Why no lead on polygonal barrels?

[Maksim 1,504]

Ok... so I keep hearing about not shooting lead boooolits down a polygonal barrel, ie, glocks, hk's, baby eagles.

 

I dont reload lead, only fmj/jhp/cmj, however want to know about this.

[tbtrout 141]

The sharper angles in the barrel shave off lead and cause a lot more leading and will lead to Kaboom

[lunker 274]

This guy doesn't like Glocks, but it's a good read.

 

http://www.thegunzone.com/glock/glock-kb-faq.html

[Parker 213]

Ok... so I keep hearing about not shooting lead boooolits down a polygonal barrel, ie, glocks, hk's, baby eagles.

 

I dont reload lead, only fmj/jhp/cmj, however want to know about this.

I have used lead bullets in my G21 and USP45 since I purchased them. I remember the Glock warning about reloads and lead bullets in its octagonal rifling. I paid some heed to them, and when opportunity presented itself I bought a match barrel from a firm going out of business for my G21 specifically suited for lead bullets because I fell into the hype. But prudent testing over the years, and sharing of information with my Glock compadres during range sessions showed me that the Glock and USP barrel shot lead loads well enough to warrant their use, provided I followed some simple rules. (The same rules that should always be followed whenever handloading.) You would have thought I was in a void of unknowledge until I joined a few internet forums over the last few years and read copious warnings of the ills of "lead bullets in polygonal rifling." Back when I got the Glock 21 in 1993, there wasn't a whole lot of information on the Internet then like there is today. Amazing that I still have all my digits after all these years and the G21 is still intact.

 

My take is if you exercise care and judgement in reloading, inspect cases after each firing, sort to discard suspect ones and separate and count the number of times your brass is reloaded, etc., etc., clean your gun's barrel and chamber every 200 rounds and use lead reloads that DO NOT exceed 850fps; you might be surprised at how well they shoot.

 

PS - I didn't know what a Glock "Kaboom" was until I looked it up this morning. There really is such a thing. I have been living in a vacuum.

 

Attached are some of my old targets using reloads with the Speer and Hornady 200 SWC bullet (which is pretty soft), using Bullseye, HS6 & Int. Clays powder. Groups at 30' & 50' were using a two-handed hold, and benchrested groups on a sandbag are noted for 25 yds. Certainly not X-ring accuracy for all of them, and the errors are evident on the shooter's part, but most loads exhibit accuracy potential; which was what I was trying to document back then for my reloads. Then, lead was so much cheaper than jacketed and was the route to go to to lessen expenditures. I will admit that jacketed bullets seem to shoot better in the Glock factory barrel, but some lead loads for practice were acceptable for me.

 

Note: The handloads used were safe in my pistols. Duplication is of course at your own risk.

 

My first lead reload - 09/1993 benchrested @ 25 yds. w/ 8.1grs. HS6, Horn. 200 gr. SWC

 

G21 w/ Speer 200 gr. SWC 4.5 grs. Int. Clays - rapid fire @ 30'

 

25 yds. G21 4.5grs Int. Clays/Speer 200 gr. SWC off sandbags

 

G21 @ 50' 4.5 grs. Int. Clays/200gr. Speer SWC

 

USP45 repid fire @ 50' w/ 200 gr. Speer SWC & 4.0grs. Bullseye

 

USP45 @ 50' w/ 200gr. Speer SWC/4.1grs. Bullseye

[lunker 274]

I didn't buy an aftermarket barrel for my Glock because of the standard rifling (although that is an added bonus). Glock chambers are nice and loose to facilitate reliable loading and extraction. In higher pressure rounds like 10mm, this causes the brass to get more worked than it does on a tightly chambered aftermarket barrel. The $110 I spent on a Lone Wolf barrel should hopefully be made up for by the extra life I will get out of brass that doesn't need as much resizing as it would with a stock barrel. The added accuracy is another bonus.

Of course if I were going to be carrying the gun or when using for home defense, the stock Glock barrel goes back in.

[Pizza Bob 1,488]

KB's in Glocks are more often caused by the unsupported chamber than any use of lead bullets. Ask Roger at Kings (in KofP, PA), maker of Roger's Better Bullets about how many rounds, loaded with cast bullets, he has fired through his Glocks.

 

Not sure how polygonal rifling is more prone to shave lead - the transitions around the "corners" are smoother than regular rifling with lands & grooves. Any firearm, regardless of rifling type, can KB from overpressure if there is extreme leading.

 

The trick is to use an alloy harder than pure lead. If you use the big bullet manufacturers (Hornady, Speer etc) swaged lead bullets, that is exactly what you are getting - pure lead. Even driven moderately fast, these will lead any barrel.

 

Most cast bullet makers use alloys of lead, antimony and tin in various proportions, depending upon the desired hardness. Some cast bullet manufacturers will actually give you a Brinell hardness of their bullets.

 

Don't fall into the trap of just getting the hardest bullet you can find - as they get harder, they get more brittle and they won't obdurate to the rifling (of any kind).

 

Examine your barrel and clean accordingly. IMHO, the no lead in polygonal rifling is more hype than fact - just know what you're feeding your glock and clean accordingly.

 

YMMV

 

Adios,

 

Pizza Bob

[Parker 213]

The trick is to use an alloy harder than pure lead. If you use the big bullet manufacturers (Hornady, Speer etc) swaged lead bullets, that is exactly what you are getting - pure lead. Even driven moderately fast, these will lead any barrel.

With soft lead swaged bullets, I found accuracy best at 650fps with Hornady or Speer. At that velocity, leading is not bad at all, almost nonexistent for a range session. With hardcast bullets, I can run velocities a little faster, but have found accuracy more evasive at times.