+- 6.5 Grendel Forum (https://65grendel.com)
+-- Forum: 6.5 GRENDEL DISCUSSION FORUMS (https://65grendel.com/forumdisplay.php?fid=3)
+--- Forum: 6.5 Grendel ARs and Other Semi-Autos (https://65grendel.com/forumdisplay.php?fid=8)
+--- Thread: Anyone producing a 3R rifled 6.5 Grendel barrel? (/showthread.php?tid=25037)
Anyone producing a 3R rifled 6.5 Grendel barrel? - Darryle - 10-20-2022
I know Harrison made a few, anyone else producing them?
18" or 20" 8 twist lightweight or heavy fluted, actually anything in the upper 20oz/Sub 2lb range would be awesome.
I don't know why I am such a nerd about 3r barrels, I know my Creedmoor and Wylde shoot great and clean easy.
Thanks Darryle
Anyone producing a 3R rifled 6.5 Grendel barrel? - 37L1 - 10-20-2022
Darryle Wrote:I know Harrison made a few, anyone else producing them?
18" or 20" 8 twist lightweight or heavy fluted, actually anything in the upper 20oz/Sub 2lb range would be awesome.
I don't know why I am such a nerd about 3r barrels, I know my Creedmoor and Wylde shoot great and clean easy.
Thanks Darryle
Might want to check Lilja.
Anyone producing a 3R rifled 6.5 Grendel barrel? - 65GbySeven - 10-20-2022
AR15 performance used to. You could reach out and see if they have any left.
Anyone producing a 3R rifled 6.5 Grendel barrel? - biodsl - 10-21-2022
Allegedly, a fluted 319 is in stock. Just over two pounds.
https://riflebarrels.com/shop/drop-in-barrels/ar/ar15/65-grendel/6-5-grendel-ar319-fluted/
Anyone producing a 3R rifled 6.5 Grendel barrel? - BluntForceTrauma - 10-22-2022
I think Lilja makes 3R barrels with wide lands so that the total area of the lands and, thus, the pressure characteristics of a given round were supposedly the same as a 6-groove barrel. I believe Harrison/AR15Performance used to make 3R barrels with narrow lands with the thinking that you could up the powder charge becauses friction resistance to bullet engraving was reduced. Theory remains a theory and is subject to debate. I'd be very wary of upping powder charges above book maxes. If you're a "3R Nerd" I'm probably telling you stuff you already know.
Anyway, that's getting off topic; no, don't know of anyone other than Lilja that regularly offers 3R.
Anyone producing a 3R rifled 6.5 Grendel barrel? - Fess - 10-22-2022
The relative width of the lands and grooves and their associated diameters is what the cross sectional area of a bore. The current thinking is that certain types of bullet work better with either more or fewer lands. Barrels with odd numbers of lands are thought to help center the bullets rather than allowing it to stay pinched slightly to one side.
A few months ago I got curious and calculated the land/groove ratios of some cartridges based on SAAMI specs. The SAAMI spec has both a suggested rifling configuration and a the cross sectional area of the bore. The Grendel and 6.5 Creedmoor land/groove ratio is about 33/67. Interestingly, the 260 Rem specs wider grooves and a slightly larger bore area with a (roughly) 30/70 ratio.
It turns out that the 270 Win and most other .277 cartridges (6.8 SPC and .277 SIG Fury included) are spec'd with a 25/75 ratio. A lot of .277 barrels made in the early 2000's, did not follow that recommendation, however, and had 33/67 or smaller. It was eventually discovered that many of the barrels that caused pressure issues with the 6.8 SPC were undersized so it is no wonder that cartridge had pressure issues. Harrison's "narrow land" barrels are just the SAAMI spec. I wonder if Winchester realized that many barrel makers were not following the 270 SAAMI spec when they decided to use 33/67 for their new 6.8 Western.
Anyone producing a 3R rifled 6.5 Grendel barrel? - grayfox - 10-23-2022
Fess, Any comparisons on differences in friction or heating with the different land/groove setups?
Friction loss is one energy-loss (and so subtracts from what will accelerate the bullet, all other things equal) and I don't think a lot is known or talked about, when it comes to internal ballistics.
Side note, I personally like the 5-land setup.
Anyone producing a 3R rifled 6.5 Grendel barrel? - StoneHendge - 10-24-2022
grayfox Wrote:Fess, Any comparisons on differences in friction or heating with the different land/groove setups?
Friction loss is one energy-loss (and so subtracts from what will accelerate the bullet, all other things equal) and I don't think a lot is known or talked about, when it comes to internal ballistics.
Side note, I personally like the 5-land setup.
I've never heard anyone call their a Lilja a fast barrel. I have heard quite a few call them slow over the years.