Polygonal rifling

[BrokenArrow]

My BHPs and Rugers always shoot faster than my Glocks and USPs. I had a SW 4006 that shot faster than most G22s I matched it against too.

A polygonal barrel should hold what accuracy/velocity it does have longer than conventional rifling since it should wear less.

BTW, the local sheriffs blew up a G22 with factory ammo (Rem UMC 165 FMC). Ruptured barrel, peeled slide, cracked frame.



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[MarkCO]

Some of you guyts are really out there!

Polygonal rifling is more expensive than conventiaonls rifling to manufacture.

Polygonal rifling does lead badly and should not be used with lead. If you do, you are defying scientific test data! True, some folks do it, does not mean it is wise. Some people drink and drive even thought they know they should not.

Forensic analysis CAN differentiate bullets fired from different polygonally rifled barrels. True it is harder, but is is done routinely.

Polygonal rifling gives MORE accuracy and MORE velocity, in general. Glocks do not have some other things that lead to accuracy. Many aftermarket barrels have tighhter fits that give better accuracy. Solid recoil rods and a fitted barrel yields excellent accuracy out of polygonally rifled barrels. My G35 prints at just about an inch at 25 yards with a KKM and a factory barrel, both with solid recoil rods and fitting.

If anyone wants to pick my brain about polygonal barrels and their "issues", feel free to email me. I have testifyed on these issues and have examined 15 blown Glocks to date. My test data has been reviewed by personal from Glock and was found to be accurate from their viewpoint.

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Good Shooting, MarkCO

 

[Tom B]

MarkCo-Why is it that anyone who differs with your opinions is "really out there"? All I hear so far is your opinions just like ours! Lets see some DATA on what you say. Quotes from references,books,sources,etc... Not on Email or via secret handshake but here on the thread. I disagree with poly barrels are more expensive to make and that they are in general more accurate. I will do some research and see if I can produce Data to argue my point. I have never received any money from any gun maker so I am unbiased other than my personal experiences. Can you say the same? I own Glocks, H&Ks and other handguns that have poly barrels and they have their advantages. But the two items mentioned above are not them.

 

[MarkCO]

Tom B, differences of opinion are fine with me. You are more than free, in fact more than encouraged to have your own opinion. However, Mis-stated information, or inaccurate information is not okay.

While I have testified, I have not been hired by, or on behalf of a gun manufacturer nor have I ever received any compensation of any kind from a gun manufacturer.

Tell me again why, as a mechanical engineer who has extensive manufacturing design and process experience, I would not know the differences in cost of two different manufacturing processes?

Do you disagree with your plumber, auto mechanic, doctor often also?

I freely put up my occupation, my company web page, e-mail address, etc., so people can look at my qualifications and decide for themselves if I know what I am talking about or not. Can you say the same? Obviously not.

edited for typos.

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Good Shooting, MarkCO


[This message has been edited by MarkCO (edited May 27, 1999).]

 

[Tom B]

MarkCo-Since no data has of yet been forthcoming but you wish to talk about backgrounds as basis of who knows what,and you feel that being a mechanical engineer (which you seem to mention often in your comments) makes you right and you state that I for some reason will not share my background and am "inaccurate and mistated" I will be glad to respond. I am a maintenance manager with a carpet manufacturer and responsible for two plants. I have been in this job for 5 years. Before this I was employed with Michelin Tire corp for 20 years in 4 plants in 2 different states. I was in maintenance during all of this period as a team leader,supervisor, and manager. I have an electrical degree. My E mail address is Tom_Black@us.interfaceinc.com. My phone (706)812-6267. This doesn't automatically make me correct about my opinions any more so than your background makes you correct so get off your ego. My opinions are based on what I have read in books written by gunsmiths that are credible and published. Who knows,they may even be "mechanical engineers"! As I said earlier I will research tonight and bring exact data and what book,quote,etc... that I read to reinforce my opinions.

 

[Cheapo]

1. The gunsmith writing for the American Handgunner used a fixed barrel fixture to test about a dozen .45 ACP barrels from various makers and found that the differences between them were measured in 10ths and sometimes hundredths of an inch for group size averages. IIRC, every one grouped less than 2 inches at 50 yards. This included a box-stock, used, old USGI barrel.

2. In the same testing, barrels rifled with electro-discharge machining (EDM, like Magna-Ports) were a tiny bit less accurate. This difference was small but consistent enough to probably pass accepted measures of statistical reliablity. Sorry, I haven't run the numbers to get the confidence interval.

3. Sadly for this discussion, no polygon barrels were included.

4. I would surely believe accuracy/velocity data derived from similar barrel fixture tests of polygon barrels, using at least three each of rifled and polygon units to average out aberrations from individual samples.

5. I suspect that the "accuracy differences" among handguns with and without polygonal rifling reported so far are the product of fitting and operational variables from the gun design itself, rather than the barrel.

Let the data wars begin!

 

[MarkCO]

Tom B, reading is fine, but you can't beleive everything you read. Beleive whatever you want, it's your mind. You can even beleive the writings of those who want to take away our 2nd amendmenst rights, still does not make you correct.

I conduct testing on a regular basis, firearms and otherwise. But, I have no need to prove something to someone who has a problem with me or my posts.

True, I have an ego, but it was not manifested here, just don't like wrong information. I have posted well over 2000 posts on various boards and have mentioned I am a mechanical engineer maybe 5 times. That Tom is not often. I have had healthy debates with several other folks and while we may have left with differences of opinion, the facts are the facts, and we left with respect for each other. You are the only person who has posted in this manner in reply to my posts so I will just consider it abberant and move on.

This is my last reply to you or your posts on this thread. An open forum is not the place to get all bent out of shape and I wish to contribute to it no more.

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Good Shooting, MarkCO
http://homes.acmecity.com/rosie/smiley/58/

 

[walkin' man]

I smell smoke...

 

[Tom B]

From the Krause Publications book Gunsmithing: Pistols & Revolvers by Patrick Sweeney (available from Amazon.com). Chapter 16: Basic Pistolsmithing The Glock: Page 192: Under Barrels: Paragraph 3: I quote:"Although Glock barrels may not wear any better than any other top of the line match barrels,the rifling allows Glock to manufacture the barrels cheaply. The rifling on a Glock is also very easy to clean-with one big exception. Glock barrels hate lead." Under paragraph 6: I quote: "For those who want to stick with their Glock barrels, the question arises-is a Glock barrel accurate? Yes. With my Glock 22 in 40 S&W,I tested factory and reloaded ammunition using jacketed bullets. Accuracy was more than adequate for the pistols intended use." I used the chapter on Glocks as it was the only one in the book that addressed poly barrels. I will be glad to fax the entire chapter to anyone who wishes it. Make from this what you will and all opinions and experiences are welcomed as far as I am concerned.

 

[Cheapo]

Okay, we have a citation to Sweeney. It all flows well until he blathers about "Accuracy was more than adequate for the pistols intended use."

No definition of what the threshold of "adequate" is.

No report of how well the polygon barrel exceeded that undisclosed performance standard.

Absolutely no comparison of how well other types of barrels typically perform compared to that undisclosed performance standard.

My conclusion:
Sweeney is as full of s**t as the gunwriter dudes who crow about "excellent" "combat" accuracy with 3-inch groups at 15 yards!

The base data is hidden, so I consider Sweeney to be as reliable as the ignorant masses over on rec.guns.

TESTS!! TESTS!! I WANT TO SEE TESTS WITH STATISTICALLY VALID SAMPLE SIZES!!

I also want to see some accountant-type or manufacturing-type reports comparing production costs of, say, BHP barrels (or another linkless design) in broach-cut, button-rifled, and hammer-forged iterations. Maybe even for 5,000, 10,000, and 20,000 units, since there is a tooling cost for hammer-forged jobs that might make longer production runs cheaper but shorter production runs more expensive.

Puhleeze, satisfy our hunger for enlightenment.

Cheapo
Who asks all the impolite questions. Sometimes.

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Let us never forget that the only legitimate source of government power is the citizens. If WE cannot exercise a certain power, we cannot grant it to the state.

 

[Kodiac]

Guys, the talk about leading...

Lead is bad... Dont use lead. It is unhealthy, and does bad things to your guns.
Jacketed bullets are HAPPY bullets...
Naked Bullets are unhappy bullets...



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RAGE AGAINST THE MACHINE

 

[Rob Pincus]

I'll tell you guys what. I said back on May 8th that I was out of this thread, but I had to come back because I heard on another forum about how intonlerant and immature "we" at TFL were.

It embarrasses me that this discussion is still going on.

Everyone says that Lead is bad for Glock Barrels. Common sense and well documented test prove that Poly rifling creates the same or higher velocities for any given pistol barrel length. It is incredibly obvious that Poly barrels do not wear in anywhere near the same way that tradtional barrels do (1 million+ jacketed rounds and still within factory specs...).

Thread Closed for unecessary brutality to a dead horse.