5R rifling VS Polygonal rifling VS other types of rifling

[375rifleman]

I was just wondering if 5R rifling, polygonal rifling, or another type of rifling is better for inherent accuracy if everything else is the same?

375rifleman

 

[WeiserBucks]

In my opinion, no . Any of the various types of rifling available from the big names will be very accurate. Some folks swear by certain types of rifling, but I own them all and they're all very capable , none standing above the others in my opinion.

 

[Canhunter35]

There is a thread on here, fairly recent about barrels. Lots of good stuff. As far as I know there is no hard data saying that one type of rifling is better than another.

 

[MudRunner2005]

More accurate? Well... That's hard to determine. They can all be accurate. The 5R's benefits are in the design of the rifling. The design of 5R rifling has offset lands & grooves which causes less bullet deformation, which is supposed to lead to more accuracy from a less deformed bullet with equally applied pressure as it travels down the bore. The edges of the rifling are rounded and at lower angles than standard rifling, which will lead to less copper stripping from the jacket and building up in the rifling. So it allows more shots between cleanings, and less copper fouling, and copper buildup. It's design also makes cleanup very easy and quick.

I have rifles with all types of rifling, and many with 5R rifling, and there is a noticeable difference in shot-strings between cleanings, and also how quickly and easily it cleans up compared to standard rifling.

This is my experiences with it.

Polygonal rifling is mostly found in large-bore rifles and .45 ACP pistols. Occasionally you'll find it other calibers. All of my pistols with polygonal rifling are very accurate, but I'm honestly not sure if that has anything to do with the rifling.

 

[Gord0]

The only barrel I have currently that is 5r is my ar15. It's not highly accurate, but it does clean up faster than my other barrels. Probably the biggest falsehood I have heard about 5r was "my rifle has the 5r so I can get away with shooting the heavier bullets with less twist". Facebook groups are entertaining.

 

[375rifleman]

OK if everything ispretty much a wash accuracy wise I have have also read that polygonal rifling tends to lead to higher or more consistent velocities, generally is this true or just marketing hype?

375rifleman

 

[Gord0]

OK if everything ispretty much a wash accuracy wise I have have also read that polygonal rifling tends to lead to higher or more consistent velocities, generally is this true or just marketing hype?

375rifleman

Ballistics by the inch did a study in pistols on this. Can't remember what exactly their conclusion was, but I do remember that it was negligible.

 

[tim_w]

In major terms its all minor and honestly other than some very specific cases I think accuracy effects are a total wash. Cleaning and a slight peak pressure drop are what I have seen. But that is a very hard test to do properly without buying two identical 5g barrels. One with the R and one standard land shape. Then calibrate each one with P-test equip and see what you get. Issue otherwise is you have different land dimensions/ratios land to groove from different manf which all have and effect when looking at the effects of these changes.


I have tested Polygonals but the only ones I have had to test were PacNor and AR barrel from Noveske which is basically a pacnor. I as well as another person noticed borescoping they ran very large lands ratio to groove dimensions. I did not cast it or slug it to get exact but it had to be approaching 50%. These were 4 groove. I can not really say what effect the polygonal shape had as most all other barrels did not have such large lands. Really all I learned was at least in the 5.56 and .270 4 groove poly they used large lands compared to what I was use to seeing.

 

[BallisticsGuy]

Nobody could really define an accuracy difference to be because of the rifling. Too many variables to come out with anything but a correlative association at best. So the question is ripe for P-hacking but that's about it. That said, as has been covered, shots between cleaning are regularly affected in my experience. I use Columbia River Arms / Black Hole Weaponry barrels on all but two of my match rifles and they all shoot bugholes with just about anything I put in them. That's not due to the rifling I'd think. It's more likely due to the care with which each barrel was made and the handloading practices I use. My Hart and Shilen barreled guns are conventionally rifled and shoot just as well. I do notice that where my chamberings are identical between a poly and an enfield rifled barrel that the poly's turn in very slightly faster MV's. Slightly.

 

[Garycrow]

I've got three Bartlein 5R barrels, two sporter weights and one remington varmint contour. Every one of them shoots great and cleans easily. That being said, I'm not sure I see anything they really do better than conventional rifling and my absolute best shooting rifle has a conventionally rifled barrel. For my next build I'm going to go back to conventional rifling for no other reason than my gunsmith says he likes conventional better.

 

[durdy1]

My black hole weaponry 450 bushmaster and 308 shoot great. They really do clean super easy. Not sure on the speed as far as being faster.

 

[sable tireur]

Nearly a five year old thread and the OP has been gone a while:



375rifleman

Well-Known Member · From North East Missouri

Joined May 7, 2014

Last seen Aug 27, 2021

Best.

 

[PhilMW]

I was just wondering if 5R rifling, polygonal rifling, or another type of rifling is better for inherent accuracy if everything else is the same?

375rifleman

I am a fan of the polygonal rifling ~ less friction and a better gas seal. The absence of the sharp edges reduces bullet deformity, less carbon build-up, and easier cleaning. If it's a quality barrel you should get an increase in Velocity, Accuracy and barrel life.
Columbia River Arms offer great barrels w/ polygonal rifling and Faxon Arms has the 5R Rifling, which is Remington's version of Polygonal...
If you really are a stickler on long range accuracy send your barrel to "300 Below" for Cryogenic treatment - they do military SOCOM barrels. It helps reduce stress in the metal that can cause the barrel to flex as the barrel heats up.
If you compete or spend 10-15k on a once in a lifetime hunt ~ ANYTHING that can improve your barrel accuracy even 2-3% can mean success or failure at long range targets.

 

[BigDon]

I am a fan of the polygonal rifling ~ less friction and a better gas seal. The absence of the sharp edges reduces bullet deformity, less carbon build-up, and easier cleaning. If it's a quality barrel you should get an increase in Velocity, Accuracy and barrel life.
Columbia River Arms offer great barrels w/ polygonal rifling and Faxon Arms has the 5R Rifling, which is Remington's version of Polygonal...
If you really are a stickler on long range accuracy send your barrel to "300 Below" for Cryogenic treatment - they do military SOCOM barrels. It helps reduce stress in the metal that can cause the barrel to flex as the barrel heats up.
If you compete or spend 10-15k on a once in a lifetime hunt ~ ANYTHING that can improve your barrel accuracy even 2-3% can mean success or failure at long range targets.

I'm on board with most of your statements. I use Poly in my rifles that are, shall we say....higher rates of fire? Totally on board with 5R for sporting barrels. I've never been disappointed.

Between 5R and higher twist rates, things have changed, ladies and gentlemen!