Rifling Twist for 6.5x55

cdbeagle · February 18, 2013, 10:57 PM

I have a CZ 550 American in 6.5x55. The rate of twist is 1:9. All I have ever shot through it is PRVI 139 grain. The rifle shoots this ammo very accurately. I am planning on trying some other ammo that is higher velocity in 140 grain. I have read that the 1:9 twist in my rifle won't stabilize 140 grain bullets. It seems to do well with the PRVI though. What are your thoughts?

taylorce1 · February 18, 2013, 11:28 PM

It may not stabilize 140 solid copper or vld bullets but it will probably be fine for standard cup-n-core bullets. The only way to know for sure though is to shoot a variety of 140's to find out what you're rifle likes.

reynolds357 · February 18, 2013, 11:38 PM

My CZ550 6.5X55 shoots 140 bergers very accurately. If will stabilize a 140 Berger, I would venture it would stabilize all 140's.

cdbeagle · February 19, 2013, 12:02 AM

Thanks guys, I am fixing to start reloading(waiting for the equipment to arrive) and thinking about the Hornady SST 140 grain as the first bullet to try. Have you tried them and if so how was the accuracy?

emcon5 · February 19, 2013, 10:19 AM

I always fall back on Dan Lilja's FAQ for twist rates:

http://www.riflebarrels.com/faq_lilj...#twist%20rates

According to him, 1 in 9 in .264 will work for 140 gr bullets. My 6.5-06 is 1:9 and shoots 140s just fine.

tobnpr · February 19, 2013, 11:43 AM

Use the "bible", here:

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

Quote:

thinking about the Hornady SST 140 grain as the first bullet to try

Good BC for a hunting application, not as good as the A-Max, but still above .5.

I just noticed they introduced a 123 grain SST- perfect for our 6.5 Grendel!

reynolds357 · February 19, 2013, 01:42 PM

Shoot the Berger. My 550 for some reason only likes extreme boat tails. Example Berger and A-max.

GeauxTide · February 19, 2013, 02:48 PM

My 6.5-06, 9", shoots 140 Hornady and SGK wonderfully.

cdbeagle · February 19, 2013, 03:07 PM

Thanks for all the advice. I could not find the Berger Hunting VLD in 140 Grain anywhere so I ordered them in 130 grain.

reynolds357 · February 19, 2013, 07:14 PM

It shoots the 130 equally well. I used to shoot them in it, but I started buying the 140's in bulk because of my 6.5X284 1000 yard rifle. Touch the bullet to the lands.

cdbeagle · February 20, 2013, 03:08 AM

Thanks.

Olorin · February 21, 2013, 12:10 PM

"I have read that the 1:9 twist in my rifle won't stabilize 140 grain bullets."

The old Swedish Mausers M96 had a twist of 1-8.66. I shoot 160 grain Hornady rounds and they group at just over an inch.

February 18, 2013, 10:57 PM	#1
cdbeagle Senior Member Join Date: January 3, 2012 Location: Justin Texas Posts: 313	Rifling Twist for 6.5x55 I have a CZ 550 American in 6.5x55. The rate of twist is 1:9. All I have ever shot through it is PRVI 139 grain. The rifle shoots this ammo very accurately. I am planning on trying some other ammo that is higher velocity in 140 grain. I have read that the 1:9 twist in my rifle won't stabilize 140 grain bullets. It seems to do well with the PRVI though. What are your thoughts? __________________ Assistant Secretary - U.S. Dry Bean Council

February 18, 2013, 11:28 PM	#2
taylorce1 Senior Member Join Date: November 18, 2005 Location: On the Santa Fe Trail Posts: 8,242	It may not stabilize 140 solid copper or vld bullets but it will probably be fine for standard cup-n-core bullets. The only way to know for sure though is to shoot a variety of 140's to find out what you're rifle likes. __________________ NRA Life Member

February 19, 2013, 12:02 AM	#4
cdbeagle Senior Member Join Date: January 3, 2012 Location: Justin Texas Posts: 313	Thanks guys, I am fixing to start reloading(waiting for the equipment to arrive) and thinking about the Hornady SST 140 grain as the first bullet to try. Have you tried them and if so how was the accuracy? __________________ Assistant Secretary - U.S. Dry Bean Council

February 19, 2013, 03:07 PM	#9
cdbeagle Senior Member Join Date: January 3, 2012 Location: Justin Texas Posts: 313	Thanks for all the advice. I could not find the Berger Hunting VLD in 140 Grain anywhere so I ordered them in 130 grain. __________________ Assistant Secretary - U.S. Dry Bean Council

February 20, 2013, 03:08 AM	#11
cdbeagle Senior Member Join Date: January 3, 2012 Location: Justin Texas Posts: 313	Thanks. __________________ Assistant Secretary - U.S. Dry Bean Council

February 18, 2013, 11:38 PM	#3
reynolds357 Senior Member Join Date: December 10, 2012 Posts: 6,165	My CZ550 6.5X55 shoots 140 bergers very accurately. If will stabilize a 140 Berger, I would venture it would stabilize all 140's.

February 19, 2013, 10:19 AM	#5
emcon5 Senior Member Join Date: July 10, 1999 Location: High Desert NV Posts: 2,850	I always fall back on Dan Lilja's FAQ for twist rates: http://www.riflebarrels.com/faq_lilj...#twist%20rates According to him, 1 in 9 in .264 will work for 140 gr bullets. My 6.5-06 is 1:9 and shoots 140s just fine.

February 19, 2013, 01:42 PM	#7
reynolds357 Senior Member Join Date: December 10, 2012 Posts: 6,165	Shoot the Berger. My 550 for some reason only likes extreme boat tails. Example Berger and A-max.

February 19, 2013, 02:48 PM	#8
GeauxTide Senior Member Join Date: April 20, 2009 Location: Helena, AL Posts: 4,423	My 6.5-06, 9", shoots 140 Hornady and SGK wonderfully.

February 19, 2013, 07:14 PM	#10
reynolds357 Senior Member Join Date: December 10, 2012 Posts: 6,165	It shoots the 130 equally well. I used to shoot them in it, but I started buying the 140's in bulk because of my 6.5X284 1000 yard rifle. Touch the bullet to the lands.

February 21, 2013, 12:10 PM	#12
Olorin Member Join Date: February 8, 2013 Location: Arkansas Posts: 15	"I have read that the 1:9 twist in my rifle won't stabilize 140 grain bullets." The old Swedish Mausers M96 had a twist of 1-8.66. I shoot 160 grain Hornady rounds and they group at just over an inch.