Strange problem encountered with PD'd bullets

[Boarderguy83]

Hello all, I have encountered a problem that I have not heard of anyone else experiencing. I have been shooting PC'd bullets for about 2.5 months, and have had great results with them in several competitions so far. I am shooting them from a G19 with a lone wolf barrel. The problem I have encountered is that the rifling just after my chamber seems to be eroding. At first I thought this was just a large amount of freebore that I hadn't noticed yet in any of my previous cleaning sessions, but after several other shooting and cleaning sessions, it appears that the rifling has eroded more. I have a few pictures of what Im talking about. I have compared my barrel to several other glock barrels, and mine really does appear to have eroded a lot. On my last range session, last week, I noticed that a few rounds had started keyholing, this is something that I have not had happen to me yet with my loads in any of my 9mm pistols. I haven't noticed any rifling erosion in any of my other 9mm's, but admittedly I shoot my Glock A LOT more. I am not ready to say that the PC'd bullets have caused this or not, but I wanted to know if anyone else had experienced anything similar to this in any pistol EVER. Any help with this would be appreciated.

This is a picture from the chamber looking out to the Muzzle. You can see that after the end of the chamber that the case mouth indexes on, there is a very LARGE amount of freebore before the bullet starts to make contact with the rifling.

This is a picture from the Muzzle looking in toward the chamber. The erosion can be seen here too.

[popper]

What was it before you started using PC and what powder do you use? Can you compare the original and 'now' slugged bore/groove? Really going to have to document the claim that PC wears the barrel faster than jacketed.

[Doc Highwall]

My opinion is even though the powder coat is not hard is that it is abrasive and you are essentially fire lapping the barrel with each shot. Just my opinion now mind you.

[xacex]

I would have to ask several questions about what I see there. Specific powder used, specific P/C used,hardness of the material of the Lone Wolf barrels,approximate round count, to mention a few. I was looking at a MSDS, and most of the opaque colors have titanium dioxide which could be abrasive. Thanks for sharing

[ebner glocken]

This is worth looking into futher. It may be the PC that is abrasive. What feels slick in your hand might be abrasive when slammed through a barrel at high pressure and velocity. I don't know how many rounds you shoot through your glock in 2.5 months but I'm willing to bet it's plenty. If this is the case it's surprising that a guy shooting a 9mm would be the first one to notice, not the guy shooting a 30/06 @ 2500 fps. I have not noticed any erosion yet, then again I've shot only 10s of rounds.....not 1000s of rounds. You have my attention.

Ebner

[Boarderguy83]

Sorry for not including any info about my load. I'm using 4.7 GR of Unique under a cast and coated Lee 356-120 TC. I am using the black Harbor Freight PC applied with the ES gun, and sized after coating. Approximate round count with JUST the PC'd rounds would be just over 1000. Prior to shooting any PC'd boolits, I only shot plated bullets from Xtreme. As I said in my first post I am not willing to blame the problem on the PC just yet, but it does seem to be the only thing I have done different. I am going to put my stock Glock barrel back in and keep this "test" rolling. Thank you for all the replies.

John

[xacex]

That seems like a real low round count to do that kind of damage. I have that many through one of my 45's, but it is a slower round, and I did use other powders than just the black HF powder. I would suspect the black HF powder, or the barrel manufacture.

[popper]

Interesting you get keyholeing, which would indicate undersized or worn lands - not just throat wear. I've only used white & red, probably will trade the black for red if they'll let me. It probably has a carbon based color. Now you have to figure out how to measure the barrel to check for wear. I've used lots of unique for 40, no problem after thousands of rnds.

[leadman]

I am a guy that shot the 30-06 at 2500 fps. I don't know the exact round count but 50 rounds would be the tops. A big difference. I did not record before and after of the bore either.
What you could do is buy some Cerrosafe and do a cast of the chamber and throat area. Make sure to measure it as the dimensions change with time. I usually do an immediate measuring, then at 1/2 hour and 1 hour. Then continue to shoot it and measure it after a few hundred rounds.
The keyholing might indicate too small of a boolit. The cast would allow you to compare the throat to a boolit pulled from one of your cartridges.

[waksupi]

Please keep us updated on this.

[ffries61]

Glad this thread came up, I asked about the possibilty of barrel wear a few months ago in another thread, and the response I got insinuated I was an idiot for even asking.

Fred

[jcameron996]

I'm also very interested in this. I had been thinking I had found the answer to my 9mm leading issues. More study may be in order.

[MUSTANG]

I am interested too, I received 1 pound each of Harbor Freight PC in Red, Yellow, White and Black this afternoon from UPS. I had watched the variety of threads for a year and thought I was finally ready to jump in to coat and test some PC boolits. Now this thread makes me wonder if it was a case of "Ready, Fire, Aim".

[MUSTANG]

Duplicate Post Deleted.

[geargnasher]

The results of a few people using the HF powders so far in their pistols hasn't included much in the way of barrel wear reports, so this is interesting.

Those of us who have been discussing the potential advantages of PC'ing rifle boolits were very concerned with wear issues since the beginning, and I have even considered a test using a brand-new, "known soft", Savage factory .308 barrel to see if the concerns were warranted or not. I'm holding off until more results from the pistol shooters come in.

Thank you very much for the report, and please keep us posted.

I think most of the experience with coated boolits across the board hasn't been with HF black coating, so this may be an isolated case, or the barrel itself may be at fault and might well have eroded in a similar manner if you had used FMJ bullets. The keyholing is classic "oversized" barrel or "undersized" boolits, depending on how you look at it. Judging by the pictures, I am not surprised in the least that the boolits were beginning to keyhole.

Gear

[Magana559]

hmmmm

[freebullet]

What are the boolits being sized at & with what?

[Boarderguy83]

I am sizing all of the boolits to .356 with the lee sizer die after the powder coat cures. I have measure a ton of them with a dial caliper after sizing and they are indeed coming out at .356. I slugged my bore with a soft lead slug before I began any of the lead reloading, and found it to be .356. I know that a good rule of thumb is to go .002 over, but after also measuring some of the plated bullets that I used to use, they come out at .355, and I have shot several thousand of them through this barrel. To be fair, I had not checked for any erosion while shooting plated rounds, but honestly who thinks that the rifling in a pistol will erode while shooting any kind of jacketed ammo, especially at low velocity. I have only had the lone wolf barrel for about a year and a half, and I would never have believed that it would be possible to start eroding rifling from it in that short amount of time. I mean I could see if I were taking classes every week, or doing high round count competitions every week, but I'm not. I am putting the stock barrel back in, and will be shooting what I have left of the HF black PC'd boolits (that's about 700 rds.) to test and see if any of the stock rifling erodes. I wish I had the money to buy a new lone wolf barrel, as I would try it with a different color HF PC, and see if I get the same results, but you all know how that goes. Maybe Santa will get a visit from the Glock fairy, and bring me a new barrel for Christmas. I am not ready to give up on PC yet, as I love the process, and I love actually making my own ammo. Everyone that see's them is amazed that you can actually PC a boolit. Anyway, I will keep everyone updated on what comes of this.

[fastglock]

Yikes!!! very interesting thread I'm going to start inspecting my KKM & 300BLK barrels.

[runfiverun]

if there is titanium dioxide in the powder I can assure you it will sand down a steel barrel.
I use bright white printer paper containing ti dioxide to polish some of my rougher barrels out by fire-lapping with it.