Being a long time caster, an early interest in the Glock pistols, and living close to the Glock U.S. headquarters; AND, worked for an agency that issues Glocks, I was privy to some of the early incidents that involved lead bullets in Glocks.
Firstly, the first 4 generations of Glock barrels have the polygonal rifling. It wasn’t anything new, but Glocks application to pistols was new. Gen 1-2 had feed ramps 5hat didn’t completely support case heads.
The problem wasn’t entirely with the barrels.
It was the ammunition.
Federal had a 9mm and .40 loading in a promotional line (American Eagle) as well as Georgia Arms. These used swaged lead bullets and a dry lube. Combined with being slightly undersized to properly fill the grooves of the rifling the ammunition leaded badly, particularly in the lead or throats.
If cleaned frequently, problems were averted, but in high volume training environments, such often wasn’t observed.
One of my coworkers experienced a discharge that resulted in a case head failure while attending academy training. He wasn’t hurt badly, but required first aid for a cut from the extractor being blown from the gun. Required stitches. Gun was damaged beyond repair. A law suit between the agency/state and Glock ensued. Neither acknowledged culpability, but from then on, only new, jacketed ammo was issued. Glock donated some guns and assorted gear. The ammo was quality “remanufactured” ammo by a local concern; they donated replacement new manufacture jacketed bullet ammo. Glock re-emphasized NO RELOADS , added LEAD BULLETED ammo to warranty warnings.
I’ve shot thousands of cast lead bullets through my Gen 2 .40. (Same serial# run as previously mentioned pistol). No problems.
But, I clean my barrels/chambers frequently. And I size my bullets to .402” and use an effective lube.
25yrs later, my pistol now sports a BCA drop in barrel. Different feed ramp, throat, and rifling.
Like a previous poster, my gun was a 6-8” shooter at 25yds. The last time I shot it at the range with my .402” cast bullets, over 4.0gr of Bullseye, they shot ~2.5”-3” with the BCA barrel. A VAST improvement.
I think I paid $43 for my BCA barrel when they ran a sale...
I’ve shot some coated bullets but don’t see them as a panacea. The coating is as hard as lead (or harder) but can be scraped off and combined with combustion residue can equally foul a chamber as to cause bullet set-back or firing out of battery enough to permit case head blow out.
Your gun, you ammo, your choice. I advise closely inspecting and or plunking your ammo. And, run a brush occasionally through the bore.
