NEW-----"scientific" info on HF black being abrasive

[bangerjim]

Well folks................this is probably about as close to "scientific" data as it is going to ever get on this ever-evolving grand experiment we are conducting with PC'ing booits. I developed this test this afternoon while inventorying my loaded rounds of PC'd ammo.

It appears HF has changed the supplier/formula for the matte black powder since I started doing this back in June or so. I noticed the older rounds were slightly "draggy on the fingers" to the feel and developed this simple test. You can do it also!!!!

Equipment required:
1) HF matte coated round(s), either loaded or not - any cal will work.
2) your clean DRY left hand
3) your clean DRY right hand

(cleanliness is next to Godliness............ and is VERY important for this test.)

Take either the boolit or the seated round in your right hand (left if you are south paw)
Place the nose in between your other hand's thumb and 1st finger, supporting with your middle finger. Squeeze down on it slightly.
Rotate the boolit back and forth for at lease a dozen cycles with your other hand.

Now look at it.

Notice any whitishness to the black boolit? If so, that is YOUR skin cells! Taken off by the ever-so-mildly-abrasive coating.

There you have it. The 1st repeatable "scientific" (?) test for HF matte black PC abrasion------- that everybody can see and do.

The boolits I tested were from a bottle of powder I bought waaaaaaaaay back in June. Others were from a bottle purchased in late Sept and they were NOT abrasive! Something changed in the HF powder.

I have bought 4 more bottles of black while it has been on sale but have not opened them. If anybody HAS used the new stuff.......please try this test and post the results. HF's stock has really been turning over------ thanks to us! The newer (Sept) stuff seems to not be abrasive at all and is more of a semi-gloss.

There are no lot numbers on the bottles to refer to.

I will shoot the over 400 rounds of various loaded cals up (some will be abrasive, some will not) and always check new coats in the future. I have several hundred unloaded boolits I will test shortly. If they are from the old batch.......thank God for do-overs! It burns right off in the pot.

I have shot hundreds up to now and have really not seen any definitive wear, but that is difficult to measure easily.

I use the matte black for a lot of other machine shop related coating things than just boolits, so no big whoop.

I am also using red, white, and yellow............all of which seem to have no abrasion due to being glossy.

I hope this helps y'all out and eases all those troubled minds out there that "just knew" that darned black PC was eating their guns alive.

banger

[kbstenberg]

A comment please.
The bore of the rifle is only contacted by the area of the bullet that was sized. How abrasive is the full diamiter of the bullet?
I would think that sizing would eliminate some of the abrasiveness. Kevin

[bangerjim]

Ahhhhhhhhhh.......therein lies the devil in the works!

We really do NOT know if there is enough abrasiveness from the contact with JUST the tops of the grease grooves to cause any significant wear over a long period of time. The nose had better NOT be bouncing down the barrel..........or you got bigger problems than a little black PC! If sized correctly to your bore, only the sides of the boolit, the tops of the grease grooves, should be in contact.

We do know that there is absolutely NO PC (of any color) left in the bore to cause a buildup of "stuff".

I bring this little discovery & test above to light so others can expound on their thoughts and findings. And have a way to check their product if they are concerned about the matte black.

Even if the sizing smashes the coating down (it does become shiny most times) does it eliminate the abrasiveness? Inquiring minds want to know!

And there is still no proof (+ or -) that the gloss coating do not have an abrasive effect either. This is a new endeavor for all of us and only Father time will answer all.

banger

[MacFan]

Hmmmm, the old saying "Smoother than a baby's butt" comes to mind as another traceable laboratory standard for a scientific test.
Could get you arrested though.
Good work Banger.

[Oreo]

The definitive test is to make a cast of the throat and another of the muzzle end of the bore. Then put 5-10k rounds of one particular kind of powder coat through the gun. Make new casts and compare.

[WallyM3]

I tried to think through the abrasiveness question and it made my brain hurt. But before I went for the Scotch bottle, I made note of the thought that perhaps the passage through a sizer might burnish the surface smooth.

It would really be good to know what the stuff is made of (as in MSDS?).

[MUSTANG]

I tried to think through the abrasiveness question and it made my brain hurt. But before I went for the Scotch bottle, I made note of the thought that perhaps the passage through a sizer might burnish the surface smooth.

It would really be good to know what the stuff is made of (as in MSDS?).

I gathered MSDS's from Harbor Freight and posted them here.

See Posts #60 and Post #62 at: http://castboolits.gunloads.com/showthread.php?222947-Strange-problem-encountered-with-PD-d-bullets/page3 (http://castboolits.gunloads.com/showthread.php?222947-Strange-problem-encountered-with-PD-d-bullets/page3)

[WallyM3]

Looks like the black has "calcite", whereas the others do not.

[Sweetpea]

Seems maybe it is "rough" and not necessarily "abrasive"?

Would take quite a few rounds to determine whether or not it could harm the bore.

[WallyM3]

The magnified pic of it looks like table salt. A kind of clearish crystal.

[fryboy]

if one sizes them ( especially a few thou ... ) even without the added pressure from being loaded then in turn wouldnt they also re-size the sizing die ?

[VHoward]

if one sizes them ( especially a few thou ... ) even without the added pressure from being loaded then in turn wouldnt they also re-size the sizing die ?

This is what I was thinking.

[3006mv]

I cannot measure abrassiveness in my AR bbl.
I DO notice after sizing the black boolits they are shiny smooth.
so possibly less abrasive at this point?

[dverna]

if one sizes them ( especially a few thou ... ) even without the added pressure from being loaded then in turn wouldnt they also re-size the sizing die ?

Not unless the stuff was very abrasive. There was a gentleman who posted some goo stuff on this. If I recall, it is a cubed relationship wrt to velocity. So at the low speed we size at, we would not see much affect on the sizer dies.

Don Verna

[KYShooter73]

We do know that there is absolutely NO PC (of any color) left in the bore to cause a buildup of "stuff".


This is incorrect Banger. I know you can get PC buildup with HF Black shooting COWW + 2% Tin with 312-155 aluminum checked at speeds of 1800 FPS plus. I will be steering clear of HF black matte at rifle velocities.

[bangerjim]

This is incorrect Banger. I know you can get PC buildup with HF Black shooting COWW + 2% Tin with 312-155 aluminum checked at speeds of 1800 FPS plus. I will be steering clear of HF black matte at rifle velocities.

You are shooting sonic+ velocities. Most of us PC'ing are messing around with subsonics in pistols and rifles.

I have no data personally on high velocity rifle loads. There are some on here that say they get NO fouling from PC at high speed. Just going by what I have seen in my guns and other are reporting.....virtually ZERO fouling on lower loads.

I use commercial FMJ's on higher rifle velocities and do not use PC'd.

banger

[MacFan]

(Not quite on topic)
Geez, if you don't want to use HF black for bullets at least it's darn durable on old Yugo mags. Gonna buy some Teflon PC for the insides and followers. :)
94578

[dbosman]

I can see the headline now. He Teflon lined the magazine so the bullets would shoot faster and penetrate worsted wool vests.

[MacFan]

I can see the headline now. He Teflon lined the magazine so the bullets would shoot faster and penetrate worsted wool vests.

I'm scared that anyone on here knows what worsted wool is! :wink:

[KYShooter73]

You are shooting sonic+ velocities. Most of us PC'ing are messing around with subsonics in pistols and rifles.

I have no data personally on high velocity rifle loads. There are some on here that say they get NO fouling from PC at high speed. Just going by what I have seen in my guns and other are reporting.....virtually ZERO fouling on lower loads.

I use commercial FMJ's on higher rifle velocities and do not use PC'd.

banger

I have not seen any buildup at slower velocities. I suspect it's a number of errors on my end, fast twist rate, fast burning powder, oversized boolits, too soft an alloy. Those things all come to mind.

[KYShooter73]

Just to show what it looks like, and how I remove it. Barrel was cleaned with a bronze brush and cotton patches soaked in Ed's red until patches showed little to nothing. Bore was then swabbed with acetone to remove the oils. A powder coat remover was applied to the bore with a loose patch and waited 30 minutes. Followed by about 30 seconds with bronze brush, then another patch with Ed's red. This is the patch:

94625

[popper]

KY - was they bore shiny before you used the PC remover, and what remover did you use?

[KYShooter73]

The bore was shiny, but I could see something built up where the lands meet the grooves, and some other patches of darker material down in the groove. I used D-Zolve 1012, which is meant for use completely immersing the part to be cleaned. It don't seem to damage melinite barrel finishes, and seems pretty weak, requiring numerous applications to get it all out.

[quietmike]

I'm scared that anyone on here knows what worsted wool is! :wink:

That's the real cheap itchy kind isn't it?

Nevermind, that's the worstest wool.

[Maximumbob54]

That's the real cheap itchy kind isn't it?

Nevermind, that's the worstest wool.

I think that's the stuff those old GI blankets were made of that we had to use in boot camp up in Great Mistakes, IL... ;)