Actually, If I'm at the range and I've shot a box or two of lead bullets down my CZ-82, I will usually end the session by firing 1-2 magazines of FMJ down the barrel. That tends to clean a large portion of the barrel out of the lead. Cleaning is so much easier. Now, if you happen to be the person who shoots 500-1000 rounds of lead through it without ever cleaning it, then i probably wouldn't go with hard rounds like FMJ or JHP until cleaning. But for shooting 50-100 rounds of lead, I purposely shoot 10-20 rounds of FMJ immediately afterwards to clean out most of the lead. mike...
Some years back there was a guy who posted on an online forum that he blew up a Glock by firing a one box (50 rounds) of lead (unjacketed) rounds down his barrel followed by a single FMJ round. It came apart on him when he fired the jacketed round. The pictures were sobering.
In the February 2010 issue of Shooting Times, there is an article by Allan Jones who has worked as a technician for Speer and did the editing and research work for some of their reloading manuals. He also has a rather long list of impressive credentials that qualify him as a serious firearm/ammunition/reloading expert. He writes that shooting jacketed bullets down a leaded bore is "A Big 'No-No'". The article is in the "Going Ballistic" Column and is entitled: "The Lowdown on Lead Fouling". The applicable text is quoted below.
"How many times have you thought it easier to shoot the lead out with a jacketed bullet? Well, don't even think about it. In extreme cases, this can cause irreparable damage. I've seen revolver barrel throats deformed and thin-walled barrels bulged. Either means a new barrel."
Beretta warns against the practice in the manuals of several of their semi-auto pistols. The text of the warning follows. (By the way, Beretta firearms use conventional rifling, not polygonal rifling--this isn't just a polygonal rifling issue.)
DO NOT ever shoot cartridges with jacketed bullets through a barrel previously fired with lead bullets before the bore is thoroughly deleaded.
Obviously some folks get away with this (I did it a few times without incident when I started my shooting career before I began finding warnings against it) but it is a practice that has a potential to cause damage to firearms and possibly even injury to the shooter.
It just occurred to me to ask about plated bullets, such as Rainier's and Berry's, they are softer than traditional jacketed bullets, right? The Rainier site advises to use lead bullet load data, but makes no mention of polygonal barrels.
One of the researchers who publicized the polygonal rifling/lead bullet issues was a forensic engineer named Mark Passamaneck. After blowing up a Glock with lead bullet reloads he did some fairly extensive pressure testing. His conclusions were that shooting even very hard lead bullets resulted in a measurable pressure increase with each additional round fired in a shooting session.
He stopped shooting lead bullets in guns with polygonally rifled barrels based on the results of his research but he indicated that he still shot plated bullets and didn't have any problems with them.
Just be careful. One of the worst cases of leading I ever experienced was the result of some low quality plated bullets. The plating was very thin and the lead underneath was dead soft. The plating was totally insufficient to do anything other than make the fouling a little harder to remove. So plated bullets should be ok, but check anyway when you first start using them to make sure that they're holding together and not causing leading in the bore.
