Someone asked me over on the M14 forum about doing a batch order of Lothar-Walther polygonal rifling M14 barrels.

I know nothing about polygonal rifling. Can anyone tell me why I might want or need one? I'm super pleased with their button rifled barrels already, but I'm open to new (to me) things.

Thanks,

Tony.

My HK91 has polygonal rifling, I think HK used this in a lot of their rifles. Supposed to give added velocity as I recall.

I would venture a guess that the development of polygonal rifling had as much to do with the development of cold hammer forging of barrels as it does with any performance improvement. The mandrel would appear to be easier to make, and getting the barrel forged around it and getting complete "fill" would also be easier.

Benefits are better gas sealing and higher velocity but you aren't supposed to use un-jacketed lead rounds (not really an issue in a centerfire rifle)

They had polygonal rifling way back in the old days when all they had was lead. It is fine. HK has never said anything about not using lead. Glock started that because someone blew up a .40 caliber Glock while using lead topped reloads. It works just fine. This is an internet bs myth that spread like wild fire.

Polygonal rifling works well in accurate rifle barrels.

Polygonal rifling is reported to be easier on jacketed ammnition, and as such makes for a more acurate barrel. Given the number of truly supurb barrel makers that use cut rifling I question this. What I can tell you is the Swiss K31 is one of the most uniformly accurate mass produced rifle out there, and part of that may be it's rifling.

Another advantage to polygonl rifling is it lends itself well to hammer forging, which is something that the European manufacturers seem to favor. Either way, Walther makes an outstanding barrel.

Thank you for the feedback. I may just get a heavy M14 barrel just for giggles. What have I got to lose...

Tony.

Yeah, if any type of rifling had any extra benefit over other the types, the F-class shooters would be all over it. Extra velocity or greater accuracy, bring it on. Problem is, there is no such thing; rifling is rifling. The only thing that F-Class seems to agree on is a faster twist than before. For example, in 308 1:11 or 1:12 was the norm. Now is 1:10 or faster. Yes, we are using heavier bullets than before, but we went to faster twists even before the heavier bullets.

I think even benchrest folks have moved to faster twists, but I am very happy to be corrected on that.

And no, hammer forged barrels are not used in F-class. The precision is not there. Doesn't mean there are no great hammer forged barrels, it's just that the quality varies too much.

Lothar-Walther barrels are not found in F-Class rifles. But I have heard of great L-W barreled non-competition rifles so, go for it and lets us know the results.

Thanks Nikon. I am happy with their standard button rifled barrels. I only entertained this because people asked me to look into it.


My LW barrel shot 1/2 MOA before I pulled it out of the JAE chassis. It's now double-lugged, waiting bedding into a McMillan.

Tony.

quote:

Originally posted by benny6:
Thanks Nikon. I am happy with their standard button rifled barrels. I only entertained this because people asked me to look into it.


My LW barrel shot 1/2 MOA before I pulled it out of the JAE chassis. It's now double-lugged, waiting bedding into a McMillan.

Tony.

That is a very good reason to look into it and I wish you all the luck. With today's technology it's very possible for every manufacturer to make great barrels. I also think that button Vs cut rifling is probably equivalent in precision. I have had good success with a Broughton barrel, 10 years ago, I just migrated to Krieger and its cut barrels at that time and I have never had a bad one; they have all been great. At my age, it's tough to change a winning formula.

Of the other two methods of rifling, CHF and broach; their claim to fame is speed of manufacturing. CHF is much superior in result compared to the other. As an example, Ruger went in-house CHF maybe 20+ years ago and all of a sudden their rifle barrels, which had always been hit and miss, got a LOT better.

CHF is incredibly expensive in machinery, but it is FAST, so they make up for the cost by putting out barrels rapidly. When Krieger will take hours to rifle a barrel, a CHF machine will do it in minutes.

However, the thread here was about rifling and different configurations of it. As I said earlier, it's all hokum. 4 Vs 5, canted, 5R, polygonal, straight up, circle, what have you. There does not seem to be any difference in performance. As long as it's done properly, they all do the job equally well. If someone wants to believe that the polygonal rifling is superior, if they feel more confident with it, it's all good.

quote:

Originally posted by 357fuzz:
They had polygonal rifling way back in the old days when all they had was lead. It is fine. HK has never said anything about not using lead. Glock started that because someone blew up a .40 caliber Glock while using lead topped reloads. It works just fine. This is an internet bs myth that spread like wild fire.

I agree. I have a Glock 21 and have never shot anything BUT cast-lead reloads through it and it has not blown up. The only issue I have heard of that holds any merit is the possibility of having an issue when firing jackets bullets through a barrel that has heavy leading buildup that causes a tight bore and increased pressure when a jacketed bullet is then fired. But proper hardness lead bullets don't cause any leading in the first place.