5r rifling accuracy, velocity, pressure vs. Regular rifling

[drykilned]

Newbie to the forum and to the 6.5 grendel here. Building one with 18" stainless hvy barrel and 5r rifling.
Anybody got any info on differences.

[Popeye212]

My goal was to build a 5r Melonite. Unfortunately I couldn't get one when I was ready to buy or just failed to research enough. The Melonite gives a little velocity increase according to one barrel vendor with claims of 10-20 fps or so. The 5r rifling is very accurate. My next barrel will be that even if I have to have it custom made. An example is the M&P Sport 15 the original came with this barrel. I am fortunate I bought before the Sport II came out with a different barrel. Accuracy in the Sport II is not equal to the original 5r so I have read your mileage may vary.

[drykilned]

Thanks, Popeye, i will try to keep posted how the build goes and test results, though they may be limited. Old age catching up. Parts are arriving daily.

[grayfox]

I prefer 5R rifling for a couple of reasons, 1) the lands are opposite a groove which to me does reduce bullet deformation and friction, 2) a 5R typically has a less square, more sloped edge design from the groove up to the land surface...

All that being said not long ago I was discussing a premium barrel for my 6.5 Creedmoor with a mfr and whether a 5R or 6-std land/groove design made a difference. His response was that for all the top shooters he supplied for, the land/grooves didn't make a diff, quality barrels shot well with either and lesser quality ones were, well, less good in general ... and this premium barrel I got from him, with 6-std grooving does indeed shoot lights out for me. So from one data point, maybe it's not as big a deal as the make and mfr of the barrel itself.
But I do still like the 5R's when I can get a good one from a good mfr...

[Popeye212]

I failed to to mention about the Melonite combined with the 5R the Melonite is supposed to give less friction along with rifling and reduced fouling and easier cleanup. My son who put a 5R on my grandsons 6.5 Creedmoore said had thinks he gets better velocity out of it. As I said your mileage may vary.