Krieger Barrels offers a wide variety of twist rates as standard for our bolt action, M1A/M14, M1903, M1 Garand, AR-15 and AR-10 barrels. These twist rates are appropriate for commonly used bullet weights in their respective calibers. For those who want to go truly custom, we also offer non-standard twist rates in our bolt action barrels (Ask us about it). One of the great advantages in cut rifling is that in addition to very high uniformity in twist rate, we also have great flexibility in setting the twist rate.

• Bolt Action Twist Rates

Caliber (Click to build)	Bore Dia.	Groove Dia.	Groove Options	Twist
20	0.199	0.204		1-9, 1-10, 1-11, 1-12, 1-13, 1-14
5.45X39MM	0.214	0.222		1-7.1, 1-9
22 RF	0.217	0.222		1-16
5.56MM/22CF	0.218	0.224		1-6.5, 1-7, 1-7.7, 1-8, 1-9, 1-10, 1-12, 1-13, 1-14
6MM/243	0.2360, 0.2370	0.243	4	1-7, 1-7.5, 1-8, 1-8.5, 1-9, 1-10, 1-12, 1-13, 1-13.5, 1-14, 1-14.5, 1-15
6MM/243	0.2360, 0.2370	0.243	5R	1-7, 1-7.5, 1-8, 1-8.5, 1-9
6MM/243	0.2360, 0.2370	0.243	6	1-13, 1-14, 1-15
257	0.250	0.257		1-9, 1-10
6.5MM	0.256	0.264	4, 5R	1-7, 1-7.5, 1-8, 1-8.5, 1-9
270/277	0.270	0.277		1-8, 1-9, 1-10
7MM	0.277	0.284	4, 5R	1-7, 1-7.5, 1-8, 1-8.5, 1-8.75, 1-9, 1-9.5, 1-10
30 TIGHT	0.298	0.3065, 0.3070, 0.3075	4, 5R	1-12, 1-12.5, 1-13, 1-13.5, 1-14
308	0.300	0.308	4, 5R	1-8, 1-9, 1-10, 1-11, 1-11.25, 1-12, 1-13, 1-14, 1-15, 1-17, 1-18
338	0.330	0.338	5R, 6	1-9.35, 1-10
358	0.350	0.358		1-10, 1-12, 1-14, 1-16
375	0.366	0.375	5R, 6	1-8, 1-9, 1-10, 1-11, 1-12, 1-14, 1-18
38-55	0.366	0.375	5R, 6	1-12, 1-14, 1-18
408	0.401	0.408		1-10, 1-11, 1-12
416	0.408	0.416	5R, 6	1-12, 1-14
458 (STD LAND WIDTH)	0.450	0.458	5R, 6	1-14, 1-16
50 BMG (TIGHT) STAINLESS STEEL	0.4995	0.5095		1-15
50 BMG (TIGHT) CHROME MOLY	0.4995	0.5095		1-15
50 NE	0.500	0.510		1-20
500 JEFF	0.500	0.510		1-20
50 BMG STAINLESS	0.500	0.510		1-15
50 BMG CHROME MOLY	0.500	0.510		1-15







Additional Bolt Barrel Information:

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• M1A-M14 Twist Rates

Rifle Type (Click to Build)	Bore Dia.	Groove Dia.	Available Cartridges*	Std. Twist Rates
M1A-M14	0.300	0.308	.308	1-10, 1-11, 1-12


*Please specify .30-06 or .308 when ordering your barrel. The gas port dimensions differ between .30-06 and .308 and so we must know this even if we are not chambering your barrel.




Additional M1G, M1A, M1903 Information:

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• AR-15 Twist Rates

Contour (Click to Build)	Gas System	Caliber*	Std. Twist Rates
CARBINE	Carbine	.22 Cal	1-6.5, 1-7, 1-7.7, 1-9
MID WEIGHT 16.5 IN	Mid Length	.22 Cal	1-6.5, 1-7, 1-7.7, 1-9
MID WEIGHT 18 IN	Mid Length	.22 Cal	1-6.5, 1-7, 1-7.7, 1-9
H-BAR DCM	Rifle Length	.22 Cal	1-6.5, 1-7, 1-7.7, 1-9, 1-12
VARMATCH	Rifle Length	.22 Cal	1-6.5, 1-7, 1-7.7, 1-9, 1-12
VARMATCH - 28 IN	Extended	.22 Cal	1-6.5, 1-7, 1-7.7, 1-9, 1-12




Additional AR-15 Information:

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• AR-10 Twist Rates

Contour (Click to Build)	Caliber*	Std. Twist Rates
AR10/DPMS	.308	1-8, 1-9, 1-10, 1-11, 1-11.25, 1-12, 1-13, 1-14, 1-15, 1-17, 1-18
AR10/DPMS	6.5MM	1-7, 1-7.5, 1-8, 1-8.5, 1-9
M110	.308	1-10, 1-11, 1-12







Additional AR-10 Information:

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