Oven treating powder coated bullets

[odfairfaxsub]

I'm trying something I can't find written about. I'm using my solid tray not my wire basket one for this.

heat treating already powder coated bullets.

230 gr .309 bullets left on sides made from 95 percent clip on ww
160 gr .309 bullets stood up made from 95 percent clip on ww
124 gr tl 9mm bullets 50/50 pure and clip mix stood up

im going to find out if these will harden, if laying on side affects the coated finish, and seeing how practical this might be

oven is used 400 degrees and the powder coat is hf red.

1 hour and then dropped into a sink of cold water

[odfairfaxsub]

Well at 400 degree it made no real difference in hardness. Deff not even close to water drop from the mold. They were just as soft as if I didn't do it comp to like powder coat bullets that were just from the cure process. The oven was verified by another thermometer. The laying on their side did not alter their finish from what I could tell.

[jaysouth]

Just a quick question, if the bullets are adequately coated and cured, why would you want to heat treat them again? I know someone on this board who is powdercoating WW alloy bullets and shooting them at 2,400-2,500 fps with good effect in 7mm Rem Mag.

I understand heat treating lead alloy bullets to make them harder, but doesn't powder coating make this un-necessary?

[tazman]

I have been wondering about that but had no way to measure hardness myself. If there is something different that works perhaps some one will post it.

[odfairfaxsub]

I was thinking about hardening for the sake of functioning the bullets through a semi auto. The noses I was guessing could experience deformation from cycling esp some of my pointier ones from noe 198 gr mold but I never tested it to see if there was any. Just chasing a rabbit but my intention was to do this so the bullet could sustain being functioned w little to no deformation

[cstrickland]

I was thinking about hardening for the sake of functioning the bullets through a semi auto. The noses I was guessing could experience deformation from cycling esp some of my pointier ones from noe 198 gr mold but I never tested it to see if there was any. Just chasing a rabbit but my intention was to do this so the bullet could sustain being functioned w little to no deformation

on the test bullets did you water drop when you made them ? The method I have seen mentioned on here is to water drop to achieve desired hardness, and then powder coat at say 375° F for 10-15 minutes, that way the bullet should not anneal back to normal as your heat range is not high enough. I have also seen people mention water dropping again after powder coating. I water drop jus to cool it down enough to touch as I size mine right after I powder coat. I am still working on my 300 blk loading so I do not have results I feel are definitive yet , but have seen no leading o deformation of the bullet in my AR. I am using the lee 311-155 2r so its point is a little blunt to begin with .

[sdcitizen]

My experience is that even at 375 F they do soften somewhat even in 20 minutes, the pencil test says they do, and boolits dug out of the berm agree with this. I would have thought an hour of soak time at 400 would have hardened them up again though. As to the deformation issue, I have successfully cycled the lee 309-230 through a belt fed 1919 and they don't deform any in that process, I have heard that cast in one of those is about impossible due to nose bending or breakage from the rough action.

[Ronnie Dale]

In my experience all hardness gained from water dropping from the mold is annealed out during the powder coat baking process back to whatever your alloy mix is.

Air or water dropped from the oven it matters not.

[bangerjim]

Some shooters quench-harden for obturation control in the barrel and boolit expansion properties in the target. PC acts as sort of a jacket for barrel protection, but does not give the shooter's desired effect when entering the intended target like some want with harder alloys.

You can dig into the metallurgy and science of heat treating Sb/lead alloys or just test the hardness. I too have found baking PC at 400F pretty much rids your boolits of any gained Sb water dropping hardness. 400F is just not hot enough to get the increase you do right out of the mold. That extra couple hundred degrees makes a noticeable difference, at least from all my tests.

That is why I now mix all my alloys for REAL hardness, not a "phantom hardness" created by quenching Sb alloys. That way I know my sub-sonics are all 10-12 and sonics/rifles are ~14......then PC them all.

Works for my intents and purposes. :drinks:

bangerjim

[el34]

That is why I now mix all my alloys for REAL hardness, not a "phantom hardness" created by quenching Sb alloys. That way I know my sub-sonics are all 10-12 and sonics/rifles are ~14......then PC them all.

Works for my intents and purposes. :drinks:

bangerjim
Same here. The last part of smelting is using a calculator to end up with casting ingots that are 12.5BHN hardness and 2% tin. Nothing will make that go softer.

[odfairfaxsub]

Well if they fed w out deformation in a 1919 then I'm prob trying to fix a non prob

[Yodogsandman]

I HT by heating my boolits at 450F for an hour, PC them, then return to the toaster oven and reset the temperature to 400F. After curing, I immediately drop the whole bunch, tray and all into a 5 gallon bucket of ice water (with ice).

Ice water quenched boolits should double in BHN within the first day and add a few more BHN over the next 5 days. I size them as soon as possible after quenching. I broke my table once when I waited 4 days to size them. (I used a pipe on the handle for leverage, the boolit was stuck)

As you decrease the oven heat treating temperature and increase the temperature of the water for quenching, the length of time for the boolits to harden to equal levels as above will take longer. Maximum BHN takes longer.

[el34]

Yodog, do you have a target hardness or just 'hard as possible'? Is your alloy pretty consistent in antimony content?

[Yodogsandman]

Max hardness for max cast velocity. I normally use 9 1/2 lb COWW + 1/2 LB of 50/50 bar solder. Oven HT'd this way should yield approximately 30 BHN after 5 days.

Until I started heat treating, I couldn't get good accuracy at velocities above about 1900 ft/sec. I PC in the quest for max HV and max accuracy. It hasn't happened, yet. I think I'm done PC'ing until the weather warms up next spring, now.

[el34]

Max hardness for max cast velocity.

A man with a plan and that knows what he's doing.

[Yodogsandman]

Yeah, too many plans...

[Thompsoncustom]

I heat treated a couple 308 bullets for an hour at 465 after PCing them and ice water dropped.

Haven't tested them to see if it made any difference tho.

[Yodogsandman]

I'd be interested to find out if the PC degrades or breaks down at 465F in such a short duration.

Will you be testing the PC integrity after HT'ing with a smash test?

[Thompsoncustom]

I could do a smash test and report back. I'll give it another week for they fully hardened up and smash one for testing.

I will say I shot a couple a few days after HTing them around 1700fps and there was no leading and accuracy was good.

[Yodogsandman]

It'd be nice to know if you can effectively HT after PC'ing without ruining the quality of the coating.

[popper]

Shooting HF red PC from AR10. NOTE: I do put a tad of Cu in my alloy. Can't get to 2400 with accuracy AC, works fine WD 400F/1hr, into big pail of tap water. Usually wait a week before shooting. You may need to adjust the As in your alloy. I have HT after coating (same process) and found no difference.

[Thompsoncustom]

Well have some interesting info for you,

Did the smash test and the bullet failed coating was flaking off but really nice and hard.

Funny thing is I've shot probably 30 of these from 1400fps to 1800fps with no leading(None).

Also I was shooting at 25yrd but it looked like the 30gr of imr 3031 with this bullet would be 1-2 MOA. With some fine tuning vertical stringing a tad +/- .1 grain powder and unweighted bullets.



I know when I had flaking with my Hi tek bullet they would lead like a sewer pipe pretty quick.


Added: Another thing I just thought of is this isn't the first group on PC bullets I've HT'ed I did a 100+ 9mm 124/130gr as I was pushing them to 1700fps out of my 9mm hi point carbine. A thing to note about this rifle is I can't run Hi tek in it because the bore is to rough but PC does fine. Now when shooting these hardened bullets I do remember having black specs on my right arm and thinking the coating must be flaking off but never found much lead in the barrel just a few specs on the first patch so kind of figured I must be wrong.

Now looking back the coating must be coming off at some point but for some reason it doesn't seem to cause any leading issues. I can't speak to accuracy on the hi point because the rail the holds the scope was lose from the beating of the super fast rounds and I haven't tested the HT'ed bullets since.

[pls1911]

Just joining this thread and looking for the anwer to the underlying question regarding HT efforts and PC:
Standard PC powders are designed to cure at 375-400 degrees.
At what temperatures and duration does "standard" PC material degrade?

Ideally we would like to find a PC product which would CURE at 450 degrees tolerate that temp for an hour, allowing us to icewater quench (HT harden) directly from the PC cure oven.

Has anyone tried this with a common lead bullet batch, PC'd and non PC'd for control reference, and measured BHN before and after? Test toughness and adherance?
Do I need to make the effort? I'd use .30 cal bullets of three designs all cast from a single pot of alloy.
It will be a couple of months before I can get to it.

[bangerjim]

Water dropping PC'd boolits is something I have never seen any need for. The PC hardness ranges from 24-42 (depending on who you ask) and gives both boolit and barrel protection. Uber hard boolits are no longer needed for normal shooting like B4. What are you wanting the boolit to do on the receiving end???????

I have not encountered a powder anywhere that cures at 450. All seem to list 10 min @ 400F. You could over cook them at 450, especially for an hour (!!). But try it and let us know. You may want to contact some of the MANY powder mongers on the net to ask if they have hi temp cure formulas avaialble for you.

I use 9-12 Bhn for all my PC's boolits for subsonic. ~14 for sonic. All alloys are MIXED for hardness needed via air cooling. I do not rely on any pseudo-hardness derived from water dropping as in the old days. Personally do not see any need for it in what I do.

Let us know about the hi-temp powder search!

banger

[tazman]

I had some Lyman 358212 146 grain round nose boolits I powder coated and then cured at 400 degrees for 15 minutes(Smoke's powders, wonderful stuff). When I loaded then into the cases the boolit squished a little bit. Enough so that the nose profile changed noticeably and some of them refused to go into battery without some persuasion. Oddly enough they all shot accurately.
I have since water dropped some of the same boolits right out of the oven and did not have this problem. Perhaps this was a one off occurrence. I hope so because the powder coating is starting to show some promise for me, at least in some of my weapons.

[pls1911]

In my experience high speed (2100 fps) lead bullets in Microgroove barrels require oversize (.310 -.312), gas checks, and substantial hardness to maintain accuracy.
Notwithstanding the hardness of the PC skin a number of performance factors need to be answered before I'd consider shooting "unlubed" bullets through some collectable barrels of pre 1900 guns as well as post '55 items.
At this point of my limited reading, I'd have to admit PC processes look very promising.
I'm new to PC, but experience and research should provide answers.

[popper]

Going to try something posted, 3x PC on plain base. DTPC this morning, second coat, 30F outside, ~40F in the garage, low R.H. second coat took about 10 sec. to get good coat, cooked for 10 min @ 410F, AC. Will apply 3rd. in the morning, cook, size, then HT some, AC some & compare. 145 gr PB for 300 BO. Claimed accuracy with the Lee BO boolit is supposed to be great this way. We'll see. If it works I'll try for the MG 30/30 next.

[Whizzer]

I am also very interested in this approach. I tried to cook a batch of Smoke's Signal Blue @375 degrees for 15 minutes (BB Dry Tumbled) on previously water dropped, 357 Magnum Clip On Wheel Weights, thinking I was preserving some of the Hardness. I have a Cabine Tree Hardness Tester, but haven't tested them yet. (Too busy at work)

It seems like Heat Treating for an hour @450 and then an ice bucket quench might be a better solution. And, I wonder about the sub freezing temps that salt water might provide also. More of a "tempering shock" maybe? Just thinking....

I am no metallurgical whizbang. That's for sure!

I'm a little short of time just now, but the weekend will be here soon enough. I might do some Hardness Testing under the PC after filing some flat spots.

[popper]

Actually finished the BO & started the 30/30 last nite. HT final cook was 410 for 1 hr, dropped in water left outside ~26F, from a wire basket I use for HiTek cooking. No messed up surface finish.
I've been pushing these >1800 fps, I'll see if the extra coating help.
edit:I did notice that the 2,3 coats went on really easy. Think this is due to my uncoated being damp, stored in a plastic jug after casting. Cooking drove off the moisture and coated doesn't hold any moisture at all. Weather report show RH @ 42%, 33F. Air is really dry though.
edit: HT for 30/30 didn't do so well. 420F, jumbled in tray, ~50 had very small bits of PC missing after dumping in water & sorting. Either stuck to mesh tray or scraped off when dumped into the water. Just redo, got ~100 good ones.

[Thompsoncustom]

Looking forward to your results.

[bangerjim]

Actually finished the BO & started the 30/30 last nite. HT final cook was 410 for 1 hr, dropped in water left outside ~26F, from a wire basket I use for HiTek cooking. No messed up surface finish.
I've been pushing these >1800 fps, I'll see if the extra coating help.
edit:I did notice that the 2,3 coats went on really easy. Think this is due to my uncoated being damp, stored in a plastic jug after casting. Cooking drove off the moisture and coated doesn't hold any moisture at all. Weather report show RH @ 42%, 33F. Air is really dry though.
edit: HT for 30/30 didn't do so well. 420F, jumbled in tray, ~50 had very small bits of PC missing after dumping in water & sorting. Either stuck to mesh tray or scraped off when dumped into the water. Just redo, got ~100 good ones.

If you must WQ your PC'd hot boolits, you might want to consifer a water tray you can dunk the whole rack in rather than 'scraping" them off into a bucket That PC is very liquid at 400F and will damage pretty easily. Leaving them on the rack and dunking the whole thing in will minimize any damage from banging around.

Give it a try!

banger

[RP]

I second dunking the entire tray or rack to protect the PC for reason stated. Concerns would be if it effects how well the PC bonds after the fast cooling may want to check that as well. My thinking leans towards air forming between the lead and the coating making a bubble that then may burst and the PC may lay back down without being bonded. :popcorn:

[popper]

Normally cook & WD @ 400, trying higher temp, HT after sizing. The BO @ 410F didn't have the problem, just the 30/30 @ 420F. Pretty sure it's just making the HF red PC sticky & jumbled stick together a tad. These are 10-30 thous." dia pits, a few lines. I normally cook base down & tip the plate to dump in H2O but the glue holding the plate together finally failed after a year. Still using the same sheet of NS foil but it's going to tear when I fix the plate.

[gpidaho]

I'm in agreement with Banger J on this. Although I use the cold water quench to harden boolits when using lubes, with the PC boolits I just use an alloy that is hard enough without the water drop. Like other variables, I have found some of my rifles to prefer lube over PC and in some the fit is just better one way or the other. When my goal is no nose deformation in the autoloaders my alloy is pretty hard,3ww 2lino +2% tin in most revolver loads ww+2% tin works great for me. 95% of my handgun loads and about 50% of my rifle loads are PC'd and I'm sold on the process. GP

[edctexas]

A newbie take. You can not measure boolit hardness through the PC coating. Some of the guys like Banger and Popper know this already. Getting the PC off to test hardness is a pita. I am learning so please keep posting. I read it all!

Ed C

[bangerjim]

A newbie take. You can not measure boolit hardness through the PC coating. Some of the guys like Banger and Popper know this already. Getting the PC off to test hardness is a pita. I am learning so please keep posting. I read it all!

Ed C

Very easy! Just grab a file and make nice smooth shiny lead area on your boolit and test away.
You have to do that anyway with that Lee thing.
banger

[Whizzer]

I file a faux "meplat" for testing on my Cabine Tree also. I flatten and/or smooth both ends, so the boolit won't slide around when making the indention. But I HAVE NOT filed through the powdercoating yet to do this test--only plain or lubed, mostly 45-45-10.

Maybe I'm in for a bit of a surprise, but I don't think so...

[popper]

Seated a PCd, sized, HT boolit for the BO today, about a week old. Measured 310 before & after seating. M expander is 306. Pulled a already loaded 300 boolit, PCd, HT, sized 310, came out 307. Guess I found my answer & new process.

[Yodogsandman]

Very easy! Just grab a file and make nice smooth shiny lead area on your boolit and test away.
You have to do that anyway with that Lee thing.
banger

Couldn't you file a flat on a non-PC'd boolit and HT that at the same time with your batch for the test? Filing a flat on it after PC would cause work softening of the surface.

[bangerjim]

Couldn't you file a flat on a non-PC'd boolit and HT that at the same time with your batch for the test? Filing a flat on it after PC would cause work softening of the surface.

This is not an NIST testing lab!!!!!!!!!!! OMG. [smilie=p:

Gently filing off a bit of the PC to make a small flat spot is not going to alter the molecular structure or the hardness of the lead enough to be even read by the VERY crude tools we all use.

BHN within 2 units is good for most of us.

And we are testing much deeper than just the surface.

Just do it.

bangerjim

[Yodogsandman]

A better method of testing would help to improve accurate readings. If the method is flawed, the test results will also be flawed. The method I've suggested is better and takes no more effort than yours, so... why not just do it?

I promise you don't have to wear a lab coat.

[popper]

Just put some tape on the surface you want to test, then PC. Or use acetone to remove PC. I think you 'clean' the surface for the tester to get below surface imperfections so you can measure dia. accurately.
My previous comment about temp related to the thermoplastic HF red. It appears to be ok @ 410, but gets sticky@ 420 - PID controlled oven. If going above that I recommend setting them on the base to cook, not jumbled in a tray.

[Whizzer]

I didn't think tape would survive 400 degrees.

Have you tried it, Popper?

[gpidaho]

Whizzer: Eastwood sells heat resistant tape for masking items to be oven cured. Also handy reusable caps and plugs. GP

[Whizzer]

Ahhhh. Good to know, gpidaho.

And now that you mention it, I probably already have some tape that will work. We print coffee mugs at our Screenprinting and Embroidery shop with the dye sublimation process. We use hi-temp tapes in that process to locate the printed paper before clamping with the mug presses. ~400 degrees for 12 minutes. Perfect.

I wasn't thinking....

But I can't play now. I'm buried in work this week.