Polygonal Rifling In Pistols
- Thread starter Glenfilthie
- Start date
You won't find a consensus but I can tell you that I've personally put several thousand lead .45 and 9mm projectiles through a USP & P30 respectively with no issues. I much prefer plated or jacketed bullets but when the supply or cash is tight hard cast lead will do the trick!
I give the barrel a quick clean every 200 or so rounds. Never had any issues. If you run your gun with lead bullets for a long time without cleaning you could experience some nasty consequences like case ruptures.
NO YOU CAN"T, to quote Hungry on here, because your #### will fall off. I got over 3000 lead 200swc down the pipe of my HK Mark 23. 5000 rounds on a P9S I had from yesteryear. Still waiting for my #### to fall off.
Forest1488
CGN Regular
- Location
- South of Toronto
These words should be engraved on the side of every firearm.
Good stuff guys.
So...how's the accuracy with cast lead? Can you see any real difference? I use my USP45 Tactical as a bullseye gun because I am not a big IPSC fan and I am just pleased as punch with the gun so far in that role. Will lead open those groups up a bit?
So...how's the accuracy with cast lead? Can you see any real difference? I use my USP45 Tactical as a bullseye gun because I am not a big IPSC fan and I am just pleased as punch with the gun so far in that role. Will lead open those groups up a bit?
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. Neither H&K nor Kahr explicitly recommend against lead bullets in their polygonal rifled barrels, suggesting that there might be an additional factor involved in Glock's warning. Kahr's warns that lead bullets can cause additional fouling[8] and recommends special attention to cleaning after their use. While H&K doesn't insist on a copper jacket, at least one well-documented catastrophic incident in an H&K pistol[9] 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.
Source: http://en.wikipedia.org/wiki/Polygonal_rifling#Lead_bullets_and_polygonal_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.
Source: http://en.wikipedia.org/wiki/Polygonal_rifling#Lead_bullets_and_polygonal_rifling
Graydog and RAKS summed it best. If you do expereiencer leading clean it out as it will only get worse with each round fired. 100% Copper Chor Boy strands wrapped around a cleaning brush will have the lead out quickly with little effort. If the alloy in the bullet is right ie hardness relative to cartridge pressure and the sizing is right you should not see leading in most firarems.
Take Care
Bob
Take Care
Bob
Forest1488
CGN Regular
- Location
- South of Toronto
It's intelligent posts like this that show the great potential of a well run forum. Good stuff!
The Glock manual also contains a warning against using reloaded ammunition.
"The use of reloaded ammunition will void the Glock warranty, due to the unpredictability of the standards (SAMMI/NATO) adhered to, since reloads of poor quality ammunition may not meet (SAMMI/NATO) specifications, may exceed limits, and therefore may be unsafe."
Of course no one shoots reloaded ammo in their glock
"The use of reloaded ammunition will void the Glock warranty, due to the unpredictability of the standards (SAMMI/NATO) adhered to, since reloads of poor quality ammunition may not meet (SAMMI/NATO) specifications, may exceed limits, and therefore may be unsafe."
Of course no one shoots reloaded ammo in their glock
The Glock manual also contains a warning against using reloaded ammunition.
"The use of reloaded ammunition will void the Glock warranty, due to the unpredictability of the standards (SAMMI/NATO) adhered to, since reloads of poor quality ammunition may not meet (SAMMI/NATO) specifications, may exceed limits, and therefore may be unsafe."
Of course no one shoots reloaded ammo in their glock
So does every gun manufacturer. Lawyer material IMO; they just want to protect their asses...
Some of which has a kernal of truth. Copying portions of an article from Wikipedia which is light on content hardly makes it a great post. FYI my Tanfoglio polygonial .40cal barrel has never exhibited any leading in over 8K rounds. There are shooters on the cast bullet forum who have thousands of rounds through their Glocks with no problems due to leading. They do clean their guns after each range session though. The latter may not describe the actions of the true Glocksters.
Those of us who shoot lead and cast our own boolits realize that one size does not fit all. In short alloy hardness, lube, chamber pressure, size over bore and powder burn rates are all variables that can lead to or prevent leading. Simply saying one form of rifling over another contributes to more or less leading is simplefication in the extreme.
Take Care
Bob
Something to keep in mind is that some cartridges and some lead bullets are more prone to lead any barrel than others are. A commercially hard cast 230 grain lead bullet should show minimal leading in 45 ACP. Commercial bullets tend to be very uniform both in size and hardness, and the pressures and velocities generated by 45 auto are low. A completely different senario is the 115 grain 9mm, the combination of higher pressures and normally higher velocities can cause an amazing amount of leading. I will note that I've handled 2 Glocks that went boom on their owners, both were 40 calibres and both shooters were loading 155 grain lead bullets to the high side of SAAMI maximum. Neither owner suffered any significant injury.
