Abrasiveness of PC bullets

[Alangaq]

Has anyone noted any barrel erosion from the use of PC bullets that may be indicative of the coatings possessing an abrasive quality? With the number of threads dedicated to this process, I would think that if there were a problem with these bullets causing accelerated wear in the barrels that it would have been noted and documented by now, but still I am curious and have not read anything one way or another on the topic.

[Oreo]

There's only been one guy with a problem afaik. The rest is all speculation and some educated guesses.

To get a definitive answer would take chamber casts and muzzle casts of before and after several thousand rounds using only one particular type of powder (coat). Then a reasonable assessment could be made of that particular powder.

[Wally]

If the PC contains Titanium Dioxide, it is highly abrasive. Just wash a wall of flat paint with a rag..it will shred it very quickly...

[lka]

I just put my 6th set of 100 (600) through my sr40-c and haven't noticed any issues yet, I'll keep puttin them through it and maybe one day I'll need to buy a new barrel. I can't think of an easy way to get a definite answer. I've been very happy with PC, it definitely adds a new fun twist to loading.

[KYShooter73]

I was the guy with the problem, burned up first 5 inches of a barrel in less than 500 rounds. I'm still not sure that PC was to blame. I have half a dozen different possible ideas as to what caused it, using HF black powder coat was only one of my possible causes. It could have been any of the following or something else entirely.

1. The HF black I used contained or was contaminated with something abrasive.
2. I over cured my PC causing it to become abrasive.
3. Overpressure loads and using powders not recommended for the blackout.
4. Gas cutting around the boolit.
5. Lead that was improperly cleaned and fluxed by me possibly contaminated with FeO2.
6. Aluminum gas checks causing some problem.

Anyhow, those were my guesses.

[KYShooter73]

How is that a guess?

Because I do not know how using Benchmark powder, a somewhat slower powder than Lil'gun or Win 296, gradually increasing the load until the bolt cycled, and watching for primer signs or case damage, or using less than 1 gn over of Lil'gun that slightly expanded a few primer pockets would cause the lands to erode significantly enough to scrap the barrel. Can you explain?

[bangerjim]

There is always someone that questions this ever so often. But to date there are probably thousands of us shooting perhaps 100's of thousands of rounds of PC'd boolits of various cals and loads.....and none have had ANY problems! And it sounds like KY has some "other" problems than the PC.

I would not be afraid it! I coat and shoot tons of them with no noticeable problems.......except NO LEAD and CLEAN BARRELS. Wait......those are not problems!!!!!!!

If you are paranoid about PC'ing, avoid the HF matte black. It is still my favorite color! There is no credible info anywhere that there is any detrimental with it or any of the other many various powders people use.

banger

[KYShooter73]

It's too cold for me to PC right now, but as soon as it warms up I'll be back at it. I'm going to finish out my HF black on pistol bullets, and switch to a different powder for rifle. My wife and I have fired 4 or 5 thousand pc'd pistol boolits without a hitch.

[bangerjim]

It's too cold for me to PC right now, but as soon as it warms up I'll be back at it. I'm going to finish out my HF black on pistol bullets, and switch to a different powder for rifle. My wife and I have fired 4 or 5 thousand pc'd pistol boolits without a hitch.

I feel for 'ya on that cold weather!

And thanks for sharing your info on the pistol rounds.

Hope you figure out what is/was going on with the gun you originally had problems with. Let us know what you discover.

Any/all proof of performance of PC is more than welcome by all of us hooked on this method.

banger

[totalloser]

There was another thread I read a while back with dramatically accelerated barrel wear shooting PC. The barrel was a drop in conventional rifled in a Glock and the owner was sizing to .356" My suspicion after reading the thread is that the issue was sizing too small and that .357" should have been used.

With lubed boolits, if you size too small you get leading and are encouraged to immediately deal with it. But with PC if you go too small, there is really no symptom. And the same forces that cut the boolit can erode the rifling in the barrel.

The basic concept that is in play is that if the boolit seals the bore, the gasses expand, but do not flow over contact surfaces, thus their ability to transmit heat to the metals involved is quite minimal. Once there is a gap to flow through, gasses can accelerate past at *insane* velocities and impart dramatically more combustion exposure to the materials involved. Lead being weaker than steel of the barrel, lead "gas cuts" and turns into a headache LONG before any barrel damage can occur. But if this problem pops up with a PC boolit, the first symptom you would see is rifling and chamber erosion- and by then it's ugly.

I could be interpreting this whole thing wrong, but if I'm right, the solution is simple, and carries virtually no risk: Make sure not to use a boolit too small.

[lka]

I was also thinking, if it were causing damage then shouldn't they mess with our sizeing dies? I'm going to keep a close eye on the lube size dies.

[kryogen]

my ES PCed midnight black is so glossy I dont see how it could scratch anything. Like glass.

[bangerjim]

my ES PCed midnight black is so glossy I dont see how it could scratch anything. Like glass.

Well......the nay-sayers insist that any pigment in any coating will abrasive. Whatever.


banger

[w0fms]

Has anyone tried a clear PC yet? As for looks I'd probably prefer it.. but then again the HF PC is so inexpensive by comparison to everything else out there, maybe we will eventually have a definitive answer on what the best color is for wear in a few months!..

[Maximumbob54]

I'm still a bit at a loss from that flat black thread. Last I remember the "carbon black" in the powder was the culprit. How is this different than the carbon soot being ground into the barrel by copper jackets?

[lka]

Ok looks like I can cut out of work in an hr so my question,,

Any advice on testing abrasive ness? I'm thinking about putting a bullet into a drill and running it on certain material units either the material fails or the PC rubs off. I'm going to video tape the findings and post to tube

[Maximumbob54]

I know if I ES spray coat with the HF red then they like to jump from my fingers sometimes. That finish is super slick. The slick finish has had me curious about reducing charges or using a bit faster powders as several times I've had unburned powder that I'm not used to seeing.

[bangerjim]

Ok looks like I can cut out of work in an hr so my question,,

Any advice on testing abrasive ness? I'm thinking about putting a bullet into a drill and running it on certain material units either the material fails or the PC rubs off. I'm going to video tape the findings and post to tube

My test:

http://castboolits.gunloads.com/show...ght=scientific

Found early black ones were abrasive. Newer powders are not....at least to my "scientific" test!

banger

[bangerjim]

I'm still a bit at a loss from that flat black thread. Last I remember the "carbon black" in the powder was the culprit. How is this different than the carbon soot being ground into the barrel by copper jackets?

It is not the carbon black, it is the calcite and barite that could be abrasive. All the others have titanium dioxide for pigment which could be abrasive also.

That is what all the hoop-la is about.

Whatever!

banger

[Gremlin460]

I don't PC coat, I use HiTek. However, coating, copper,lead & lube, when 2 materials rub one on the other there will be wear, simple physics, Eventually we will wear out a barrel shooting it, I personally believe even if coating is slightly more abrasive loosing 12 month off a 20 year life span on a barrel is really nothing to cry about, when you consider the benefits of coating.
We coat, it works (which ever way you coat), if we trade a small % of barrel life in exchange for cleaner easier years of shooting, then by my vote so be it.
We know shooting wears a barrel, otherwise fire-lapping would not exsist.
But also in out favour if we wear a barrel .001 or. 002 over many years of shooting, so what, we just increase the diameter of our casts until we are shooting a smoothbore.
I am beting that to get to THAT situation is going to take much longer than most of us have left on this earth.

So does coating wear a barrel, yes it does, does it massively increase wear?, no one has seen signs of that.