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View Full Version : Glock vs. standard rifling


deanf
October 5, 1999, 01:16 AM
Can someone explain the difference between the rifling Glock uses (octagonal, hexagonal, or something like that) vs. standard lands and grooves (which I don't know anything about either)?

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George Stringer
October 5, 1999, 07:04 AM
Dean, most other guns have round bores with cut rifling. The Glock uses a polygonal bore like the H&K pistols. One of the major differences other than the shape is that the polygonal rifling tends to lead up much more quickly than standard barrels do. This can lead to increased chamber pressures and blow-ups. That's why lead bullets are not recommended in Glock pistols. George

Gale McMillan
October 5, 1999, 09:23 AM
The reason that a polygonal barrel will blow up when shooting lead is not due to fouling. It is that the soft lead wants to skid and if it does it locks up between two rifling flats and the pressure goes sky high. When I was making polygon rifle barrels the lead lap I used to lap the barrels some times would lock up and the only way you could get it out was to melt it out. If it were very hard lead it would help but why take the chance?

Gale McMillan
October 5, 1999, 09:23 AM
The reason that a polygonal barrel will blow up when shooting lead is not due to fouling. It is that the soft lead wants to skid and if it does it locks up between two rifling flats and the pressure goes sky high. When I was making polygon rifle barrels the lead lap I used to lap the barrels some times would lock up and the only way you could get it out was to melt it out. If it were very hard lead it would help but why take the chance?

deanf
October 5, 1999, 05:23 PM
So what, exactly, is polygonal in shape in the glock barrel? I've never studied one that closely.

If I was to look down the bore from the muzzle end, would I see an opening other than circular?

Andygold
October 5, 1999, 05:41 PM
I'm no expert, but in laymen's terms...When looking down the barrel, you see 6 raised mounds(for lack of a better word. Looking at a Model 19 barrel.) that spiral clockwise. There are no sharp edges as with standard rifling. At the breech end only, these little mounds taper off to a slightly lower profile. (kind of acting like a forcing cone. Standard rifling has raised areas that protrude into the barrel. These "lands" have square corners(90 degree, I believe). In between the lands are the "grooves" which also have square corners. The first thing that pops into my mind, as an example, would be the top of a picket fence(if the pickets were flattoped instead of pointed).
Hope this helps.

[This message has been edited by Andygold (edited October 05, 1999).]