Hard carbon removal from barrel?

[SwampShooter]

Okay so I'm working on getting a G22 to swallow PC pills. There are some issues. I'm using an OEM barrel and also an Alpha Wolf barrel. I had run about 20-30 rounds of HF red and ended up with some really hard deposits in the OEM barrel. The thing is I can't swear they weren't there before but I've put many thousands of copper plated down the pipe and had not seen anything. I had wanted to try an Alpha Wolf barrel anyway, so I contacted the Barrel Fairy and sure enough a new barrel magically appeared before too long. Long story short is I ran about 30-40 rounds through the new barrel (Smokes power this time just in case it was a HF issue) and no problems. I ran brush and dry patch through the barrel after 1 round then another 2 rounds, 5, 10, and then finally 20 rounds. Barrel was clean as can be after each set. Win, yippy, whoohoo, do the snoopy dance, etc. So I loaded a few hundred rounds and proceeded make holes in paper, life is good. Well I was wrong, some of the same deposits. I have a number of theories as to why (pills too small, too hard, etc.) and I will explore them in due time. First I need to get this stuff out. So far I have try Shooters Choice with lots of scrubbing and even soaked the whole barrel for a few days. Nothing with Hoppe's #9 either. At this point I wasn't sure if it was PC or carbon so I soaked the barrel in acetone for a couple of days, same result. The stuff is coming out, I get some black on a patch (actually a noodle of paper towel) after I scrub. The thing is at this rate I'll need to intermittently scrub my barrel for a month before it's clean. I mean I have no problems with using elbow grease but... Any ideas so I don't have to reinvent the wheel blow up my arm/elbow? I'm contemplating a soaking type carburetor cleaner, it shouldn't harm the metal but I'm not so sure about the finish. I let some Kroil sit in the barrel overnight also and I have some JB paste on the way. Oh, I've used about a quarter of a copper (not plated) scrubby pad worth of strands on a bore brush in the process of this. If it helps, the fouling starts past the throat and then peters out about and inch or so down the barrel.

Thanks

Swamp

[popper]

Cook the PC properly. Use the right alloy.

[SwampShooter]

Well yes, I'm going to need to tweak things. That may turn into another post if I get stuck. I just need to get the fouling out before I can do that.

[ShooterAZ]

Some powders seem to leave more carbon than others, at least for me anyway. Titegroup comes to mind. It leaves a deposit on the cylinder of my stainless revolvers that is pretty difficult to remove. Kroil has worked well for me to remove carbon. For the bore I will wrap a patch around a bore brush, dip it in Kroil, then smear a dab of JB Bore on it. After that "elbow grease" is your friend.

[Smoke4320]

BORE TECH ELIMINATOR is the product you want for pc residue removal

[Dragonheart]

My best advice is order a Glass Taylor Oven Guide Thermometer $12 from Amazon and set it where you read it through your oven door. Cheaper than bore solvent and a whole lot less effort. I would use the HF powder on PC other things other than bullets.

[igolfat8]

Good old, inexpensive, Simple Green used full strength will remove it. Spray barrel, let soak for 5-10 minutes and all burnt powder residue will come out easily with a patch or light brushing.

[Dragonheart]

Good old, inexpensive, Simple Green used full strength will remove it. Spray barrel, let soak for 5-10 minutes and all burnt powder residue will come out easily with a patch or light brushing.

Good idea, but the problem he has is not carbon, it is cooked on polymer that came off under cured bullets. A partial cure (under cure) is intentionally used when you want to add additional coats of polymer so the base coat will flow and stick to the additional coats. However, an partial cure is undercured polymer which can still flow and set to a barrel, not what you want the final coat for bullets, regardless of what you see on You Tube. So what he needs is something to either dissolve now cured powder coating or get under and loosen it.

[SwampShooter]

ShooterAZ, JB Bore paste arrived yesterday and that has taken all but a few vestiges of fouling out. I'll get the rest before I shoot again.

[SwampShooter]

Smoke, thanks for the heads up, I'll put that on my shopping list.

Edited to add that the powders are working very well, even the flat black. I just need to tweak my equipment design some in order to be able to compensate for density diffferences in the different powders.

[SwampShooter]

Dragonheart, I'm using a pyrometer with a new thermocouple that I have checked the accuracy of against known thermometers and water ice/boiling water etc. I'm hitting my temp and staying above. My average temps are 430-440 *F and my lowest temp is around 410 *F for the duration of the bake. I'm reasonably sure the coating is curing because of that and also because I'm not having this issue with 9mm (same powder/propellant/alloy). I think my problems are because of gas cutting due to bullet diameter, or too hard of an alloy, or too low of a propellant charge. It may be a combination of the three. On the other hand I'm not going to rule out a lack of cure just because when I do things like that I tend to make a fool of myself more frequently!

Edited to add more...

[SwampShooter]

igolfat8, I'll tuck that away for future reference.

[Dragonheart]

If your PC substrate temp has stabilized at 400 degrees and it cooks for 10+ minutes at that temperature that will cure the vast majority of powders. All the electronics are great, I love technology, but when it comes to monitoring temperature give me an old glass mercury thermometer and I am happy.
Hard alloys are a mindset of the old lube days and just not needed with powder coating, especially handguns. I have run pc pure lead at 1400 psi with no ill effects. In fact I now cast pure lead for my hollow points. I have slugged all my bores and I don't size more than .001" over my bore's groove diameter.
These are things that work for me, maybe they will help you.

[igolfat8]

I have run pc pure lead at 1400 psi with no ill effects.

1400 psi or 1400 FPS?

[Big Boomer]

Dragonheart: Did you mean 1400 psi or fps? I get fps but not psi. Big Boomer

[skeet1]

I think I will stick with my lubrisizer and Carnuba Red.

[SwampShooter]

I agree, a "real" lab bulb thermometer is my preference as well especially in well a lab. I am however used to using the electronic stuff in kilns and furnaces so I'm pretty comfortable with them. Mercury is still the best that is for sure, alcohol is just as accurate but I invariably will get air bubbles in them and I don't currently have access to any liquefied elemental gases to fix them. I have not yet modified my convection oven so no holes for a thermometer and to be honest with myself in that environment if I'm involved I will be down one glass thermometer before the day is done. First mod is going to be the addition of a dense mass in the bottom of the oven to serve as a heat sink. The ultimate goal is to make an oven that the oven is lifted up off so down the road narrow based bullets can be set in place and don't need to be moved before curing. I might also make a pass through type oven for broad based bullets. Too many ideas, not enough time...

I agree that my alloy is probably too hard or I'm not pushing the bullets hard enough. Right now I'm using 50/50 COWW/SOWW. The problem is my lee mold is dropping bullets that are small enough that before coating I'm not getting a nice shiny band all the way around them if I size the before PC. There is a reason that Lee molds are much less expensive. After PC the sizing marks go all the way around. The closer I get to pure lead the smaller my mold is going to drop and that could be more of an issue. I am anticipating having to polish the mold so I can get another .001-.002". Since I'm new to bullet casting, I'm trying to make one change at a time and manipulate the variables that don't make a permanent change first (read that as I'm not messing with stuff I can permanently screw up until later). Since I already have a bunch of bullets cast with this alloy I'm going to push them a little harder first to see if that makes a difference. While I like climbing trees, there is no reason not see if the low hanging fruit works after all! I like easy some days. Next I'll open up the sizing die. I'll melt the bullets down and use the alloy for something else and go to a softer alloy for this if that doesn't do it.

FYI everything has passed crush and cube tests. The coating will pull apart and expose lead where stretched too far but no lifting or flaking. That is why I'm thinking it's not a cure issue.

[Dragonheart]

Dragonheart: Did you mean 1400 psi or fps? I get fps but not psi. Big Boomer

1400FPS. Sometimes the old brain doesn't engage and something familiar pops up in its place.

[Dragonheart]

FYI everything has passed crush and cube tests. The coating will pull apart and expose lead where stretched too far but no lifting or flaking. That is why I'm thinking it's not a cure issue.

The next test is the scrape test. Take a razor knife and do a 90 degree scrape on the polymer to check the hardness. If the polymer scrapes off easily then it is not hard.

[popper]

50/50 COWW/SOWW Try COWW only. Gas cutting (burning) PC leaved a VERY hard residue. Acetone doesn't seem to cut it. Til you get it figured out, overcoat with BLL or LLA or something that will leave a coating on the barrel so the junk isn't so hard to clean.

[SwampShooter]

Hadn't tried scraping, I'll give it a shot.

[SwampShooter]

Popper, are you saying I should cast harder? Not a bad idea about tumble lubing till I get it figured out. You and kidding about hard, now I know what my dentist must feel like.

[popper]

Yes. I shoot XDM, soft works but can really leave a mess. Shot like 10 hitek coated on 30/30, had to use 3 50cal dry patches on the end of a coated rod, pounded with a big hammer to get the hard plastic donut out of the muzzle. Was building a BO pistol, tried using the BCG from the carbine that I shoot a lot of coated cast. Couldn't get the bolt to close. Long story but had to use a twist drill (by hand) to cut the junk out of the gas key. Normal PC residue in barrel is easy to remove but once it is burned, like concrete and solvent don't work.

[ole_270]

The next test is the scrape test. Take a razor knife and do a 90 degree scrape on the polymer to check the hardness. If the polymer scrapes off easily then it is not hard.

Just tried this on two different powders on three different bullets. With a pocket knife held perpendicular to the axis of the bullet, the coating scrapes easily to and into the lead. Fairly soft lead alloy that shows no fractures or flaking when crushed with a 3 lb hammer. The 25-20 and 38-55 are working fine, the 45 acp is causing some trouble and recovered bullets have a lot of coating missing. I just figured i had used too many bullets on a tray and didn't get fully heat soaked. I don't normally put near as many of the 250 gr 38-55 bullets on a tray since I like to stand everything up. The squatty 45s make it easier to balance the bullets while loading the tray into the oven. I do use an oven thermometer.

[Dragonheart]

Just tried this on two different powders on three different bullets. With a pocket knife held perpendicular to the axis of the bullet, the coating scrapes easily to and into the lead. Fairly soft lead alloy that shows no fractures or flaking when crushed with a 3 lb hammer. The 25-20 and 38-55 are working fine, the 45 acp is causing some trouble and recovered bullets have a lot of coating missing. I just figured i had used too many bullets on a tray and didn't get fully heat soaked. I don't normally put near as many of the 250 gr 38-55 bullets on a tray since I like to stand everything up. The squatty 45s make it easier to balance the bullets while loading the tray into the oven. I do use an oven thermometer.

I am sure you already know this, but make sure your bullets are out of the mold clean before coating.

You will find some powders to be better quality and some harder than others, but they shouldn't scrape off easily. I don't know who came up with the smash test, but it is a great idea to test the elasticity and bond of the powder, but it doesn't tell you everything.

I will take the credit for being the first to post the "Scrape Test" to this site, but actually Charlie Darnall designer of the FreeChex gas Check making tools came up with the Scrape Test idea to test the hardness of some of the powders we were using. It is a quick and simple test and will definitely show up a soft coating.

If you have a good thermometer that is proven accurate, then you know when the oven gets to 400 degrees the only problem is a loaded oven may take some time before the bullets get to 400. The timing for the cure starts when the bullets get to 400, so better to give them more time than not enough. I typically cook 1K+ at a time. These handheld infrared thermometers I don't have a lot of faith in, but they are better than nothing for a quick check of the temperature of the bullets before starting the timing.

[ole_270]

Question- since these bullets may be partially cured, could I recoat and bake again? The powder I'm using is PBTP Gloss Black wet, and the gray that Randyrat had. Thinking about getting some of Smokes clear to overcoat.

[Dragonheart]

Yes, if the coating did not get a full cure you can cook again. Doing what is called a "partial cure" is a way professionals get a thicker coating. You just do a coat the stop cooking after the first coat starts to flow then add a second coat and full cure. Of course if there is a problem with the powder of contamination it probably won't fix that, but I would give it a try.

[Bama]

Another item might help. A few rounds of jacketed will also make cleaning go faster. Some colors seem to be less of a problem than others also. In my evaluations Smokes "Bacon Grease" seems to be the best with mininum buildup and longer substained accuracy than any I have tried. I usually shoot 50 to 100 at a range sesion. A few brushes with Bore Tech and soaked patches usually makes quick cleaning.

[Newboy]

The powder does NOT have to be under cured to leave the hardest **** in a barrel I ever tried to get out. I never found a solvent to work on it. My barrel happened to be very hard, so I got a stainless brush and finally got it out.

Started expanding brass to .357, and sized to .358 (9mm), and problem went away.


Sent from my iPhone using Tapatalk Pro

[Petander]

BORE TECH ELIMINATOR is the product you want for pc residue removal

Yes it luckily is.

An occasional "undercure disaster" isn't that bad anymore. You can guess how I know. :)