Polygonal Rifling

[longhunter43071]

A shooting friend of mine wants to get a Pac Nor barrel in 6.5x284,8 or 8.5 twist 30".he asked me how the accuracy on the polygonal rifling compares.Has anyone shot one of these barrels in matches or hunting.

 

[rcw3]

I have a couple Pac Nor polygon rifled barrels, and frankly I would not buy them again,i.e. I would buy Pac Nor conventional rifled barrels, just not their polygon barrels). Speaking to Chris at Pac Nor, he indicated that they were unable to lead lap the bores of the polygon barrels because the lap gets stuck. As a result he said they lap them with a stiff brush. The net result is,1) I don't find the bores to be as smooth as the conventional rifled bores,don't clean up near as easy and foul more) and,2) I don't find the bores to be as uniform as a lead lapped bores.

My suggestion is go with a barrel that has 5C or 5R type rifling if you are looking for something that has the benefits of a polygon bore, but where the bore is uniform and smooth and can be lead lapped.

The same goes for something like a Schneider polygon barrel. I tried a few of them, and by and large, I find the bores to be not as smooth as conventional rifled bores, and second, I don't feel they are as uniform.

Just my thoughts on the subject.

Robert Whitley

 

[Will]

On the other hand ... I find my Schneider P5 barrel to be easier to clean, less harsh on bullets, therefore less copper,did I mention easier to clean) and smooth. In fact as soon as I shoot out a Shilen match barrel I'm going to order another Schneider from GA Precision. If they are good enough for David Tubbs,all his T2K rifles) then maybe they will help me. Since I can't afford a T2K I can at least use the barrel. love mine. BTW, mine is a 308 WIN.

 

[rcw3]

On the other hand ... I find my Schneider P5 barrel to be easier to clean, less harsh on bullets, therefore less copper,did I mention easier to clean) and smooth. In fact as soon as I shoot out a Shilen match barrel I'm going to order another Schneider from GA Precision. If they are good enough for David Tubbs,all his T2K rifles) then maybe they will help me. Since I can't afford a T2K I can at least use the barrel. love mine. BTW, mine is a 308 WIN.

Keep in mind Tubb also sells his Final Finish,fire lapping) bore polishing process for these barrels - that should say something. I have four Schneider P5 barrels, and I have bore scoped them many times, and I can say for certain the bores of those P5 barrels are no way as smooth,most have visible machine marks in the bore) as premium lead lapped barrrels,i.e. Bartlein, Krieger, Hart, Broughton, Lilja, Kostyshyn, etc.).

If the issue is accuracy, look at what barrels are winning benchrest matches. I don't think I have ever seen the polygon barrels we're talking about in the winner's equipment listings, but I have regularly seen barrels by Bartlein, Krieger, Hart, Broughton, Lilja, Kostyshyn at the top.

Robert Whitley

 

[RickB]

In addition to Robert's comments the couple of Pac-Nor "polygonal" barrels, I am aware of have had large bores and were not easy to develop loads for and did not shoot as well as their conventionally rifled barrels. The exact shape of a "polygonal" barrel seems to vary sufficiently from one manufacturer to another that it is difficult to actually compare them directly. They simply are not all the same.

My personal experience with Pac-Nor's 3 groove,conventional) 6.5 mm and 7mm barrels has been good. I would, however, be inclined to go with the 5C/5R type rifling.,I have one from another manufacturer being chambered at the moment.)

 

[Will]

rcw3, EXCUSE ME !! Didn't realize that it was Benchrest ONLY. Who cares about Camp Perry or Raton? I forgot that shooting from a machine rest with a big butted rifle was what mattered. I defer to your benchrested wisdom.

 

[rcw3]

Will

FYI, I am not a benchrest shooter but focus my attention on Long Range and Across the Course. We're all in the search for the best accuracy and my point in bringing up benchrest shooters' choices of barrels is that, as a group, they are the most demanding for accuracy,i.e. a .25" MOA angle group at 100 yards does not cut it at all with those guys).

Borescope your P5 barrel someday next to a Krieger, Bartlein, Hart, etc., you'll see for yourself what I am talking about.

Robert Whitley

 

[Will]

Benchrest is a fine bunch of guys IF you can afford to change out barrels every 1200 to 2000 rds. Bughole accuracy is wonderful where needed but in my past life ...I'd settle for one shot where it counted and move on to other matters.

yes, Tubbs does sell that Final Finish product and I guess it works but I've never used it. As long as when I finish cleaning my barrel and a soft cotton patch goes thru smoothly,No drag or sticky spots & very light grey look) ... I'm G2G. Im sure the top names you mentioned are very fine barrels. Most don't agree with me about using moly, I use it). I think I have read on some site that some barrel makers void their warranty if they find you have used abrasive material in their barrels.

The originator of this thread was asking about accuracy and longevity,or something close to that)... so far this Schneider barrel has 4,700+ rounds through it and still gives me <1" @ 100. Sometimes 1/2MOA when I do my part. That makes my day. When I can take a new load and shoot 600 yd steel and cover the 5 shot group with a dollar bill ... yes I will keep shooting w/ the Schneider ! Your results may vary

 

[Eddie Harren]

"Not many polygonal barrels winning benchrest matches" How many polygonal barrels were being used? Let someone win a major BR match with a polygonal barrel and there will be a run on them!
Ten years ago noy many gaintwist barrels were winning benchrest matches either.
Mostly because none were being used. Nowdays there are quite afew gaintwist barrels are being used and some are winning.

 

[HPMike800]

I have a friend who shoots Schniders, their accurate enough. He wins most of the mid range matchs around here. They don't seem to last very long though. I'm a 5R fan