25 January 2018, 00:52
RIPhttp://faxonfirearms.com/blog/...-and-why-5r-rifling/
... there are advantages to 5R.
Only disadvantage I see is that the odd number of grooves makes it harder to slug the bore to check groove diameter. You will need advanced mathematics or special slug-measuring jig to check the groove diameter.
I ordered 5R from Krieger for my .264 Ripmoor wildcat.
I noticed nothing special about lack of fouling,
only that it has no remarkable fouling issues.
But it is the only Krieger I own.
My Ruger RPR in 6.5 Creedmoor has 5R and my Ruger American Predator in 6.5 Creedmoor has 6-groove/standard rifling of same twist, and I assume same bore and groove diameters.
Both those Ruger barrels have the same muzzle diameter too.
They both shoot the same size groups with Hornady factory, match-bulleted ammo, point-threes for three shots at 100 yards.
I have not shot them enough to notice any difference in the fouling.
Whatever turns your crank, but in a .375 H&H I think you would never see any detectable difference between 5R and standard 6-groove.
A 6-groove, 1:12" twist, stainless, .375 barrel from Winchester is the most accurate .375 barrel I have ever shot,
a point-one with a .375 Weatherby re-chambered .375 H&H.
But the bullet used is more important for accuracy than the barrel.
Shooter, ammo, barrel.
A 5R of same twist and contour might be just as accurate, might even foul less.
But how much does that matter?
Give it a try and let us know.
I wouldn't turn one down if someone wanted to give me one.
Rip ...
