David Bradshaw

[sixshot]

Yup & Yup! Another thing about gas checks is, and I hate to admit it but it's true, many times a gas checked bullet will out shoot a plain base bullet, simple truth. A powder coat bullet recovers some of the difference.

Dick

[paul105]

Dick,

Thought I read somewhere on the forum that Tank was using 20 min at 400 deg -- of course I could have misread/misremembered. Anyway, how much difference, if any does this make.

Thanks,

Paul

[BigBore44]

Nov 5, 2016 9:08:45 GMT -5 paul105 said:

Dick,

Thought I read somewhere on the forum that Tank was using 20 min at 400 deg -- of course I could have misread/misremembered. Anyway, how much difference, if any does this make.

Thanks,

Paul

That's what I do, 20 mins @ 400*
I don't know if right or wrong but that's how I usually do it...??

BigBore44

[gman50]

Several months ago this conversation took place on another forum when it was asked how the baking would affect the known bhn. I took a handful of bullets with a known bhn of 19 and placed them in an oven that was up to temperature @400 degrees. After placing them in the oven and the temperature gets back to 400 degrees I timed for 10 minutes as this is the baking directions for my pc'ing process. Bullets tested went from 19 bhn to 10 bhn. Tested after 10 days they tested 11 to 12. My bullets tend to air cool at 13 bhn and always settle to 10 after pc'ing. I quenched some right after coating that we're back to 13 bhn and after 10 days tested 17 to 18 bhn. Just thought I would pass on what I found.

[boolitdesigner]

A long time ago now (about 36 years or so) I wanted to know exactly what I got from water dropping several antimony, tin, arsenic and lead alloys. Actual numbers rather than the notional hammer on the bullet test. I borrowed some testers off of friends in the industry before I got my own. I tried this with several alloys and lots of bullets over a year and a half elapsed time from heat treatment (water dropped and oven heat treatment). I found that antimonial/tin/arsenic alloys do not instantly jump up to their maximum hardness. Water dropped or oven heat treated will gain moderately fast in hardness till you hit two weeks to a month till they settled down somewhat in hardness growth, then raised in hardness slowly until I quite testing.... it depends on how much of each of those three items are in the alloy, the quench temperature, how long you kept them there and how close to the slump temperature you where. Until you get over about thirty minutes of soak time with oven heat treating, it will take several weeks to tell a large difference in what the hardness is. Try the hardness later and see what you get.

[ebg3]

I shot some yesterday and a bit today. I used isotope lead, I think it's similar to WW, and cast 44 Keith bullets. I air cooled and then powder coated with HF red paint and baked for 12-15 minutes at 400. I don't size after coating. Loaded over 21 gr 2400, they shoot very well in my 6" Dan Wesson, 8 3/8" 629 C, and in my buddy's 6" 629. After shooting all 3 guns today, a couple hundred rds total, there is zero leading in any of the guns. Accuracy is good in all guns with this load; the Dan Wesson out shoots both Smiths. I find the 255gr GC Keith-style bullet to be a little more accurate in my 44's, over the plain base or PC bullet. I don't powder coat the gas checked bullets.

[2 Dogs]

Nov 20, 2016 18:34:40 GMT -5 ebg3 said:

I shot some yesterday and a bit today. I used isotope lead, I think it's similar to WW, and cast 44 Keith bullets. I air cooled and then powder coated with HF red paint and baked for 12-15 minutes at 400. I don't size after coating. Loaded over 21 gr 2400, they shoot very well in my 6" Dan Wesson, 8 3/8" 629 C, and in my buddy's 6" 629. After shooting all 3 guns today, a couple hundred rds total, there is zero leading in any of the guns. Accuracy is good in all guns with this load; the Dan Wesson out shoots both Smiths. I find the 255gr GC Keith-style bullet to be a little more accurate in my 44's, over the plain base or PC bullet. I don't powder coat the gas checked bullets.

I have a quantity of isotope lead. My lot is a bit harder than pure lead but quite a bit softer than WW. Sounds like you got yourself a nice recipe!

[sixshot]

ebg3, your 21 grs. of 2400 in the 44 magnums has been my favorite for almost 50 years & I agree that many times a GC 44 bullet will have a slight accuracy edge over the plain base but in all my years of using PB bullets I've never seen enough difference at game shooting distance to win me over. Powder coating usually shoots as good if not better than conventional lubed bullets, at least that's what I"ve found after several thousand in several guns over the last 3 years. The guns are always cleaner by a huge margin.

Dick

[ebg3]

I've been really happy with the isotope lead. With homemade 50/50 lube it has done well in the 44 mag and 40 S&W. Powder coating has worked very well for my 44's. The PC bullets do seem to have an accuracy edge over the plain base bullets and with little smoke. I'm sold on powder coating, it's great.