Powder coat varieties

[Gary]

So, then you're only speaking about long range rifle cast bullets, right? The one's I shoot to 100 yrds don't seem to have the characteristics you describe, at least the one's I've reclaimed that were shot into a dirt berm. Not arguing a point, just looking for clarification. I could see they possibly wouldn't be very good for long range.

 

[Hawk]

I may not have stated this earlier, but I have Unique, Red Dot, Blue Dot. Green Dot, Universal, AA1680, Longshot, and BE-86 covering Boolits PC'ed with Smoke's Black PC.

The Unique, Red Dot, Blue Dot. Green Dot, Universal and AA1680 have been "soaking" for 6 month or longer and seem to have no interaction with the PC.

A qualifying note is required. The Dot and Unique powders were all manufactured in the early 90's. What can I say, my Dad and I shot shotguns then and stocked up. I've got 4 pound cans of all these that were under $40.00. The universal is at least 15 years old. The AA1680 is two years old.

The Longshot is six months old and it is reacting pretty aggressively. Sticking to the PC and eating the outer layer off so the shine to the powder is completely gone. Probably half to three quarters of the boolit has powder flakes stuck to it. The exposed PC is very dull.

The BE-86 was bought last Friday and is reacting more than I had imagined. The powder is caking on layer after layer. This did not happen with the Longshot.

I was trying to find a powder for high end 10MM loads with PC'ed boolits.
My concern is not only the degradation of the powder, but also the effects to the PC., (Softening?). I do know the powder will only be in contact with the base of the boolit, but I don't want to be smearing PC coating down the bore of my guns and then ironing in with subsequent shots while putting more layers down the bore. Sorta like leading squared.

This a picture of a boolit after only two days in the BE-86. As you can see, in some places, the powder is multiple layers deep. These kernels are stuck and none fell of when I picked this boolit up with needle nose pliers to take the pic.

A gas check would probably solve this, but my bullets are all plain base.

I do have a check maker for aluminum checks, plain base in .357 and suppose I could buy one for the 40 Cal bullets to keep the powder off the bases.

.

 

[fiver]

it happens to all of them.
even jacketed bullets get metal pushed to the base.
it's just pronounced in some more than others.

I don't remember what thread it was [plain base bullets sumthin here]
where we discussed Pope noting this happening and what he done about it.

the Boolits site also has a long discussion on the matter in a sticky started by Molly airc a few [7-8?] years back.
it was titled trailing edge failure.

 

[Gary]

Where does all this slumping go with a gas check installed? Would intentionally casting undersized, even after PC cause the bullet to obturate to bore size?

 

[popper]

N.G. and TGIC are both O-N products. N.G. decomposes into NO which is a very polar gas (like a magnet) and explosive energy is reduces when N.G. decomposes. Most polyesters are glycol based. Basically 3 glycol elements in contact. Maybe a paper 'dot' on the base of the boolit to separate them? Or dipped wax?

 

[Hawk]

explosive energy is reduces when N.G. decomposes.

Should I be concerned about the multiple glass jars of decomposing bullets and powders in my closet?

 

[fiver]

as a gas it's pretty harmless.
it might be useful for some Friday night fun though.
as far as in the case.
if it produces a gas the powder becomes less energetic, but then you have a volatile gas to deal with in the chamber.
it could just produce more oxygen when it burns [leaving the powder slower] or it could make the powder burn even more efficient than it was originally [even with the slower rate]

 

[Gary]

Wow; way to technical for my pay grade. I'm just going to coat em and shoot em. If you don't hear from me again I've probably had a in situ volatile explosion, and the jar blew up.

 

[fiver]

it's not really slumping that's a different issue.

what the grooves do is gives the lead that is displaced by the lands and by the compression of entering the barrel somewhere to go.

in a normal situation we have about .002 of compression and then displacement of [say] 4 lands that are about .004 wide and .004 deep.
I'm sure you have seen pictures of bullets where there are land marks in them, and at the bottom of the drive bands there is a little tail of alloy, this goes on down the line of each drive band and ends in the little area above the gas check.
the lube in the groove is impressed like this also but squirts out into any of the tiny gaps along the edges or up onto the drive band behind it as the bullet moves forward.

 

[Gary]

Gotcha; however I haven't seen this with any of the PC'd bullets I've recovered. Probably due to the fact that I don't push them all that hard. Intriguing to say the least. Thanks for the info.

 

[popper]

My post is primarily about the PC degredation, powder is going to do what it does. I don't have any of the powders with a problem, so no concern for me. N.G. is kinda funky stuff, ignited (burns) by pressure, not heat. IMHO, Unique is more nitrocellulose (gun cotton) than N.G.

 

[Ian]

Copper-jacketed rifle bullets extrude, have core materials designed to extrude, and jackets engineered to direct that extrusion in a uniform manner. They also start out considerably smaller than what will work with our cast bullets, even with the paint coating, so they have less metal to move. That means they don't have to distort/squish as much as cast bullets do when fired, so there's less chance of them getting wongo in the bore. With cast bullets, you have not only more diameter to compress into the rifling, but you have no hard jacket to direct the displaced metal to the center/point of the bullet, it can go any old where it wants to, making an imbalanced bullet that doesn't fly well at high speed unless you control the metal movement at the point of displacement and give it somewhere to go (into lube grooves) rather than squeezing out both ends of the bullet like a soft-serve machine.

Ever notice how a soft-serve machine doesn't extrude the product in a nice, straight line?

Most monolithic bullets, even brass/bronze or copper alloy, have displacement grooves due to the nature of metal flow in a homogenous material. The grooves, like grease grooves on a cast bullet, provided breaker points for the metal moved during the engraving process and contain/control/limit that displacement to the center of the bullet so the ends don't lengthen or break their form. The bullet stays straighter and more true to the bore this way, without a bent nose or lump on one side of the base due to uneven metal movement.

 

[Hawk]

These are two boolits that have been soaking in BE-86 for two weeks. This powder was bought two weeks ago and has a code that may seem to indicate it was made in 2016.

Both boolits were pick out of the powder with needle nose pliers and the pliers were tapped on the edge of the glass jar to knock of any loose powder.

The black boolit is Smokes black from the CB forum. As you can tell, the powder has stuck on multiple layers in some places. This is a MiHec, 9MM, 125 gr hollow point that was powder coated probably a year ago.

The red boolit is HF Red. As you can see, the HF powder does not seem to react as much as Smokes, but does have a few stuck to it. This boolit is a LBT, .38 wadcutter, 140 Gr. boolit that may have been coated two years ago. You can see some places where the powder tried to stick and was probably knocked off when I tapped the pliers.

This powder seems to be more aggressive in its reaction than Longshot.

 

[fiver]

I'm still confused by this.
I just terminated my test with BE-86 because I got nuthin.
the 86 I have is not similar at all in coloring to Hawk's batch though, mine is a grey/silver color.
there has to be something in his powder causing the issue, or on mine stopping it from happening.

 

[Ian]

HF red is epoxy. I'm pretty sure Smokes is the same Polyester base with the TGIC cross-linker that I use. Times they are a'changin' with our favorite canister powders, too, can't trust nuthin'.

 

[JWFilips]

TGIC is bad juju, but safe if handled properly and NEVER inhaled or ingested. Just because the SDS for the United States doesn't yet recognize it as a high-level carcinogen/mutagen, doesn't mean it isn't bad. In Europe the stuff is already being outlawed, but the corporate pull-peddlers and law jockeys here are keeping it quiet because the substance makes a superior coating. Do some research or just use extreme caution when handling TGIC-crosslinked powder.

Ian,
Does the danger come from the dry powder or is it from the fumes when it bakes?

 

[fiver]

both..
but in different way's.

 

[JWFilips]

Great!

 

[M3845708Bama]

Ian,
Does the danger come from the dry powder or is it from the fumes when it bakes?

What about after. It is cured?

 

[fiver]

I'd say it's pretty inert at that point but I wouldn't want to huff the smoke when reclaiming the material from the berm.
look everything around us is bad for us, sand is super dangerous if you breath the dust, so is steel.
the most miserable way to go is probably steel poisoning.
a small amount of protection really goes a long way.