10mm leading issue

[Arrow]

I shoot a glock 20 and 29 both with kkm barrels. I am casting with a mp 200 grain Cramer pin mould sized to .401". My notes are .400". I have tried wheel weight alloy, 1/2 ww 1/2 pure, and 2 part we 1 part pure. I have tried unique, tightgroup, longshot, and 800x. I even tried some aluminum plain base gas checks. These barrels still lead like hell. I have tried light medium and hot loads. I have pulled loaded rounds and measured to see if the bullet is getting swaged down and they are not. The only thing I can think of is I need a .402" or .403" bullet but then it won't chamber in my barrels. Any ideas?

[725]

Change your lube. Don't drive them so fast.

[Bzcraig]

Have you slugged your barrels? If not, do so otherwise you are wasting time. In the overwhelming majority of cases it is undersized boolits to blame.

[Sig]

I size to .402" for my P226 in 40S&W & they chamber fine. YMMV

[Bodean74]

Im still working on the same problem I need to do the same, I remember reading on slugging I need to find it again.....20sf lee 175 truncated, tumble lube/alox minwax stp

[Love Life]

How did the bullets perform in the factory barrels?

Try water quenching or heat treating/water quenching. 9mm and 40/10mm tend to enjoy a bit harder boolit. This is of course assuming you have slugged your barrel and you are sizing to the right size.

[Bodean74]

I quench coww 2% tin only shoot in my lonewolf 6.02 still looking how to slug

[Love Life]

How to slug is easy:

1. Ensure firearm is unloaded
2. Disassemble pistol and remove barrel
3. Run an oiled patch down bore
4. Take a pure lead something (roundball, boolit, fishing weight) that is larger than the diameter of the barrel.
5. Place lead something on barrel (or in chamber leade if you please)
6. Get the lead something started into barrel (do not use a wood rod!!!!)
7. Grab a handy brass rod close in diameter to the bore and use it to punch the lead something through the barrel and out the other end.
8. Ensure you catch the lead something on something soft or in your hand
9. Measure with a micrometer
10. Size future boolits accordingly.

[Arrow]

I have slugged my barrel and it was .400". I have tried carnauba red and lyman moly lube. I have tried light loads all the way up to hot. I don't understand what is wrong. I have tried everything I can think of and can't figure out these 10mm's.

[Bzcraig]

Ok, what are you measuring with micrometer or caliper?

[Bodean74]

Forgive me arrow for jumpin on your post.... so I did slugge I am sizeing to .401 and my barrel is at .401 thank you LoveLife and Bzcraig headed to midway to place order, Slow down speed racer what do you guys recomend .402 or .403

[Bodean74]

Arrow I will post the results asap .....coww/2% tin with correct sizeing

[Love Life]

I would recommend .402 and water quenching. Use a good lube.

[Arrow]

I have also tried water quenched. I measured slug with a micrometer. Bullets sized at .401 already have a hard enough time chambering. (Multiple rounds won't fully chamber) if I were to size to .402 or .403 there is no way they would chamber. I do feel like a bigger bullet would be my solution though.

[Love Life]

Have you fired any ammo through the Glock factory barrels yet?

[Bodean74]

I was having problems with feeding I now use a full case sizing die and factory crimp, smooth loading now ...also it looks like a .402 die is special order 60 day wait. I found some videos on how to hone my lee .401 looks eazy

[Love Life]

Honing the lee die is easy. Go slow and check as you go along.

[Bodean74]

Lovelife I see Arrow posted 50% cow 50% pure do you think that is to soft

[Love Life]

I'd water quench. Change one variable at a time and test. If his slug is .400, and he is sizing to .001 over then he should be in the relative safe zone for size so I would look at water quenching 1st (since he can't size larger due to chamber dimensions) and give those a go. If that helped, or didn't, then I would look at the lube, but Carnauba Red is a very good lube...

It also depends where his leading is in the barrel. If it is throughout the barrel from the beginning to the end then that would indicate a size issue with some flame cutting, skidding, etc. If it is only at the muzzle end then that would indicate a lube failure or possible constriction, but more than likely a lube failure.

Then there is the possibility of the barrel needing to be throated if it has a sharp throat. This could shave the boolit and leave to shenanigans. However, he did not mention seeing lead rings in the chamber.

You have to approach the 9mm, 40, and 10mm with a bit more focus due to the pressure of the rds. I have asked how his factory barrels shoot, and I am hoping to get the answer to that.

[Love Life]

I just checked my reloading notes for 10mm. Across 4 different pistol manufacturers, .402 sized, WQWW, Speed Green or Lotak Hard Lube or HI-TEK coating, all run full snort with no leading.

[Arrow]

I have shot the glock factory barrels and they lead too with this loads. They have sloppy chambers so I'm sure I can get them to run with a bigger diameter bullet. I am ultimately looking to use these kkm barrels with hotter loads for better case support. I have tried everything suggested on here to try by changing one thing at a time except for bullet size. The only thing j haven't changed is shooting a .402" or .403" bullet because they won't chamber in my barrels. What do I do about this?

[Love Life]

Nothing. Download the cartridge to 10mm lite levels and shoot them in the KKM barrels with match chambers or buy a boatload of plated bullets from Xtreme bullets.

[harley45]

Have you tried Powder coating? It was the only way I could get some of my molds to work in my Glock 10MM

[ctious]

Hey. Just seen this. I have been gone working my butt off. But. You should slug the throat area of the kkm. On mine the barrel is right at .400. But my throat is 4.025. I had to size up my cast perfect to get no leading. I also had to lap my chamber to allow extra room to chamber a .4025 boolit in the case. Once that was done I used steel wool to burnish the chamber. Also used the burnishing to take down the sharp edge of the throat area.

With that done you will need a m die, special made to expand the case to load the oversize cast without swaging it. Once you get that done you can load as hot as you want and it will be good. I have used white label. Tac 1. And homemade lube. All worked. Bullet fit is key. Also my lead is about 14 hardness. Water quenched. Mix of range lead with some lino. Dab of tin.



Feeding also improved when I burnished the chamber than polished.

The only crimp I use is to remove the bell. I don't crimp into the cast at all. With the proper m die it creates a ledge that the boolit won't go in beyond.

[leeggen]

Some really good advice so far, but does the glock have even number of riflings or is it an odd number? Makes a difference when micing the barrel slugs. Also if alot of jacketed has been shot through it then scrub the living daylights out of the barrel and get the copper/brass cleaned out, could be causing some soldering in the barrel. Just a couple more things to think about.
CD