Rifling cutting through PC coating, leading issues with PC

[RightAngle]

I ran two bullets through my barrel yesterday evening with a dowel to see how they came out. Been having terrible luck with leading.

They both had exposed lead where the rifling cut into them. Hammer test seemed fine. No lost coating.

I'm curious if the coating did not cook long enough to cure. Baked at 400 degrees for 20 minutes. in a toaster oven. Confirmed stable temp with thermometer before cooking.

I'll post pictures this evening.

Backstory: I've been trying to get successful at PC bullets for a while now. 9mm (I've read its the problem child). Bore diameter is .3555. Mold drops .358s I coat and size to .357.

Ordering a 38s&w expander to ensure the bullets arent getting swaged during seating as well.

Any other thing I might be missing?

[BigAlofPa.]

I had leading issues with Hi-tek coated bullets. It was the powder i was using. One of the manufacturers recommended powders below the top 15 on the burn rate chart.

[2wheelDuke]

I had leading issues with Hi-tek coated bullets. It was the powder i was using. One of the manufacturers recommended powders below the top 15 on the burn rate chart.

That's interesting. I've never seen that. I had issues with HiTek in a polygonal bore that I just couldn't get to run with cast.

I was using Bullseye, so that may have had something to do with it. I'll have to try some slower powder now that I'm on a Win 231 kick. I've still got some Hi-Tek coated bullets around too.

[Sig556r]

Not sure if it helps, but doweling a boolit thru a barrel may not mimic hi-velocity rifling pass.
If your hammer test indicate no PC peeling & your bore fit is tight, it may as well be that the boolit is being swaged during seating or crimping. Pull out a completed round & check the diameter if its still at least .001" larger than your bore. Also, ensure a clean barrel when you test fire.
Good luck

[Idz]

my 45acp soft lead with HF red PC occasionally showed some leading. What I discovered was the bullet was sometimes cocking slightly and scraping the PC off. My cure was to chamfer the case mouth and use a longer version of the M die to expand the case and ensure straight seating. Have you tried pulling a bunch of bullets to check the PC integrity?

[RightAngle]

Forgot to mention, using smokes powder, so I know it's high quality.

Also using titegroup.

[RightAngle]

Not sure if it helps, but doweling a boolit thru a barrel may not mimic hi-velocity rifling pass.
If your hammer test indicate no PC peeling & your bore fit is tight, it may as well be that the boolit is being swaged during seating or crimping. Pull out a completed round & check the diameter if its still at least .001" larger than your bore. Also, ensure a clean barrel when you test fire.
Good luck

Leading issue is why I doweled a couple through.

[popper]

What alloy? Assume 9mm, they have notorious bad transitions to the bore. If the lands have no PC and DO have a big 'tail' in the L.G. might size a tad smaller. Also depends on the load and powder. Fast powder and hot load can bump it up before it gets in the bore and cause cutting of the rifling vs 'flow' into the grooves (just like you pounding one in). Is it skidding in the grooves?

[BigAlofPa.]

The powder i was having issues causing leading was tite group. It was mostly with 9mm and 380. 45 and 40 not so much. I changed to Alliants sport pistol.

[RightAngle]

What alloy? Assume 9mm, they have notorious bad transitions to the bore. If the lands have no PC and DO have a big 'tail' in the L.G. might size a tad smaller. Also depends on the load and powder. Fast powder and hot load can bump it up before it gets in the bore and cause cutting of the rifling vs 'flow' into the grooves (just like you pounding one in). Is it skidding in the grooves?

WW alloy, I'm not sure if its skidding in the grooves.

Might need to try a different powder I guess. I have plenty of Unique and Bullseye. Would those powders work better than Titegroup?

[Burnt Fingers]

My Canik TP9SFX had no leade. The rifling was cut almost 90 degrees to the chamber. No matter what I did it leaded terribly.

I sent the barrel to DougGuy. Now there's no leading problems at all.

[mattw]

I would look that chamber over really well. If you have no leade, you will have a problem with shorter, lighter bullets. For example, a 147 may be trouble free but a shorter more dramatic TC may not transition well. I have had this problem with one of my 32ACP's, switching bullet profiles resolved the issue. I have not been able to find anyone that is willing to ream the leade into the barrel for me. Not a common reamer to have on hand.

[popper]

I'd give 4 gr. unique a try, its lots slower. Lets the bullet get into the rifling before kicking it hard. WSF or 231 might be another. If you are not water quenching after cooking, you must wait couple weeks for the alloy to harden.

[Conditor22]

Let's go back to the powder. Yes, smoke sells good powder.

First question how did you apply it and how thick a coat did you put on? [pictures would help]

Did they pass the smash test (hammer the boolit into a penny or a square and NO PC should flake or chip)



What temperature did you bake at?

Did you test your oven to see if it was actually reaching 400°? (almost all countertop ovens settings are off, some over 50° low) I test my ovens (that aren't hooked to PID's) every time the surrounding temperature changes ( I had to turn one up 20+°)

How long are you baking the PC for? Manufacturers specify XX minutes AFTER the boolit reaches 400° OR the PC starts flowing/melting. I've found that 25 min in a pre-heated convection oven that has a heat retaining material in it (I cover the bottom of my oven around the elements with ceramic BBQ briquettes others use fire brick, lava rock or? anything to hold the heat and help the oven get back to operating temperature faster)

Are you using a convection or toaster oven? Toaster ovens work but you need to bake small batches.

OK You answered these questions "Baked at 400 degrees for 20 minutes. in a toaster oven. Confirmed stable temp with a thermometer before cooking."

It's easy to overload a toaster oven and some take a loooooong time to return to temperature. I would strongly recommend getting a convection oven! I got 2 nice convection ovens at thrift stores (1 - $15 and 1-$20)

Pictures are very helpful.

I would start by making sure the barrel was clean. Bake a small batch (25-50) in your preheated toaster oven for at least 25 min and see what happens.

[cwlongshot]

I have been using tite group and a PC bullet in my 40 for two seasons now. Zero issues and actually squeaky clean!!

There are many variables. Id just be mimicking the guys before me. But real quick

Not all powders are the same. Not all colors from same manufacturer, are the same. But most MEAN the same thing...its X minutes at X degree. Its not the thermostat only. But the bullet itself, needs to hit that temp for that amount of time.

As I mentioned I have used it in competition so allot of rounds thru my guns. Different colors too so diff manufacturers of the powder. Still no issues. My vel are low maybe 1000-1050 ish. 3.8g is my load IIRC.

Something else I didnt see mentioned was your bore. It could be very rough. Has the gun been fired much? You might lap it with JB bore paste. I know that helps some of my jacketed guns with fouling.

Good luck,

CW

[fredj338]

I get more complaints about leading with TG users than any other, regardless of caliber. It is possible that the rifling in your barrel is rough & cutting the coating. Is it a new barrel? You may try smoothing it a bit by shooting 1000 jacketed or use some JB bore paste & give it a scrub. I run HT & PC coated in cut & button rifled barrels with no leading up to 1200fps or so.

[RightAngle]

Forgot to mention earlier, the leading is occurring towards the muzzle.

Gonna head out to my shop and snap pictures of the bullets shortly, and will answer the questions yall have asked.

[BigAlofPa.]

I was getting the leading too the last 3rd of the bore with T.G.

[tomme boy]

Also using titegroup.

That is your problem right there. TG just does not work for all peoples guns. Try turning up the temp on your oven just a little bit and bake them about 10 min longer. But I feel if you switch powder to charge them it will stop.

[Conditor22]

You said you just punched the boolits through the barrel with a dowel?
I hope it was a metal dowel. Preferably a brass rod, maybe aluminum or steel wrapped with tape to protect the threads.

Don't become complacent!! Yes, a wood dowel may work once or twice or? times BUT, if the wood isn't perfectly straight grain it could sheer in the barrel and the odds are good that it would take a gunsmith with a grease ram to press the wood out.