9 MM lead & Polygonal Barrels

[HK9]

Any body have any experience with Polygonal Barrels & Lead bulletts. My H&K 2000 9 MM shoots any kind of jacketed bullet fine. But lead bullets don't seen to have the same acuracy. Any comments?

 

[DogBonz]

i have a theory

Polygonal Barrels work by "squishing" the bullet, not cutting into it. I think that the lead is too soft and dosent seal properly. Or, the the lead is too soft and is pushed through without enough friction to spin properly. I might be wrong but those are my theories.

I don't shoot lead mainly because I usually shoot indoors and the range doesn't allow lead indoors.

 

[P0832177]

Tradition thoughts are lead and polygonal rifling are precription for a Kboom! The reasoning is that the lead will build up, and then you will have the problem. Now, many people claim to shoot lead all the time and they are vigilant in their cleaning and watching for lead build up.

The prudent thing would be get an after market bbl from Jarvis and then shoot lead with confidence for your HK.

 

[strat81]

Can't speak for HK, but the Glock hexagonal barrel (or whatever they call it) is for jacketed bullets only. I'd rather pay the few extra cents than pay for a new barrel.

 

[DILLONHELP]

Polygon barrels are significantly tighter than conventionally rifled barrels. I suggest you read the book"the Glock in Competition", 2nd edition by Robin taylor. there is an entire chapter devoted to why Glocks blow up with lead bullets, written by someone that had to work up the information for use in court trials.
NO LEAD IN POLYGONAL BARRELS!

 

[highlander 5]

Shooting lead bullets in any standard twist barrel is going to be disappointing,
the 1 in 10 twist is too fast. 1 in 16 which is the same twist used for 38 Super handle lead much better. If you going to shoot lead get an after market barrel,
Bar Sto uses a 1 in 16 twist and holds match dimensions for chambers. I use one in my Beretta 92 and fired brass will fit back in the chamber with slight pressure.
Barrel is .3555 dia so .355 or .356 dia bullets may be used. They make barrel for most if not all the popular semmi autos price in the $200 range

 

[jaybrown]

plated bullets?

How do plated bullets fall into this discussion. They are much softer than full metal jackets but will they cause this "Build up" of lead or maybe the lead plating using the Polygon barrel?

 

[larryw]

I've had very good luck with some plated bullets in my 45ACP HK's polygonal barrel. "Some", as in West Coast Bullet (since gone, and now back and way overpriced). Not much luck with Berry's. Hardness of lead and thickness of plating had noticable effect on success.

Also had very good luck with Oregon Trail's super hard 200gr SWC lead bullets at bullseye speeds, but then I don't value my fingers and I shoot alone (where a kB will only injure me)...

Bear in mind this is with a 45, where velocities and pressures are much lower than a 9.

Suggested alternative: https://thebulletguy.com/categoryNavigationDocument.hg?categoryId=10

 

[SIRVEYR666]

How do plated bullets fall into this discussion?

I've shot thousands of plated bullets through my Glock 34 & 26 for years. They shoot just fine. I haven't noticed anything unusual.

I also know a gentleman that has shot thousands of lead bullets out of his Glock. He's had no problems. He is very dilligent about cleaning, though.

 

[P0832177]

I have shot Berry's 45cal 185RNHB bullets in my USP's with excellent accuracy.

 

[Stanley Greenman]

As it has been stated by manufactures of polygonal barrels, not for lead bullets.
They will function and really good, just super clean the tube after shooting. Be safe and super clean after every use.

 

[RyanM]

Polygon barrels are significantly tighter than conventionally rifled barrels. I suggest you read the book"the Glock in Competition", 2nd edition by Robin taylor. there is an entire chapter devoted to why Glocks blow up with lead bullets, written by someone that had to work up the information for use in court trials.

"Significantly tighter" how exactly? My Glock 23 has a groove-to-groove diameter of .400", and a land-to-land diameter of .393", which is the industry standard. And the lands are significantly narrower than the grooves, maybe 2/3rds the width, while most conventionally rifled barrels have equal groove and land widths.

No, they aren't tighter at all. The problem is that polygonal rifled barrels have significantly less engraving force. This, combined with the superior gas seal, give slightly boosted velocities with jacketed and plated bullets. But it apparently doesn't grip lead as well as the bullet would like.

 

[Shoney]

Aaaahh! UBAN MYTH - can't shoot leald in polygonal - rears its ugly head again.

This urban myth has been beaten to death over at glocktalk.com

Use hard cast lead or plated, shoot at moderate velocities, clean the chamber and barrel at regular intervals (every 100-250 shots), and DO NOT attempt to clean lead from a barrel by firing a jacketed bullet thru it.

Most if not every pistol manfacturer has legaleze to the effect that shooting reloaded ammo voids the warrantee.

 

[Master Blaster]

I have loaded and shot about 2000 PENN bullet hardcast lead bullets through my G26 Glock with no Ill effects, If you read the entire Glock manual cover to cover it does not even mention lead bullets. At least it doesnt in my G34 or G26 manuals. What it does say Is DO NOT SHOOT RELOADS. Thats because Glock has no way of knowing if your reloads are within saami spec for pressure. Its up to you to make safe reloads. Hardcast lead bullets work fine in a 9mm glock. I would not however shoot them in a .40 S&W glock the .40 is closer to the edge than the 9mm and many full power .40 lead loads without cleaning could drive up pressures enough to cause a Kboom IMHO.

Now if you own a Beretta 92 the manual does specifically say DO NOT SHOOT LEAD bullets. The rifling in a Beretta 92 is not polygonal its land and groove!!
And when I shot my Penn Bullet reloads in my 92FS compact, The rifling would have lead strips hanging from it after 25 rounds At that point the Bullets would be hitting the target sideways at 50 feet.
SCARRY it was. I dont know of any other handgun that does this and it has conventional rifling!!!! I think its because the Beretta has a very fast twist rate, too fast for lead.

I dont own the Beretta any more, sold it last year.

Now I also stopped shooting lead in my Glocks, because it does require some scrubbing to get the lead residue out of a Glock barrel. Instead I now shoot 125 grain Berry's plated Hollow points over 5 grains of Unique, a safe accurate load that runs 1050 +- 23 fps out of my G26 and a little faster out of my G34. The Berry's do leave a little copper residue.