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Warhorse
03-21-2008, 08:10 AM
Every lead 9mm bullet (125grn LRN-.356), that I load, leads my P239's barrel bad. I have varied the charge, and OAL to no avail. Is it possible that I am over crimping in my Lee FCD? If so, how can I tell?
freakshow10mm
03-21-2008, 08:30 AM
Don't use the FCD and see if that helps. If it does, the postsizing of the round in the FCD is most likely swaging the bullet down, causing gas cutting.
creophus
03-21-2008, 10:14 AM
Every lead 9mm bullet (125grn LRN-.356), that I load, leads my P239's barrel bad. I have varied the charge, and OAL to no avail. Is it possible that I am over crimping in my Lee FCD? If so, how can I tell?Like Freak just said it may very well be the Lee FCD.

Is it much harder to get the round in and out of that die? If so, you may want to stop crimping it.
918v
03-21-2008, 10:38 AM
Sig barrels lead due to their excessive throat diameter and their hammer-forged rifling. You might as well use .358" bullets, the barrel will still lead.
psyop
03-21-2008, 12:05 PM
Sig barrels lead due to their excessive throat diameter and their hammer-forged rifling. You might as well use .358" bullets, the barrel will still lead.

This has been my experience as well.
freakshow10mm
03-21-2008, 12:18 PM
How does hammer forged rifling effect leading?
918v
03-21-2008, 12:26 PM
The hammer forging process does not completely remove the tool marks left behind by the reamer used to ream the hole in the barrel blank. What looks like a perfectly smooth mirror finished bore is really a bunch of squished grooves and scrapes running against the direction of bullet reavel. They scrape lead off the bullet shank.

A broach-cut barrel has tool marks, but they run in the direction of bullet travel. They displace lead rather than scraping it off the shank. As a result, these barrels lead alot less.
chewy
03-21-2008, 03:54 PM
You could order one of them "Fire lapping Kits" from Midway to address the fine tool marks some. I firelapped my Taurus PT-92 factory barrel some time ago and compared to my new LWD G-35 9mm conversion barrel, the tauri one had no leading. maybe I just got lucky.
918v
03-21-2008, 05:00 PM
No, you actually changed the direction of the tool marks which makes all the difference.
Frost
03-21-2008, 06:08 PM
I am beginning to wonder if I made a mistake buying lone wolf barrels to use for lead.
RustyFN
03-21-2008, 07:00 PM
I use a FCD with lead in 9mm and haven't noticed any post sizing with the bullets I'm using. I don't crimp 9mm, I use the FCD to get rid of the bell that the expander die put in. These are from a friend cast from WW and I haven't seen any leading in my CZ.
Rusty
chewy
03-21-2008, 07:05 PM
I'm just gonna run a few various "grit rounds" through my LWD barrel and I'm sure that'll help it. I ordered the lapping compounds from Midway, not the lapped bullets, and apply it my self. Eh, it takes a little time, but I did it to my Marlin 1894 357 mag and get very little leading.
Warhorse
03-22-2008, 07:14 AM
Sig barrels lead due to their excessive throat diameter and their hammer-forged rifling. You might as well use .358" bullets, the barrel will still lead.
Thank you. I had no idea why, but it was looking like I could not shoot lead in that gun. I've got some FMJ's on the way, and lead is history for this pistol, and also my 1989 stamped slide 226, which are my only 9mm's.
918v
03-22-2008, 10:02 AM
You could always get a Bar-Sto barrel...
fredj338
03-23-2008, 10:36 AM
I think it may be you FCD. I taper crimp all my pistol ammo. I run leadTC out of my P239 & G17 LW bbl. w/ min. leading.
918v
03-23-2008, 12:34 PM
My experience with Sig barrels is that they tend to lead the rifling immediately in front of the chamber. They all do this, including the P220 45 ACP.