Glock barrel question/observation

[zachomega]

Is it me or are the grooves in a 9mm Glock 17 barrel much more shallow than other barrels from other 9mm pistols?

Am I imagining this? Or are the grooves actually more shallow?

If so, I'm guessing the mindset is much like with marlin using shallow grooves for less bullet deformation and hopefully better accuracy.

-Zach

[TooBigToFit]

Is this your first gun with polygonal rifling? Just curious...

[frankski]

rifling.jpg

Glock barrels look like B.

[zachomega]

rifling.jpg

Glock barrels look like B.

Thanks for the visual. At least I recognized that it wasn't conventional rifling.

-Zach

[Delkal]

rifling.jpg

Glock barrels look like B.

Barrel B looks closer to standard rifling than my CZ-82 with polygonal rifling. Looking down the barrel it looks like a smooth bore.

Are Glocks somewhere in between?

[frankski]

Barrel B looks closer to standard rifling than my CZ-82 with polygonal rifling. Looking down the barrel it looks like a smooth bore.

Are Glocks somewhere in between?

The left illustration of B is a more accurate depiction of polygonal rifling than the illustration on the right. Polygonal rifling actually looks more like shallow waves.

[39flathead]

Barrel B looks closer to standard rifling than my CZ-82 with polygonal rifling. Looking down the barrel it looks like a smooth bore.

Are Glocks somewhere in between?

The CZ82 is more of a traditional polygonal rifling than the Glock which is a modified polygonal bore.

[Bang]

Google Why polygonal rifling? Plenty to read, such as interesting history on the inventor/early use of polygonal rifling:

https://en.wikipedia.org/wiki/Polygonal_rifling

[zachomega]

Is this your first gun with polygonal rifling? Just curious...

Yes it is apparently.

-Zach

[TooBigToFit]

Yes it is apparently.

-Zach

I hope that didn't come off the wrong way. I sometimes sound like a jerk when I don't mean to.

In any case, if you're curious, polygonal rifling is supposed to improve durability (since there's no sharp edges on the rifling to wear), velocity (since it forms a tighter seal around the bullet, and the grooves are smaller which means fewer gases escape), and some say accuracy. Some will also say that you shouldn't shoot non-jacketed lead in a polygonal rifled barrel, as some say that lead more easily builds up in polygonal rifled barrels, which causes constriction over time and a catastrophic failure (kaBoom). They are most often found in HK and Glock handguns.

ALL of that (except for being found in HKs and Glocks) is debated to no end on the Internet. People will argue that the velocity is not tangibly different, that the accuracy difference doesn't exist, and that you'll never shoot enough to wear out a lands-and-grooves rifled barrel. You'll also see people saying that you can shoot lead bullets out of polygonally rifled barrels.