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Cyterio
09-17-2011, 09:53 AM
Does anyone know of a lead alternative that can be shot out of an MK9? The reason I ask is that the indoor range I shoot at is lead only rounds due to their trap system. I can't shoot lead out of the MK9 because of the polygonal rifled barrel. I thought about purchasing a basic barrel for it, but would rather use the factory barrel to practice with and don't want to have to keep swapping barrels when going from inside to outside.

jocko
09-17-2011, 11:10 AM
I have no doubt you can safely shoot a 100 rounds of lead indoor and then come home and give the barrel a good cleaning. Lots of glock shooters shoot lead. I tend to think the lead caution on polygonal barrels might just be a tad over done, certainly a 100 rounds ain't gonna cause anythingj. Hell run a snake through the barrel at 50 rounds if it bothers you. Not sure but I would almost bet u can buy a cm9 barrel and it would work fine in the MK,

Maybe fine another range,as it is strange as most all ranges today outlaw lead due to epa reg, and local ordinances.

Cyterio
09-17-2011, 11:17 AM
Yeah I thought it was odd as well that it is lead only. As far as finding another range, there are a few other options, but their indoor is lead only as well. I live in western Pa and it seems that's the norm around here. I'm only looking for options because the weather will be dropping soon here and the indoor range is heated and open 24/7. I've read about copper washed bullets, I wonder if those would be an acceptable substitute. I'll just have to call the range office and see what recommendations they have. Thanks!

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jocko
09-17-2011, 11:19 AM
something to think about:

Barrels and Bullets: Conventional Versus Polygonal Riflingby Dennis Cantrell 06/08/2010 0
Comments The bore of a gun barrel with conventional rifling is etched with corkscrew-like cuts. Each cut, or groove, is separated by a ridge of metal called the land. Together, these grooves and lands define the type of rifling inside the bore. The height, width, and number of lands will vary by manufacturer, though most handgun bores have about six lands. All conventional rifling is formed by cutting or exerting pressure within the barrel, unlike polygonal rifling which is formed by hammering the barrel from the outside.

The word "polygonal" refers to having many sides and angles and is used to describe bores with unconventional rifling. While the lands of conventional rifling look somewhat like the angular teeth on a gearwheel, those of polygonal rifling look more like bulges rising from the bore. Polygonal rifling was an outgrowth of a cold-hammer forging process developed by German engineers prior to the Second World War​. The process addressed the need to produce more durable machine gun barrels in less time than those produced with traditional methods. Current manufacturers whose handgun barrels have hammer-forged polygonal rifling include Glock, Kahr, Magnum Research​, and Heckler & Koch​.

The advantages of barrels with polygonal rifling include a smaller gap between bullet and bore, leading to slightly higher bullet velocities, and smoother bores that accumulate less fouling, making them easier to clean. The barrels are also generally more accurate because there is less bullet deformation by the "grooves" (less "bite" into the bullet) and because the bore's surface is formed with more consistency. Because the rifling has no sharp corners to erode, barrels with polygonal bores have a longer, usable life, since they retain their accuracy longer. Finally, the hammer forging process used to create barrels with polygonal rifling is less likely to leave traverse tool marks, another cause of fouling, and a problem more common in conventionally rifled barrels. Accuracy, longevity, and strength may be the greatest practical benefits of barrels with polygonal rifling. A limitation is their inability to be safely used with lead bullets.

To understand why it's generally not a good ideal to shoot non-jacketed lead bullets out of barrels with polygonal rifling, it's first necessary to understand how a bullet passes down the bore. All bullets are slightly larger in diameter than their nominal caliber, which is defined as the distance between opposing lands. The bullets are larger in order to provide the "extra" metal that gets squeezed into the rifling by the propellant's expanding gases as the bullet travels down the bore; this extra metal fills in the grooves to provide a purchase for the rifling, thus allowing it to spin the bullet down the bore. Conventional rifling, developed when lead bullets were the norm and muzzle velocities somewhat lower, has grooves deep enough to accommodate the buildup of lead deposits caused by the friction between bore and bullet. Regular cleaning removes the deposits before they become constrictive.

However, because more of the bullet's bearing surface is in contact with the bore in polygonally rifled barrels, lead bullets, especially when pushed at high velocities, are literally squirted down the barrel, "smearing" the bore with a lead veneer. As this veneer builds up and fills in the gap that normally exists between the bore and bullet, it causes pressure from the expanding gases (now less able to pass through the gap) to increase dangerously. This is not a problem with jacketed bullets because the jacket material is a copper alloy that's much harder than lead and resists shedding.

In fact, the ability to use cartridges with non-jacketed lead bullets may be the greatest practical benefit of conventionally rifled barrels. If ammo is scarce and you can only buy or barter for cartridges with lead bullets, or you're a reloader who uses lead bullets to keep costs down, conventional rifling is an asset. Also, conventionally rifled barrels made of stainless steel, or that have been chemically hardened or plated with hard chrome, will have good usable barrel life.

Nevertheless, cold-hammer forged barrels with polygonal rifling are more durable, stronger, easier to clean, and retain their accuracy much longer than any other barrel. And, in a pinch, you can even shoot lead bullets through them, just not too many between cleanings. But since most cartridges for target and self-defense have jacketed bullets, this "limitation" of polygonal rifling is mostly theoretical. And the problem can be avoided entirely by purchasing a conventionally-rifled replacement barrel.

For someone whose practice regimen is an occasional trip to the range, the type of rifling doesn't matter since they will never shoot enough rounds to affect the accuracy of their weapon. But, for those who practice frequently, or who plan to compete in practical shooting matches such as IDPA or IPSC, a hammer-forged barrel with polygonal rifling will last longer with less maintenance

jocko
09-17-2011, 11:23 AM
here is another one to think about

Lead bullets and polygonal rifling
This section may contain original research. Please improve it by verifying the claims made and adding references. Statements consisting only of original research may be removed. More details may be available on the talk page. (September 2009)

The manufacturer Glock advises against using lead bullets (meaning bullets not covered by a copper jacket) in their polygonally rifled barrels, which has led to a widespread belief that polygonal rifling is not compatible with lead bullets. Firearms expert and barrel maker, the late Gale McMillan, has also commented that lead bullets and polygonal rifling are not a good mix. Some have made a point of the fact that neither H&K nor Kahr explicitly recommend against lead bullets in their polygonal rifled barrels, and feel that it is probable that there is an additional factor involved in Glock's warning. However, Kahr's FAQ does include a warning that lead bullets can cause additional fouling[7] and recommends special attention to cleaning after using them. In addition, while H&K doesn't warn against the use of lead, at least one well-documented catastrophic incident in an H&K pistol[8] may be related to this issue. Furthermore, Dave Spaulding, well-known gun writer, reported in the February/March 2008 issue of Handguns Magazine that when he queried H&K about their polygonally rifled barrels that they commented: "It has been their experience that polygonal rifling will foul with lead at a greater rate than will conventional rifling."

One suggestion of what the "additional factor involved in Glock's warning" might be is that Glock barrels have a fairly sharp transition between the chamber and the rifling, and this area is prone to lead buildup if lead bullets are used. This buildup may result in failures to fully return to battery, allowing the gun to fire with the case not fully supported by the chamber, leading to a potentially dangerous case failure. However, since this sharp transition is found on most autopistols this speculation is of limited value. The sharp transition or "lip" at the front of the chamber is required to "headspace" the cartridge in most autopistols.

Another possible explanation is that there are different "species" of polygonal rifle and perhaps Glock's peculiar style of polygonal rifling may be more prone to leading than the particular styles employed in the H&K and Kahr barrels.

Leading is the buildup of lead in the bore that happens in nearly all firearms firing high velocity lead bullets. This lead buildup must be cleaned out regularly, or the barrel will gradually become constricted resulting in higher than normal discharge pressures. In the extreme case, increased discharge pressures can result in a catastrophic incident.
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u will notE that most all of them say it can be more critical in a HIGH VELOCITY gun, now my question is to those more knowledeable would you consider the 9mm a HIGH VELOCITY GUN????

jmurch
09-17-2011, 01:51 PM
A 9mm is what 1300fps as a high average? A .223 and many other rifle cartidges are around 3K or 2+times as fast. My bet would be that 9mm doesn't qualify as high velocity.

And are we talking lead lead or hard cast lead:


Shooting cast bullets in polygonal barrels, by Tim Sundles, President of Buffalo Bore Ammo

(http://www.buffalobore.com/index.php?l=product_list&c=59)

True hard cast bullets (as opposed to lead swaged bullets) that are properly lubed will not lead foul polygonal barrels any more than any other type of rifled barrel. Ever since Glock Corporation warned to not use lead bullets in their pistols with polygonal barrels, a myth that hard cast bullets will lead foul polygonal barrels has become wide spread in some parts of the firearms world. However, the myth is untrue. Hard cast bullets are not "lead" bullets.

Pure lead or nearly pure lead bullets have a tendency to foul any barrel, not just polygonal barrels. Years ago, when several Glock pistols experienced cracked barrels because of fouling build up from shooting pure lead bullets, Glock issued a warning not to shoot lead bullets in their polygonal barrels. From that warning, the myth that you should not shoot hard cast bullets in polygonal barrels was born.
Provided you use real hard cast bullets with good lube, you can shoot them all you like in polygonal barrels without causing lead fouling deposits at the front of your chamber or anywhere else in the barrel. If you are concerned about lead fouling from hard cast bullets, all you have to do is to clean your barrel after firing hard cast bullets and before firing any jacketed bullets. However, in my experience, quality hard cast bullets won't foul a Glock polygonal barrel or any other type of barrel but lead bullets normally will.