Si-Snipe Posted July 26, 2014 Report Share Posted July 26, 2014 What are your thoughts regarding the polygonal rifling vs standard lands and grooves? Anyone have a barrel that they can share experience on the subject? Thanks Si Link to comment Share on other sites More sharing options...
DW58 Posted July 26, 2014 Report Share Posted July 26, 2014 Many H&K users seem satisfied with it. Link to comment Share on other sites More sharing options...
gunner Posted July 26, 2014 Report Share Posted July 26, 2014 Hi si , just thinking have any manufacturer done a sbs test ? To show any difference ? Not sure either if one type is harder to machine also . ATB - Tim Link to comment Share on other sites More sharing options...
dasherman Posted July 26, 2014 Report Share Posted July 26, 2014 Got a 6mm 8T No8 30" Pacnor poly in stock if you want one. Have fitted .308 ones, only apparent difference is they clean easier. Link to comment Share on other sites More sharing options...
Si-Snipe Posted July 26, 2014 Author Report Share Posted July 26, 2014 Got a 6mm 8T No8 30" Pacnor poly in stock if you want one. Have fitted .308 ones, only apparent difference is they clean easier. Hi Neil. Was just considering my next barrel for my 223AI. I still have the one I got from you on there now. It has 2300 rounds through it now. Cheers Si. Link to comment Share on other sites More sharing options...
c18rch Posted July 28, 2014 Report Share Posted July 28, 2014 Have polygonal fitted to three of my rifles now. Very happy with them. Little to no copper fouling, very easy to clean. Accuracy has been fantastic, and they are not fussy about loads. They seem to produce higher velocities than quoted in the reloading manuals, but I have never been able to do a direct comparison, ie my load in a conventional rifle with the same barrel length. The oldest one on my .30-06 AI has not deteriorated at all after 7 years and approx 3000 rounds. Which although isn't exactly an exhaustive study is better than I expected from a relatively hot load. It is almost equivalent to a 300 win mag being an AI. Link to comment Share on other sites More sharing options...
ChrisF Posted August 15, 2014 Report Share Posted August 15, 2014 I have always wanted to try a poly barrel , ever since I read a article on the old US Navys McMillan M89 suppressed sniper rifle , these rifles in 308 & 300WM , used a short barrel approx 17.5 inches long , and a large/long Suppressor , and they used a Poly barrel , and it seems they got good velocity from the short barrels , and long service life out of them as well . Later Chris Link to comment Share on other sites More sharing options...
ejg223 Posted August 15, 2014 Report Share Posted August 15, 2014 Gyr off this site uses a 308 with a (I think 1/10) 22" LW polygon barrel. He does very well with it at his long range goats using 168 a-max in Mallorca. edi Link to comment Share on other sites More sharing options...
meles meles Posted August 25, 2014 Report Share Posted August 25, 2014 Who makes polygonal rifles barrels? *Ponders one in 7.5x55 Swiss* Link to comment Share on other sites More sharing options...
1066 Posted August 25, 2014 Report Share Posted August 25, 2014 Not polygonal but I have a Shilen barrel with four groove ratchet rifling on my 6mmbr which shoots well and is easy to clean. Link to comment Share on other sites More sharing options...
DW58 Posted August 25, 2014 Report Share Posted August 25, 2014 Who makes polygonal rifles barrels? *Ponders one in 7.5x55 Swiss* Pac-Nor do Polygonal barrels - 7.5x55 Swiss is .308 so there you go Black and White set-dweller. Link to comment Share on other sites More sharing options...
c18rch Posted August 27, 2014 Report Share Posted August 27, 2014 Bartlein and Walther do them too. All mine are Pac-Nor. Just about to order my 4th for my .223. Link to comment Share on other sites More sharing options...
meles meles Posted September 10, 2014 Report Share Posted September 10, 2014 Hmmm, it seems like a heavy PH stainless Lothar Walther barrel in 7mm or thereabouts has a lot of merit... Link to comment Share on other sites More sharing options...
DW58 Posted September 10, 2014 Report Share Posted September 10, 2014 I'm quite keen on the idea - thinking of a .308 perhaps. Link to comment Share on other sites More sharing options...
ejg223 Posted September 11, 2014 Report Share Posted September 11, 2014 What I have always wanted to ask is, if the possible better surface finish of the bullet after leaving a polygon barrel has better BC values compared to a rifled barrel? Wind resistance should be lower, or? edi Link to comment Share on other sites More sharing options...
meles meles Posted September 12, 2014 Report Share Posted September 12, 2014 Quite probably: that is one (of several) reasons why many anti-armour rounds use a discarding sabot. After the sabot has been discarded the round flies on to the target in pristine condition, ie without any engraved rifling marks. I know on one projectile it was estimated by RARDE to add almost 200 yards to the meximum effective range against a particular type of test plate and increased accuracy too. I would image that a bullet from polygonal rifling might share some of those benefits. Although the bullet should distort a little to take up the polygonal section, the distortion will be less, cleaner and more regular than that associated with conventional rifling. It might be a sufficient improvement to enhance long range accuracy and maintain supersonic velocity for a little greater distance. Link to comment Share on other sites More sharing options...
c18rch Posted September 15, 2014 Report Share Posted September 15, 2014 What I have always wanted to ask is, if the possible better surface finish of the bullet after leaving a polygon barrel has better BC values compared to a rifled barrel? Wind resistance should be lower, or? edi That is one of the claimed benefits. It would be difficult to definitively prove. Interestingly I got some anecdotal evidence from Tiff's shoot this weekend. I was using my .308 with 155 A-Max’s which go subsonic at 900yds in my rifle were still grouping well a 1000yds. No evidence of them tumbling. I’ve seen them tumble at that range before but that is not necessarily related to mine being a polygonal, hence anecdotal. Link to comment Share on other sites More sharing options...
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