polygonal rifling?

[eastwood44mag]

Three questions.

Who does it? What's the difference? Why do they do it?

Thanks, all.

 

[knoxx45]

It is...

Rifling that does not use the traditional lands and grooves. Instead, if you look down the barrel, you will see that the barrel is not round inside. It looks like someone dragged a hexagon through it.

The reason for this is that it provides a better gas seal between the bullet and barrel, with less trauma to the bullet, resulting in higher velocity and better accuracy. Also, they are easier to clean and last longer.

HK and Glock use this kind of rifling, as do some others.

 

[eastwood44mag]

Wow. That was fast, and it made sense. Thanks much.

I guess that so few do it because it's more expensive. Correct me if I'm wrong.

 

[knoxx45]

If you want a good visual

atlantisarms.com/History/Barrel%20History.htm

 

[browningguy]

I would agree with the above as it relates to production barrels. However I think most of the long range accuracy nuts still use cut rifled barrels, not absolutely sure mind you, just seems that way to me. I will say that my Witness Match with polygonal rifleing is the most accurate production pistol I own by a good bit.

 

[Lucky 7]

my pre-2005 BE has polygonal rifling and is my most accurate production gun. Great, great design (the polygonal rifling) and more companies should use it IMHO.

-L7

 

[possum]

I know glock and one that hasn't been named yet is kahr. the only thing about that type of rifling is that glock and kahr especially recommend that you don't use lead rds in them. I heard from a few sources and then actually called kahr myself and they confirmed that they recomend against using lead rds. but a t the same time, a friend of the families has been using lead and only lead in his glock ever since he bought it a few years back!

 

[mrtgbnkr]

I accidentally bought several boxes of lead for my HK...they were on clearance and WAY cheaper than I usually saw .40 going for. Once I got home and realized they were LRN I found out why.

Not wanting to damage my pistol, I called HK and spoke to one of their gunsmiths. He said that they recommend against lead because it can build up in the barrel, but that it would take very high round counts before it would build up enough to do any damage. The recommendation was to go ahead and shoot it, but to run a brush thru the barrel every 50-100 rounds to get rid of any build up. The biggest problem he mentioned was that the build up might affect accuracy (it did, but I'm no bullseye shooter either).