Polygonal rifling??/

[Minesweeper3433]

Isn't poly rifling what the Desert Eagle pistol has for their 50 barrels? always thought it looked funny but my friend never cleaned his.

 

[mikecr]

From Magnum Research: http://www.magnumresearch.com/FAQ_deserteagle.asp
Why can I not see the rifling in my barrel?
The Desert Eagle features the innovative polygon rifling system. To the uniformed eye used to seeing the sharp edges of the land and grooves of typical rifling, the Desert Eagle pistols bore does look almost smooth and featureless. The polygonal rifling reduces gas leakage and bullet distortion and promotes higher velocity; longer bore life and easier cleaning.

 

[msinc]

Polygonal rifling??

"But it appears you just have a different way of learning.."

You are right about that, and if I live another 49 years I will still be doing it the same way...without you.

 

[Rtheurer]

I remember the first and Only Polygonal barrel purchased for a Service Rifle I was building. I also had a new Hawkeye bore scope and I stuck it in there all new wanting to see it. Well I was stunned since it was super shiney and I could see NO rifling at all...I though they screwed up till I ran a patch with some grey Graphite down the tube and then the lands started to show up a little in the scope.

That barrel started out bad, off the machine rest, like 2 1/2 MOA bad. We pulled it off and sent it in and had it Cryoed and put it back together. Its the only time I had witnessed an actuall huge group reduction after Cryo process. It now shoots just over 1/2MOA for 10 shots in the rest. It shoots very well when dirty also. Ill go as much as 200 rounds before cleaning.
I can see the rifling real good now that it has over 1500 rounds through it. But the first day when it was super clean and shiney.... Made me say what the..

Its a 20" Pacnor 1:7 Stainless Heavy AR15 countour.

RussT

 

[Minesweeper3433]

On the subject, I am very curious about this, who makes these?

 

[1shot]

I have tried to refrain from posting on this thread, simply because I don't have a "dog in the fight" so to speak. Having said that, everyone so far has lumped several different rifling profiles into one basket and called them by one common name. If you look through the offerings by the various bbl. manufactures you will see that they offer 5R, 5C, canted land etc. and they all have their subtle differences. The drawings that Mikecr posted are true renditions of Polygonal rifling. If you go to the Glock website you will see that they use both Polygonal as well as Octagonal broached bbls dependent on the caliber.
I can also tell you from experience that seeing the difference is as easy as doing a side-by -side comparison of several companies’ bbls. I own Broughton, Obermeyer, Bartlien and Krieger in 5 groove “canted land” configuration and they all have their subtle differences. However, they do have one thing in common…they all shoot!
I hope this helps,
Lloyd

 

[nam72]

Could poly rifling be the same as metford rifling? What's the difference?

 

[msinc]

Polygonal rifling??

I agree as above stated, different rifling types are being lumped into the title "polygonal." Prior to this Pac-Nor barrel the several different brand barrels I had ever seen and being referred to as having polygonal rifling all had several things in common...one of them being no sharp corners. The lands had no flat on the top and the grooves were not flat on the bottom. All corners were radiused. That is what I expected to receive based on the advertised title, because that is what is in the barrels of absolutely every other "polygonal" rifled gun I have ever seen or currently own. I got no problem with Pac-Nor, I have had fantastic results with the several barrels I bought from them and the guy that runs the show is first rate and very helpful too. My question now is why dont he just call it what it really is, 6R rifling?

 

[chino1969]

I have two Bartlein 5R barrels and a Pac-Nor polygonal barrel. One of the Bartleins is chambered in .243 A.I. and is a 1 in 8" twist. The Pac-Nor is chambered in .308 and is a 1 in 12" twist. They broke in easy, shoot very well and clean like any other.

 

[msinc]

This post was called back into my attention by a recent "like"...thanks for that. This was one of, if not, my very first posts here and I guess it wont be too bad if I do a follow up and add all the "likes" I didn't know I should have done back then.....
I wasn't sure back when I posted this thread of exactly who made that first barrel I had, but I have since determined that it was a McMillan barrel. The rifling in this barrel was rounded or very radiused and it was the second barrel I ever saw that was called "polygonal". The first being a Steyr GB pistol. The rifling in that gun appeared the same...rounded or radiused with no flats or corners. Several pistol barrels called polygonal later that all appeared the same, again radiused or rounded in both the lands and grooves, and I came to believe that this is what polygonal rifling was. At this point all the barrels "titled" this way had the same internal configuration.
I never did shoot the Pac-Nor 7mm barrel I got. I traded that barrel to my nephew for something he had that I needed, but I did barrel it to his action. I should have kept it, as it turned out to shoot lights out. Just to follow up on that, I did get another one in a #1 contour and built a "mountain rifle" that is a keeper.
Recently I lucked onto a 1-in-12 twist 308 Schneider barrel and built it on a 40X action I had. I used the same chambering reamer on this barrel as the original poly barrel I had. It shoots fantastic and I really like it...another keeper. I used to sell any accurate good shooting rifle I had if the money was right. Now I do not. I always ended up regretting it and had trouble replacing each one every time.
This was an old thread, and now fast forward to today, having borescoped just about every rifle barrel that is called polygonal I think I understand what mikecr was trying to say....there is no standard or one configuration that is "polygonal" like other rifling types. If you purchase 5 different manufacturers "polygonal" barrels you are going to see 5 different configurations of rifling. I will go on to say, many of which may not appear to be much different than conventional rifling.
I will also say that I might have been chasing a ghost all these years...that first barrel may have just been a lucky one that shot above average, irregardless of the rifling type. Since then I have owned every rifling types and brands made and none are a consistent "standout" and I cant find any advantage over conventional land and groove types, be it accuracy, fouling, ease of cleaning, etc.
Unless I have missed one or got the wrong barrel, NONE of the current manufactured barrels that are sold as polygonal have rounded lands and grooves. In fact, several of them are so "slight" for lack of a better term that they would be missed for conventional rifling and it must be there, but they make me wonder why they are called polygonal at all.

 

[Eddie Harren]

When polygon barrels and Schneider are mentioned, one needs to look no further than some of the names using them: USMC, Dan Dowling, Kenny Jarrett & ROBAR to name a few. David Tubb used only Schneider barrels for many years.

The USMC uses Schneider barrels but, they are not the 5P barrels.

 

[JRS]

The USMC uses Schneider barrels but, they are not the 5P barrels.

Perhaps this quote is an untrue statement: "Gary states that 95% of his barrel orders are for P5 rifling and that includes the barrels David Tubb uses and what the USMC installs in their sniper rifles. P5 rifling is not to be confused with the old polygon pistol barrels".

 

[Eddie Harren]

Perhaps this quote is an untrue statement: "Gary states that 95% of his barrel orders are for P5 rifling and that includes the barrels David Tubb uses and what the USMC installs in their sniper rifles. P5 rifling is not to be confused with the old polygon pistol barrels".

Before you accuse me of posting "untruths" maybe a call to Mr. Schneider is in order. Contact me via PM and I'll give you his phone #.

 

[cmillard]

i have spoken to Gary at length--hell of a great guy to talk to also! we brought up the USMC sniper rifle barrels and both conventional and polygon barrels were used. I think it depended on which version rifle it was on--I think the new m40-a6 went back to conventional rifling if I'm not mistaken.

 

[msinc]

I will say this about the Schneider barrel I recently obtained...first, I did not get it direct from Mr. Schneider, so it may be several years old for all I know. The outside of the barrel was very rough. It looked as if it had a fine thread cut fast down the entire barrel. It was contoured nicely, but honestly, it took me longer to smooth it up and get an acceptable finish on the outside of this barrel than it did to thread and chamber and headspace it!!! If a customer requested one I would have to add to the cost this polishing, but for me...i'd rub on one all day as long as I knew it would shoot like this. All that said, it sure does shoot good. Like I wrote previously, this ones a keeper!!!

 

[cmillard]

gary does that to his barrels because the marine corps wanted a barrel kind of rough like that in order to hold spray paint, or face paint to blend in with the environment.

 

[Eddie Harren]

I will say this about the Schneider barrel I recently obtained...first, I did not get it direct from Mr. Schneider, so it may be several years old for all I know. The outside of the barrel was very rough. It looked as if it had a fine thread cut fast down the entire barrel. It was contoured nicely, but honestly, it took me longer to smooth it up and get an acceptable finish on the outside of this barrel than it did to thread and chamber and headspace it!!! If a customer requested one I would have to add to the cost this polishing, but for me...i'd rub on one all day as long as I knew it would shoot like this. All that said, it sure does shoot good. Like I wrote previously, this ones a keeper!!!

My wife, Sara, set 2 IBS world records and was IBS Score Shooter of the Year with a Schneider barrel that I left the finish as delivered by Gary. I think she would have beat me with that barrel had I touched it after she started shooting it.

 

[msinc]

My wife, Sara, set 2 IBS world records and was IBS Score Shooter of the Year with a Schneider barrel that I left the finish as delivered by Gary. I think she would have beat me with that barrel had I touched it after she started shooting it.

I had to read this three times to get it...I first thought "beat" as in a higher score...you mean beat as in "over the head" for touching "her" barrel...yeah, I guess the barrel I got wasn't too terrible. I just let it spin against a single cut file for a while and then had at it with some wet-or-dry. Seemed like it was an hour but probably only 15 or 20 minutes.

 

[cowhtr]

This post was called back into my attention by a recent "like"...thanks for that. This was one of, if not, my very first posts here and I guess it wont be too bad if I do a follow up and add all the "likes" I didn't know I should have done back then.....
I wasn't sure back when I posted this thread of exactly who made that first barrel I had, but I have since determined that it was a McMillan barrel. The rifling in this barrel was rounded or very radiused and it was the second barrel I ever saw that was called "polygonal". The first being a Steyr GB pistol. The rifling in that gun appeared the same...rounded or radiused with no flats or corners. Several pistol barrels called polygonal later that all appeared the same, again radiused or rounded in both the lands and grooves, and I came to believe that this is what polygonal rifling was. At this point all the barrels "titled" this way had the same internal configuration.
I never did shoot the Pac-Nor 7mm barrel I got. I traded that barrel to my nephew for something he had that I needed, but I did barrel it to his action. I should have kept it, as it turned out to shoot lights out. Just to follow up on that, I did get another one in a #1 contour and built a "mountain rifle" that is a keeper.
Recently I lucked onto a 1-in-12 twist 308 Schneider barrel and built it on a 40X action I had. I used the same chambering reamer on this barrel as the original poly barrel I had. It shoots fantastic and I really like it...another keeper. I used to sell any accurate good shooting rifle I had if the money was right. Now I do not. I always ended up regretting it and had trouble replacing each one every time.
This was an old thread, and now fast forward to today, having borescoped just about every rifle barrel that is called polygonal I think I understand what mikecr was trying to say....there is no standard or one configuration that is "polygonal" like other rifling types. If you purchase 5 different manufacturers "polygonal" barrels you are going to see 5 different configurations of rifling. I will go on to say, many of which may not appear to be much different than conventional rifling.
I will also say that I might have been chasing a ghost all these years...that first barrel may have just been a lucky one that shot above average, irregardless of the rifling type. Since then I have owned every rifling types and brands made and none are a consistent "standout" and I cant find any advantage over conventional land and groove types, be it accuracy, fouling, ease of cleaning, etc.
Unless I have missed one or got the wrong barrel, NONE of the current manufactured barrels that are sold as polygonal have rounded lands and grooves. In fact, several of them are so "slight" for lack of a better term that they would be missed for conventional rifling and it must be there, but they make me wonder why they are called polygonal at all.

 

[284winner]

Glock pistols carry polygonal barrel rifling. I know this pertains to rifle barrels but just an fyi. Somewhat of a hexagon or octagon look.