What do you Cast/size your 9mm powdercoated bullets to?

[popper]

Same size as for normal lube! Else they will tumble - but they still blew bigger holes in the 10 ring, as tested yesterday @ 7 yds. Some just tipped, some went sideways.

[prickett]

Pricket- your description of leading sounds like a soft alloy issue to me. Like you are right on the edge of the chamber peak psi in lead tensile strength. PC should solve that issue since if the chamber pressure overcomes the alloy tensile, it still cannot gas cut which causes most leading. Getting adequate hardness for 9mm can be a challenge since it's a rather high pressure cartridge. I found I was only able to meet book spec on hardness with pure WW water quenched. For context I was able to go 1/4 to 1/3 ww to scrap (pure I think) plumbing lead for .45 since it's a much lower pressure cartridge.

I was using WW and water quenching my 9mm boolits (and using traditional lube). The jury is still out on my PC boolits as I'm giving them time to age harden after the cooking removed the benefits of water quenching.

[totalloser]

Ah, not a hardness issue then. That should have easily gotten the hardness up there. I wouldn't worry much about waiting. I have been blasting merrily away using an even softer alloy than I was using for .45 shooting .40 cal PC which is pretty similar (to 9mm) in the way of chamber pressure and velocity. I'm sure I picked up some precipitation hardening, but I know *some* of the boolits I was blasting earlier today, I cast day before yesterday.

Sorry for the hi-jack.

[Maximumbob54]

I started to size most of my 9mm bullets at .357" but my Beretta 92FS still demands .358" or I get a good buckshot looking pattern on the target. I did find the coated bullets sized at .357" also work in my .38's when sized at .357" while the lubed lead that was a BAD idea in the past. So just like sort of mentioned above, I'm finding that I enjoy this for more reasons than I started with and am finding new reasons to like it still.

[mdi]

I am under the impression that powder coating negates any need for harder alloys. The coating protects the bullet from gas cutting and the coating will grip the rifling just fine...

[w0fms]

Drops at .3575, PC, resize to .357. Good for 9mm and 380...

[totalloser]

I think I might be seeing a pattern with tolerance and intolerance with sizing. Dunno if there is anything to it, but it sounds like when there is a need for .358" in a 9mm application it is in a conventional rifled barrel. I wonder if the polygon barrels are more tolerant of variations? This might be a new angle since casting for polygon barrels has been a contentious issue in the past, and with PC quickly catching on more people are going to be casting for them.

MDI: Sort of. With lubed, if the peak pressure overcomes the tensile strength of the boolit for long enough to blow out the lube, then gas cutting occurs. This is why books call for tensile significantly above max chamber pressures.

PC eliminates this issue entirely, but there is still another issue that will crop up if the chamber pressure is significantly higher than the tensile of the boolit: The chamber pressure vs friction against the rifling will deform the boolit. I suspect that the hardness can be about 70 or 80% the max chamber pressure and work fine so that is roughly what I am doing. But I have read about problems with too soft of alloy and too high of chamber pressure not working even with a good PC. The way I'm reading this is that the reason you can have softer than peak chamber pressure is that the bore friction cannot apply the full force of resistance against the chamber pressure and thus does not subject the alloy to that force. Effectively this force is a shear force, but lead is quite malleable and not prone to full shear failure.

Now before the books on thermodynamics come out there is a reason this can happen: The inertia of the boolit itself soaks up the difference in force, and the inertia will not be subjected to tensile forces. In short the inertia acts as a cushion to soften peak pressure forces against the alloy. But if I'm right (and real world testing has held this true) you can go significantly softer, but some hardness will be needed for "modern" high pressure cartridges such as 9mm.

[Maximumbob54]

IMHO....

All of the above is a definite maybe. I got very excited when I made a .357 magnum load with soft scrap lead and got some pretty decent 15 yard accuracy from it. And then that very same bullet has yet to find an accurate .38 special loading. And yet all of my lubed lead bullets made from that exact same batch of scrap lead work just fine in .38’s but are just too soft for even mild magnums. I don’t get it. Someone once said there is a certain amount of black magic in casting and I think there is as well in coatings.

[RP]

I may be off base on this but I think the first ? was more to if you would size your bullet like you would a plain lead and lube for a PC bullet or treat it more as a jacketed bullet because of the coating. I also agree with some of the other post some shoot good before coating others do not I lean towards of the slickness of the coating and maybe a better crimp or change in speed. So far I have been sizing to pre coating specs for mine but will be looking into other paths as this process continues. I am hoping for better performance out of lighter bullets in my 300 BO and using softer alloy in my heavies. Right now my problem is with soft 247grs I get bullets that deform on sizing and or seating. More shop time since hunting season has ended and my time can go for finding out what is going to work for me.

[mdi]

Jes wondering if kryogen has slugged his barrel yet...

[bangerjim]

Jes wondering if kryogen has slugged his barrel yet...

Don't even ask.............or you will pisssss him off again! HA..........ha.

banger

[Elpatoloco]

I use a Lee 6 gang tc tl mould sized after powdercoating to .356. Its the only lee mould that I own or will ever own. After about 2000 slugs, the front cavity is junk. Fought it the whole time and just wrote it off. The slugs are good and I have no tubling problems out of anything they have been shot out of. In fact, they group quite nicely.

Im thinkin of ordering a quality mould of the same design.

[poppy42]

I size all my 9mm to .356 with zero leading an excellent accuracy. I cast and shoot Lyman 356402 -120 grn, RCBS 09-115-115 grain, Lee tl-356-2r 124grn, Lee tl-356-tc 124 grn, and Lee 356-2r 126 grn. I don’t powder coat my pistol Boolets. The tumble lube Boolets get Ben’s Liquid lube, And the conventional lube bullets get Ben’s red. I would say the Boolets dropped From the R CBS mold are the most accurate followed closely by the Lyman 356402 And the Lee 356-2r. But the accuracy out of any of them is more than acceptable. I’m Talkin same hole accuracy. At least it’s a distance is my old eyes can see.
Oh and I hate autocorrect !!!!!!!

[fredj338]

quit telling me to slug my barrel... this was not my question. my barrel is 357, like almost all 9mm barrels...

Not sure where you think most modern bbls are .0357", my Glock bbls are not even 0.356.
I size all my PC after coating to 0.356", they shoot fine, no leading, very good accuracy in several 9mm, including my match bbl 1911 with conventional rifling. I used to run 0.357" but had issues in some guns with mixed brass chambering. So pretty much 0.356" for everything.