Obermeyer Approved 5-R™ Style Rifling Now Available!
(PLEASE completely read description below)
Thanks to approval by Boots Obermeyer, Krieger Barrels, Inc. is now offering the true Obermeyer 5-R™ rifling pattern as an option on limited calibers with our barrels.
At this time we are limiting the 5-R™ option to the calibers listed below, but may offer others in the future as greater demand arises.
PLEASE NOTE: We are not currently, and have no future plans to offer 5-R™ rifling in our finished 'Gas Gun' lines of M14, M1 Garand, AR-15, and AR-10 variants. Nor will we make a 5-R™ blank longer than 33" (32" finish length).
5-R™ rifling is ONLY available in standard bore/groove dimensions listed and standard twist rates (**) at this time. Please call if you have questions about availability of a certain caliber/twist combination.
There is a $30.00 up-charge to the base cost of the barrel for 5-R™ rifling.
Currently available bolt gun calibers with 5-R™ rifling:
6mm (.236" & .237" bore diameters, .243" groove)
** NO twist slower than 1-9 for 6mm 5-R™ barrels are available. Good authority has shown that short, light, 6mm bullets do not perform well in most 5-R™ barrels. We have no knowledge as to why, but do not want to risk an inaccurate Krieger Barrel being on the market.
6.5mm (.256" bore, .264" groove)
7mm (.277" bore, .284" groove)
.30T Palma (.298" bore & .3065", .3070" & .3075" groove diameters)
.308 cal (.300" bore, .308" groove)
.338 cal (.330" bore, .338" groove)
Description of 5-R™ rifling:
Visual aid to describe our 5-R™ style of rifling. Some dimensions have been changed to allow a better understanding of the rifling style. *Sides of groove have a 'ramped' transition to the land.
Not to scale
Visual aid to describe our traditional 4 groove rifling. Some dimensions have been changed to allow a better understanding of the rifling style. *Sides of groove are nearly parallel.
Not to scale
The Obermeyer 5-R™ style rifling is simply a different style of rifling that has a more 'ramped', or angled transition from the groove to the land and back down from the land to the next groove. Our conventional 4 groove rifling has nearly parallel sides to the groove. The internet is full of information describing perceived benefits to the 5-R™ rifling over conventional styles, but most of this is comparing "apples to oranges" as they are usually comparing one manufacturer's "non 5-R™" to a different manufacturer's "5-R™" barrels. We have honestly seen no significant differences in accuracy or performance between the two styles of rifling when comparing our barrels.
Thank you, Krieger Barrels