Can I shoot lead bullets in my Glock?
This has been debated on rec.guns and GlockTalk about 10,000 times. There are basically 2 schools of thought:
School #1: Don't Do It
Glock barrels use special polygonal rifling not found in most handguns. This rifling is one of the main reasons Glocks are extremely accurate guns. However, the same rifling can cause a high degree of leading when not using jacketed bullets. In other words some lead from the bullet sticks to the inside of the barrel when it is fired. Too much leading can quickly lead to high pressures which can cause the barrel and/or gun to break or even explode. Most people who weigh in on this subject fall into this category including Glock Inc.
School #2: Don't Worry About It
If you clean your barrel well and do it every time you shoot there will be no significant leading. Many, many people use lead bullets almost exclusively in their Glocks and do not have any problems whatsoever.
Additional notes from Hoss:
Not all lead is created equally. You can shoot lead in your Glock (probably) but you should use a hard lead from a reputable manufacturer. The homemade lead bullets made from wheel weights and other recycled lead should be avoided! Just becuase one type of lead bullet and load shoot fine in one glock does not mean it will be safe in others. Each barrel is different and must be carefully checked when first using lead.
Additional notes from JT:
You *can* shoot lead in a polygonal barrel, as many Glocksters do. But you need to be aware of some potential dangers in using lead bullets, not to mention voiding your Glock warranty if you use non-factory ammo.
First, if you decide to use lead bullets, use hardcast bullets at medium velocities for best results. This will reduce potential leading of the bore. Theoretically, polygonal rifling allows the bullet to seal the gases better than traditional land and groove rifling, thereby increasing velocities but also increasing potential problems with bore-leading-induced pressure spikes. Lead particles from the bullets have no where to hide in polygonal rifling as in the lands and grooves of conventional rifling and with better bullet-to-bore sealing, serious pressure spikes can develop when the bore is fouled.
However, note that some dismiss the purported velocity increases with polygonal rifling. Mike Orrick (GlockTalk's "BrokenArrows") has pointed out that his chronographed results of identical loads in conventionally-rifled barrels versus same-length polygonal barrels yielded higher velocities in some of the conventionally-rifled barrels.
Secondly, absolutely get all the lead out after at least every 200 rounds to avoid lead buildup, pressure spikes and potential corresponding kBs! With the tighter seal of the bullet, pressures can increase significantly in polygonal barrels. There have even been reports of Ranier-type bullets shedding bits of copper jacket in polygonal barrels, causing the same pressure spikes that are caused by excessive leading. Just be sure to use hard-cast lead bullets or good-quality jacketed bullets and keep the velocities down to earth.
Thirdly, polygonal rifling doesn't get the same grip on the bullet as conventional rifling. This may affect accuracy with some loads, especially hot ones. Even with using copper-jacketed bullets, some LEAs have reportedly banned the use of polygonal barrels in duty guns because of the potential difficulty in forensically identifying the rifling patterns on a bullet shot from a polygonal barrel. IOW, it's sometimes impossible to identify which polygonal barrel a particular bullet was shot from. Who shot whom?
Another recommendation is to moly-coat your lead bullets and/or treat your barrel with one of the spaceage lubricants, such as TW25B spray from Kleen-Bore. This will definitely help the cleaning process and may even increase velocities slightly and help with accuracy.
Last, but not least, most experts recommend getting a conventionally-rifled barrel from replacement barrelmakers such as Jarvis or Bar-Sto if you shoot a lot of lead. These barrels generally offer more case support than stock Glock barrels as a bonus. Use your replacement barrel for practice and the stock barrel for carry.
I think that would be a good price. 
