Why shouldn't you use lead bullets in polygonal rifled barrels?

dixidawg

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Glock and Kahr that I have both have polygonal rifled barrels. I have read that I should not shoot lead through them.

What are the technical reasons not to? Why is it the reason for this recommendation?

I know several people that have shot LOTS of lead out of their Glocks and say there has been no down side.
 
Polygonal rifling is not as deep and un-jacketed lead will more quickly foul it. I really wouldn't recommend ever shooting un-jacketed bullets for health reasons.
 
Cause people are too lazy to clean their barrels. The lead will eventually build up and the pressure will/ can increase to dangerous levels. It's the manufacture legally safeguarding themselves from laziness.
Perfectly fine to shoot lead if you clean it properly & regularly.
 
There is a very large thread on castboolits about shooting lead in polygonal rifling. It's not an issue at all. You just need to size and use a proper alloy and lube.
Like any other gun. If you try to use cheap off the shelf low budge lead ammo you could run into leading. A little work casting your own or buying from a company that can offer the size you need. You'll be fine. If you size right you won't need to clean lead out because there won't be any.

As far as not shoot lead for health reasons I'm not sure if that's a joke or not.
The most lead exposure you get is during actual shooting from the priming compound. It's lead based. It gets into the air and into your lungs. Dirty spent cases. Tumbling media. That dusty range covered in spent brass indoor ranges where the priming compound can linger. That's a health risk.
So is skiing and riding motorcycles but it's fun.
Shoot lead vs shooting jacketed won't increase your lead exposure. Don't lick your fingers or smoke while handling ammo and shooting and you will be fine.
Read the thread on castboolits. Very informative.

I cast my own bullets. Shoot a fair amount and handle plenty of lead. I get tested regularly for lead exposure and so does the rest of my family. No issues at all.







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Another option is to shoot coated lead, such as BBI, Bayou, Ibejiheads, etc. clean barrel every 500 or 1k rds to be safe. I prefer Ibejiheads.
I have about 3.5k 40 Ibejiheads through my g35, and probably 2-3k bayou through my g34 factory barrels. No issues.
 
According to Patrick Sweeney's book, The Gun Digest Book of the Glock, it's his opinion that .40 S&W kabooms are not from lead fouling the polygonal barrel. He suggests that there are two other factors involved, a) lead fouling in the "leade" which is the part of the barrel chamber just before the start of the rifling and b) bullet setback. His theory proposes that the lead fouling in the leade can prevent the cartridge from fully seating in the chamber causing an out of battery firing that may cause a kaboom, especially more so if there is some bullet setback. For these two reasons in addition to using a smaller bullet less than 180 grains, using a hard-cast lead bullet should not be a problem as long as the leade and barrel are cleaned more often (my opinion).

As I have mentioned in other threads, I do not use 180 grain bullets because there is not a lot of space left in the .40 S&W case when loaded with 180 grain bullets. There are numerous articles supporting this theory. As many know, bullet setback can and will increase pressures inside the case and the barrel chamber. In any event, Sweeney opines that hundreds of millions of .40 S&W rounds are fired per year through Glocks with an estimate of maybe 9 or 10 failures, so you have a better chance of winning the lottery than having a kaboom.

In addition, because the .40 is not fully encased within the Glock's chamber, a case that is re-worked several times may fail earlier in a Glock than one used in a chamber that fully supports the case because the Glock expended case has to be re-worked that much harder during the reloading process.
 
I shoot lead through my CZ82 9X18 Mak. Never had a problem. I do clean it after I use it though (usually). As far as accuracy goes, the lead seems to be as accurate as my jacketed reloads or commercial stuff.

When I was shooting 500+ rounds a week of 45acp through my Colt 1911 in the 90's, I used lead SWC's exclusively. Dead on accurate and never had issues with feeding or barrel leading
 
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isn't most .22 unjacketed?

Nylon coated. Which makes a big difference.

Airborne lead concentrations are substantially reduced (94% to 97%)by using ammunition with nylon-coated or copper-jacketed bullets. The only exposure will be from the base of the bullet and the primers. The primers are actually a minimal source of exposure.

Shooting unjacketed/coated outdoors there is sufficient air volume so that unless the wind is blowing back toward the firing line and proper cleaning/hygiene is observed it's ok. Indoors is another ballgame and really dangerous. Almost all cases of lead poisoning in shooters has to do with unjacketed ammunition used in old ranges without sufficient ventilation and backstops dependent on bullet shattering arresting methods.

Shooting a ton of copper jacketed bullets will eventually foul rifling the same as lead. But it takes a loooooooooooooooooooooong time to get that point.
 
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