Why are poly rifled barrels not more common?

[lw8]

Why are barrels like Schneider's P5 not more common in the precision rifle world? Tubb uses them and the USMC installs them on the M40s...but you see few if any in Benchrest competition and they are far less common than Kreiger, Bartlein, Broughton, and so on.

Are Schneider's barrels inferior or is the rifling process somehow less likely to produce an accurate barrel?

The cost is the same and they wait is shorter...

I have seen complaints from benchrest shooters that Poly rifled barrels are not lapped as smooth as conventional barrels and this causes them to copper up faster, but nothing to prove it?

So, why are Schneider barrels not more popular?

 

[Rust]

Whether true or not, many precision shooters do not consider them to be as accurate as a cut rifled barrel, in particular bench rest.

 

[lw8]

I read that as well. Is there any truth to it?

 

[AIAW]

I think it's just one of those situations where "one does the job well, why re-tool to change it up for the same outcome". I believe they are all hammer-forged too, in which the machinery is extremely expensive... on top of the process producing a lot of stress on the metal itself.

There are some of the best barrel makers in the country here on the forums, so I'd give their potential future input more gravity than mine!

 

[sandwarrior]

They are not more common because they are more difficult to make. They can be made by cutting, button or even hammer-forging. However, the latter IMO, would be pointless as it leaves stresses in the barrel. Anything gained by using 5R rifling, is then subsequently lost.

The top shooters in Benchrest are the ones who can really 'see' the minute differences in barrel accuracy. You will find button and cut rifling in those arena's. Very few hammer forged. As far as precision long range shooting, it's often up to the shooter to make up the differences in the top barrel makers. Dealing with the environment is the hard part. The environment is not a rifle thing, it's a shooter thing. One thing the 5R barreled rifles do is reduce friction on the bullet. Sort of like cheating a little more velocity out of it. Also, less physical movement of material in the bullet, while getting the same purchase on it, is why people feel they are more accurate.

One last thing. The 5R rifling style is becoming way more popular since it's introduction. You might not be seeing it, because you aren't at top level precision competition. Those competitors are going after Bartlein 5R barrels a lot.

 

[Frank Green]

Better double check your info. but unless I'm wrong the last time I looked the Marine M40's are conventional 6 groove. Not polygonal rifling. I'll call some Marine Snipers I know today and get verification on that.

Later, Frank
Bartlein Barrels

 

[seanh]

there are some benefits of a polygon barrel (better gas seal, less bullet deformation) but with barrels like Bartline, Krieger, Obermeyer accuracy isn't going to be one of them.

I've heard that fouling is reduced but again fouling isn't a significant issue with high end barrels. I've got a new Bartline that has 60 rounds or so through it...no blue coming out with Sweets 7.62...can't see a polygon barrel beating that.

As to Schneider specific barrels.- I've had one gun that had his barrel (M70 Custom Sharp Shooter)...most accurate rifle I've owned other than my benchrest gun and was extremely easy to clean. That was about 20 years ago. Don't know if they've changed quality or not. If the quality is just as good today, you can't go wrong with them. That said, this Bartline barrel I've got on my 700 very well may surpass that Schneider barrel...just haven't had time or good weather days to verify.

 

[Sauce787]

granted they're not bench rest rifles, but arent noveske ar's known for their accuracy? they use polygonal rifling in their barrels. I'm curious as to the real differences too

 

[lw8]

Better double check your info. but unless I'm wrong the last time I looked the Marine M40's are conventional 6 groove. Not polygonal rifling. I'll call some Marine Snipers I know today and get verification on that.

Later, Frank
Bartlein Barrels

That's interesting. My understanding was that they used a Schneider P5 rifled barrel and that in testing, it outlasted and outperformed its competition by a wide margin.

That's kind of my overall question...Schneider barrels seem to be used by a few serious shooters like David Tubb, but not many... It makes me wonder why they are or are not more popular....why are they not used in benchrest?

 

[M.rolen]

black hole weaponry is making me a polygonal rifled barrel blank that im going to test on a rem 700 that will be chambered in 223 i will post results of that when i get the build done. I am also doing one in 280AI that should be done within the month so i will let you guys know how they shoot and if i can tell any differences between them and traditional rifled barrels.

 

[lw8]

Also, I think we need to distinguish some terminology here...correct me if I am wrong.

Polygonal barrels- Glock uses this. The entire bore is shaped like a polygon.

Polygonal riflling- Schneider barrels P5 profile is like this. Conventional circular bore but the rifling lands are sloped like a polygon

5R- Canted land rifling, common proflie done by Obermeyer, Bartlein, Kreiger, and others.

All different...so is one superior to another? Why?

 

[Frank Green]

That's interesting. My understanding was that they used a Schneider P5 rifled barrel and that in testing, it outlasted and outperformed its competition by a wide margin.

That's kind of my overall question...Schneider barrels seem to be used by a few serious shooters like David Tubb, but not many... It makes me wonder why they are or are not more popular....why are they not used in benchrest?

Marine Corp. Still using standard conventional 6 groove rifling with a 1-12 twist. Not using Polygonal rifling unless it was just changed.

Tubb is buddy's with Schneider as I understand it. That's why he uses them. Why are they not more popular? Goes back to all the stuff with button vs. cut is one. The other is the bench guys are going with what wins and Bartlein and Krieger are pretty much dominating that sport and or Schneider doesn't push one type of shooting etc..over another and maybe only has the capacity to produce so many barrels etc...could be a bunch of reasons all put together. Who really knows.

Later, Frank
Bartlein Barrels

 

[jonbearman]

People generally are not comfortable with change. However why fix what isnt broke.

 

[TorF]

Polygonal barrels are more accurate than conventional barrels after you have put 10000 rounds through them. HK MG3 (MG42 in 7.62 NATO) polygonal barrels lasts much longer than conventional barrels.

 

[gyr2]

I have a polygon LW barrel on a 308, shoots great and cleans well.

 

[lw8]

I have a polygon LW barrel on a 308, shoots great and cleans well.

Not that it is totally germaine, but LaRue uses LW Poly barrels on all of his rifles and for better or worse, they do shoot well.

 

[lw8]

I wonder if the new LaRue barrels will be polygonal like the Lothar Walther barrels he used?

 

[fdkay]

I run a Schneider P5 1-11 twist on my .308, shoots very well and cleans up very easy. If the info can be believed, P5 barrels tend to shoot a bit faster than conventional barrels.
I also have a LW 1-10 with conventional rifling, shoots very well and cleans up very easy.
I used to have a factory Rem 5R hammer forged stainless barrel, it shot very well and cleaned up very easy. It wasn't as nice as my after market barrels, but it was the easiest to clean factory barrel I have ever had. It didn't seem to copper at all.

 

[Downzero]

Polygonal barrels are more accurate than conventional barrels after you have put 10000 rounds through them. HK MG3 (MG42 in 7.62 NATO) polygonal barrels lasts much longer than conventional barrels.

After you put 10,000 rounds through any rifled barrel, accuracy is a miracle.

 

[ChrisF]

P5

It might pay to look close at the P5 poly barrel ,as I think its not a real Polygonal rifling , more like a rounded version of the 5R type , when I was looking for a real , Polygonal barrel , LW was all I could find .
So a definiton of Polygonal rifling might be in order .


Later Chris

 

[Massoud]

Yes I got caught up in this years ago. Polygonal rifling is a bit of a misnomer. HK used true polygonal rifling in their PSG-1 (from what I understand) and would claim MOA to 20k rounds.

I wanted the same type and got a Schneider but found out it was not really polygonal, it was a sort of rounded land (it's explained more fully somewhere on the net). LW barrels are the same as we looked at using them on the Massoud, not true polygonal (they shot well still).

From what I was able to find out, the true polygonal barrels are hammer forged and I couldn't find a source for blanks. If you've looked down the barrel of an HK you can tell a definite difference, it's like looking through a kaleidoscope whereas the Schneider and LW looked to the eye like regular rifled barrels.
Justin

 

[Twitch2120]

doesnt Pac-Nor make a poly barrel?

 

[rpk762]

After you put 10,000 rounds through any rifled barrel, accuracy is a miracle.

Many high power shooters have uppers that have 10k on them. They are regulated to shooting 100 yards practice and even 100 yards reduced matches.

 

[Killswitch Engage]

Better double check your info. but unless I'm wrong the last time I looked the Marine M40's are conventional 6 groove. Not polygonal rifling. I'll call some Marine Snipers I know today and get verification on that.

Later, Frank
Bartlein Barrels

tis true.

 

[Frank Green]

It's also said that if you want hard core accuracy go with conventional/standard type rifling (what is called english style or whitworth style rifling). Basically where the land meets the groove at a 90 degree corner. I do believe this to be true also but when I get asked questions like this I ask the guy what is your definition of accuracy? What is your accuracy requirement?

I feel a 5R style rifled barrel will be as accurate or more accurate than a polygonal rifled barrel and in extreme cases a standard type rifling will/can be more accurate than the 5R.

Polygonal type rifling is seen more in pistol calibers than in rifle cailbers.

Later, Frank
Bartlein Barrels

 

[lw8]

http://www.zediker.com/books/rifleshooter/rs_web_promos/rs_barrels_spread.pdf


Interesting perspective.

Frank, you know more than anyone here...what do you think about his pushing a bullet down the barrel and viewing it as it goes, observing a better seal and more uniform contact with a rounded land rifling profile?

 

[delixe]

My only experience with polygonal rifling (other than a Glock) is with Blackhole Weaponry AR-15 barrels. Beginning of 2013 parts were scarce with the panic going on, and a few friends wanted to procure evil black rifles while they still could. BHW barrels were the only thing I could find in stock. 20" 1 in 8 twist BHW polygonal rifled barrels would not stabilize 77 gr. SMKs, but 16" conventionally rifled 1 in 8 barrels had no problem with the same SMKs.

 

[Frank Green]

http://www.zediker.com/books/rifleshooter/rs_web_promos/rs_barrels_spread.pdf


Interesting perspective.

Frank, you know more than anyone here...what do you think about his pushing a bullet down the barrel and viewing it as it goes, observing a better seal and more uniform contact with a rounded land rifling profile?

If you read the one part it says "it may produce more velocity." He doesn't say it does. As far as the seal thing goes? Same thing is said about 5R style rifling that the gentler angle on the sides of the lands etc.....and I hear from guys on a regular basis and claim the 5R barrels get more velocity than barrels with conventional rifling. Guess what I haven't seen it.

Pressures and velocity in my opinion have more to do with the total surface area of the bore then the style of grooves/rifling. Also the throat specs. of your chamber reamer can effect pressures and velocities as well.

When you pull the trigger and fire that round the bullet is the softest thing in the equation between the bolt, receiver and barrel and that bullet all of a sudden has 60k of pressure behind it the bullet is going to swell up in size some as it makes the jump from the case and into the rifling and as it gets into the rifling (regardless of style) the bullet is going to swage down to the bore dimensions etc....can some gas leak and escape by the bullet? I say yes. No way around it and regardless of rifling style.

Pope said the same thing about gain twist rifling. The gain twist because the twist is always getting faster towards the muzzle will to an extent seal off the bullet and help prevent gas cutting/escaping. In conjunction with the barrel having choked lapped into it. Not all barrels have choked lapped into them.

To get good data and trust what you hear....take 5 barrels made from the same steel and each lot of 5 barrels have rifling style A, B, C etc...in them. Also the barrels should be made as close as possible to the same bore and groove dimensions and twist etc....same type of steel as well. Chamber them all in with the same chamber reamer and run the same ammo thru them and conduct the test. That's the only way you will ever get hard concrete data but who has the time and how has the money to do all that. Most of us don't.

So when one guy tells me he had one (one barrel) that did this or did that and he believes that to be the holy bible you have to take it with a grain of salt.

Even from the same maker and using the same reamer etc...a difference of a 100fps from barrel to barrel is considered normal.

Later, Frank
Bartlein Barrels

 

[Frank Green]

My only experience with polygonal rifling (other than a Glock) is with Blackhole Weaponry AR-15 barrels. Beginning of 2013 parts were scarce with the panic going on, and a few friends wanted to procure evil black rifles while they still could. BHW barrels were the only thing I could find in stock. 20" 1 in 8 twist BHW polygonal rifled barrels would not stabilize 77 gr. SMKs, but 16" conventionally rifled 1 in 8 barrels had no problem with the same SMKs.

First are you sure they were true 1-8 twist barrels? Why do I say this? If the barrels were button rifled the button can slip during rifling if it hits a hard/soft spot in the steel. When this happens you can end up with a non uniform twist and or the twist will keep getting slower towards the muzzle. When this happens accuracy suffers and in some cases if the twist is on the ragged edge of stabilizing certain types of bullets again usually the accuracy is lost.

Also you get what you pay for. Barrels that are mass produced by manufacturers etc...usually don't have more than $30-$60 worth of labor, the high side I will say in the low $100 range (this includes the steel cost as well).

Later, Frank
Bartlein Barrels

 

[hessian]

Yes Pac Nor does offer polygonal rifled barrels.

 

[delixe]

First are you sure they were true 1-8 twist barrels? Why do I say this? If the barrels were button rifled the button can slip during rifling if it hits a hard/soft spot in the steel. When this happens you can end up with a non uniform twist and or the twist will keep getting slower towards the muzzle. When this happens accuracy suffers and in some cases if the twist is on the ragged edge of stabilizing certain types of bullets again usually the accuracy is lost.

Also you get what you pay for. Barrels that are mass produced by manufacturers etc...usually don't have more than $30-$60 worth of labor, the high side I will say in the low $100 range (this includes the steel cost as well).

Later, Frank
Bartlein Barrels

Good point.
I have not yet measured the barrel twist, although I may do that next time I get the cleaning kit out.
Nonetheless, I paid for a 1-8 twist. If they shipped me a barrel with a slower twist because their tooling f&cked up, well, that's an entire new discussion entirely.

 

[Aftermath]

BR does not reflect well on the rest of the shooting sports or military shooting.

A lot of BR guys have 30 or more barrels on hand and cherry pick the best. They will change often after as little as 500 rounds through a barrel.

The margin of error when shooting prone or standing off hand is greater than you will ever see when shooting some heavy unlimited BR rifle from a bench.

They spend more time on brass prep than anyone else and more money on reloading than anyone else. If they need to fireform often they will have a seperate rife with the exact same chamber cut buy the same guy and reamer just to fireform brass and save life on their "comp" barrel.

I would not worry about any perceived benefits that BR guys might think is real if your shooting prone or in any other off hand sport like Silhouette, NRA high power X-Course, PRS or F-Class. Most BR guys like fairly shallow button rifled barrels and a lot of non-BR shooters like deeper cut rifled barrels.

Accuracy has more to do with the gunsmith that is prepping the action and barreling the rifle + fantastic reloading precision+ ability to read wind and the shooting fundamentals.

BR is an art total to itself it would be like comparing F1 race car and NHRA Funny Car to all other forms of racing. Those two forms of racing are so specialized as to have almost ZERO carry over to all other forms of racing. BR is much the same.

Polygonal rifling gives the best combination of acceptable accuracy, easy load development with many bullet weights and powders, long barrel life and long intervals between cleaning before acceptable accuracy drops off!

It makes perfect sense that the marines would like these properties! If I was building a hunting rifle or a miltary sniper rifle I might like this as well. Likewise if I was building a hunting rifle, military sniper rifles, military machine gun or the like I would not only look at polygonal rifling but I would go CHF as well.

If I was building a BR gun I would likely consider a Hart, Lija or Shilen button rifled barrel.

I do not do BR. I started off in the 1980's doing Palma and NRA X-Course. Today I do high power Silhouette, Rim fire Silhouette and F-Class both unlimited and T/R. I prefer Brux but have used Douglas, Bargera, X-Caliper, Wilson, Krieger, LW and many other's. You either get an accurate barrel or you do not. I reload so I seldom get a barrel that will not shoot. Oh and I do Bullseye. I also hunt anything that is preferred edible or a varmint that farmers ask me to shoot.

So find a reputable barrel maker you like and a fantastic gunsmith! Learn the fundamentals of shooting as taught by the US Army or US Navy Marine Corp. and learn to reload and read the wind!

I highly recommend taking up some form of exercise either body weight exercise plus isometrics or weight lifting. Cardio is a plus if your joints can take it. Learn about and practice visualization as used by world class athletes!

I will say that my Dad was a drill sergeant and career military so I had a head start since he taught me the fundamentals and taught me that repetition is the mother of all learning! I learned to shoot at Ft. Benning and had fantastic mentors. Keen eye sight is always a plus but plenty of great shooters wear eye glasses. I wear eye glasses not that I am almost 49 if I am not shooting with glass! I can not emphasis how important it is to master the fundamentals and learn to read the wind if you want to shoot past 300m!!!!

If you do not reload stick to cartridges that have great support with match grade ammo from many sources!

Good Luck!

P.S. Do not fuss over who the PR guys favor they are a fickle bunch!

 

[Evintos]

I wonder if the rise of necro threads lately has to do with the similar threads suggestions at the bottom of the page.

 

[smoothy8500]

I wonder if the rise of necro threads lately has to do with the similar threads suggestions at the bottom of the page.

I'm sure that is the main reason. I wonder if the rationale is to generate activity and not necessarily "helping" us find more information.

 

[chevy_man]

I wonder if the rise of necro threads lately has to do with the similar threads suggestions at the bottom of the page.

Yup. I've clicked a few and started reading only to realize they were 10 years old and useless.

 

[Frank Green]

BR does not reflect well on the rest of the shooting sports or military shooting.

A lot of BR guys have 30 or more barrels on hand and cherry pick the best. They will change often after as little as 500 rounds through a barrel.


They spend more time on brass prep than anyone else and more money on reloading than anyone else. If they need to fireform often they will have a seperate rife with the exact same chamber cut buy the same guy and reamer just to fireform brass and save life on their "comp" barrel.

I agree the BR guys/sport isn’t like shooting F class or PRS or military sniper type shooting.

Some of the BR guys do buy a lot of barrels and will cherry pick. I tell the guys who change they’re barrels out at 500-700 rounds that they are psycho and should get real. They tend to pull them way to early in my opinion.

Also not necessarily true in terms of how many barrels some of those guys buy at least from us. Mark at our shop has been on the US world team. Contrary to what some might think…we only made him 4 barrels last year. He just shot a match two weeks ago and came in 4th and 9th place at 200 yards. He hasn’t pulled a trigger on a BR gun since last fall either. He also currently holds 2 or 3 world records in BR. NO and I repeat NO!!!!! He doesn’t get to cherry pick barrels by us. He puts in his order and we make him his sticks. He doesn‘t get 10 or 20 barrels etc…no need for it.

Later, Frank

 

[Frank Green]

Most BR guys like fairly shallow button rifled barrels and a lot of non-BR shooters like deeper cut rifled barrels.

Also not necessarily accurate. Standard SAAMI min spec. For most 6mm barrels is .237” bore x .243” grooves. Not even 5% of the BR barrels we make guys do they want the tighter .236” bore barrels. All of the top guys and again probably more like 99% of them are getting standard .237” x .243” bore size barrels.

I can’t think of a single time anyone from BR asked us for shallower grooves or bore barrels. Number of grooves? There we’ve made 3 groove, 4 groove, 5 groove, special 5 groove barrels with narrower lands (I will not make a 5R for a BR shooter), 6 groove and 8 groove barrels. No difference in accuracy with the number of grooves.

Years past 6 groove was the most common as that’s what the vast majority of button barrel makers made. When cut rifled barrels started to dominate BR shooting in the late 90‘s when we worked at Krieger….95% of the work was 4 groove. For the 30BR shooter I remember one year we only made like 16 barrels in 6 groove 30cal.

For us 4 groove was the most popular till about 7 to 10 years ago. Now it’s about a 50/50 ratio between 4 groove and 5 groove (not 5R!)

 

[spife7980]

Also not necessarily accurate. Standard SAAMI min spec. For most 6mm barrels is .237” bore x .243” grooves. Not even 5% of the BR barrels we make guys do they want the tighter .236” bore barrels. All of the top guys and again probably more like 99% of them are getting standard .237” x .243” bore size barrels.

I can’t think of a single time anyone from BR asked us for shallower grooves or bore barrels. Number of grooves? There we’ve made 3 groove, 4 groove, 5 groove, special 5 groove barrels with narrower lands (I will not make a 5R for a BR shooter), 6 groove and 8 groove barrels. No difference in accuracy with the number of grooves.

Years past 6 groove was the most common as that’s what the vast majority of button barrel makers made. When cut rifled barrels started to dominate BR shooting in the late 90‘s when we worked at Krieger….95% of the work was 4 groove. For the 30BR shooter I remember one year we only made like 16 barrels in 6 groove 30cal.

For us 4 groove was the most popular till about 7 to 10 years ago. Now it’s about a 50/50 ratio between 4 groove and 5 groove (not 5R!)

Why not 5r? Does square engraving introduce less drag or some variable vs 5r that alters precision? Or is it just that much tougher to make progressively narrower passes in rifling that can induce slight variations?

 

[KnowNothing256]

Why not 5r? Does square engraving introduce less drag or some variable vs 5r that alters precision? Or is it just that much tougher to make progressively narrower passes in rifling that can induce slight variations?

Calibers and Rifling | Bartlein Barrels

www.bartleinbarrels.com

 

[Frank Green]

Top pic is of a combination button right before it enters the barrel blank. You can see how it's bigger/pregnant looking.

Next picture is of the face of the blank. Notice how the steel is deformed from the button going in. Again button rifling displaces the material...it does not remove material. Also this adds stress to the blank. You cut and crown and or thread the muzzle and crown the barrel and the closer you get to the bore....you have a high probability of the bore opening up/going sour on you. Last place you want the bore to go sour is at the muzzle. This will have a negative impact on accuracy. Not uncommon to see the bores open up as much as a .0005".

 

[Frank Green]

Calibers and Rifling | Bartlein Barrels

www.bartleinbarrels.com

^^^^

The short jacket of the lighter and what I say is bullets of 80gr or less in 6mm. The bearing surface of the jacket is very short. The lands do the driving on the bullet and it's worse if the bullet is a boat tail style bullet as well. Just not a lot of meat there on the bullets bearing surface for the rifling to bite and drive the bullet.

Now take a 95gr or a 107gr, 110gr type 6mm bullet and those don't care. The 5R rifling is fine and what I run in my stuff.

When I had my 6PPC gun...it had a conventional 5 groove barrel. That gun shot in the .0xx's and low .1xx's if I did my part. I still have a 5x5 set of targets that I shot with it years ago down at the super shoot. For 25 rounds fired the groups averaged a .177". Smallest group was a .098".