Powder coating barrel residue ?

[BUFFALOW RED]

So I've been shooting for a powder coated Blue color 180 grain wheel weight casted bullets in my 40 Smith & Wesson about 300 rounds, approximately 950 fps, went to clean it and there was excessive black residue in the barrel grooves that took a lot of effort to get rid of no lead but I was shocked at how much this black hard so it was stuck to the inside of the barrel anybody else experience that maybe I'm not heating enough temperature I don't know

[GregLaROCHE]

PCing shouldn’t leave any residue. Make sure your oven is hot enough and you’ve backed long enough. Not all powders are the same.

[Wheelguns 1961]

The only time that I ever got any residue in my barrel, my bullets were too small. There was a tiny bit of lead that could not be seen until it was removed from the barrel.

[Smoke4320]

Usually 1 of 2 things
1. did not cure at an actual 400 degrees or for long enough at 400 degrees
2. bullets slightly undersized for bore

[BUFFALOW RED]

Ok thanks I'll check it. Probably rebake what's left

[BUFFALOW RED]

So how long at 400 degrees? I'm using smokes powder.
I not had this problem with my rifle using this powder. Barrel slug next.

[murf205]

So how long at 400 degrees? I'm using smokes powder.
I not had this problem with my rifle using this powder. Barrel slug next.

I bake @ 390-400 for 20 min.. The best small money you can spend is for an accurate thermometer. The dial graduations on toaster ovens are famous for not being close to the temp they indicate.I use a Cooper and it appears to be spot on as checked with 2 others. I have shot a ton of Smokes powder and had nary a trace of residue that wasn't gunpowder.

[BUFFALOW RED]

Thanks for info

[charlie b]

Never will understand why some folks won't bake long enough at the proper temp.

Use the mfg recommended time/temp. They spent a lot of money to come up with those numbers so I suspect there is a good reason for them.

[BUFFALOW RED]

I have smokes sample pack it came with no manufacturer name or instructions

[mehavey]

In General....

At least 30 minutes . . .
at 400-410° measured with reliable digital thermometer . . .
in a pre-heated oven . . .
. . . from the time you put them in.

If you are doing a large thermal mass amount of bullets (more than 1 - 1.5lbs) double the time

[Wheelguns 1961]

There was a good tutorial by Smoke on here somewhere. I can’t seem to find it now. I bake mine at 400 degrees for at least 20 min. Larger bullets get 25min. I do large batches at a time. I have a full sized oven used only for powder coating.

[charlie b]

I have smokes sample pack it came with no manufacturer name or instructions

Smokes has a recommended time and temp. 400F at 20min after it is up to temp.

[popper]

The PC residue (and there will be some dusty stuff, just abrasion) usually shoots out. Dark black stuff is from undercooking. You can't overcook the stuff time wise but higher temp will break down the poly linking -- bad.

[charlie b]

So I've been shooting for a powder coated Blue color 180 grain wheel weight casted bullets in my 40 Smith & Wesson about 300 rounds, approximately 950 fps, went to clean it and there was excessive black residue in the barrel grooves that took a lot of effort to get rid of no lead but I was shocked at how much this black hard so it was stuck to the inside of the barrel anybody else experience that maybe I'm not heating enough temperature I don't know

What does your bore look like after shooting jacketed loads?

[hc18flyer]

I use an oven thermometer, don't start my 20 minutes till I get close, back up to 400 degrees. If you have a large load, that can gobble up 10--12 minutes. I use Smoke's powders. hc18flyer

[Rapier]

I note that this post involves a 40 S&W handgun, brings to mind the differences in lands found in the 40 handguns and the care it takes to load and get good results in a polygonal rifled barrel. So the make of handgun is also important. For example Glock says not to use cast bullets in their guns because of residue buildup in their polygonal riflng. Some do shoot cast, with very hard cast, and get decent success.
The actual groove diameter the type of lands in the barrel, bullet hardness, bullet sizing, oven temperature and length of time of bake, all play a part in success.

[BUFFALOW RED]

What does your bore look like after shooting jacketed loads?

Never shot jacked in this gun

[BUFFALOW RED]

I note that this post involves a 40 S&W handgun, brings to mind the differences in lands found in the 40 handguns and the care it takes to load and get good results in a polygonal rifled barrel. So the make of handgun is also important. For example Glock says not to use cast bullets in their guns because of residue buildup in their polygonal riflng. Some do shoot cast, with very hard cast, and get decent success.
The actual groove diameter the type of lands in the barrel, bullet hardness, bullet sizing, oven temperature and length of time of bake, all play a part in success.

It's a Taurus mid 90's all steel 40 s&w, original owner claims he fired 1 box , didn't like the weight and recoil so it set in a drawer for 20 years till I got it. The black stuff hard to remove from groves.
Slugged barrel outside of slug measured . 401
Inside . 389
Im Sizing after PC with Lee . 401 sizer I fired 10 rounds with out sizing hard to get them in case and excessive recoil .
So I'm sizing all now.
THANKS for all your help

[Wheelguns 1961]

I would size them to .402”. Have you checked the actual size of the sizing die? I have found that many Lee sizers will size small.