HOO-RAH!! SHOUT out to Krieger and Sierra!!

[carlsbad]

I know Sierra recommends 7.5 twist for the 150s but I'm going to try them in my 6.5 SAUM with an 8tw 5R barrel. --Jerry

 

[ShootDots]

@ShootDots

Anything to share yet?
CW

I know Sierra recommends 7.5 twist for the 150s but I'm going to try them in my 6.5 SAUM with an 8tw 5R barrel. --Jerry

I took the measurements of the 150SMKs and entered the dimensions into the "Berger Twist Rate Calculator". The calculator stated not only would they stabilize, it would maximize B.C. However, I tried them in an 8 twist / 5R barrel. They WOULD NOT stabilize! I was getting 4-5" groups at 300 yards! You will be going a little faster than my 6.5 x 284 BUT not that much faster. I hope they work for you>>>but I won't hold my breath. I have a 7.5 5R soon coming for those bullets..

 

[Ned Ludd]

SD - Hopefully, your 5R will turn the trick. If not, you might look into a Broughton 5C barrel. My understanding is that those lands are even easier on jackets than a 5R. However, that is only anecdotal information and I don't have any direct experience with one.

 

[1shot]

UPDATE!
I recently received my 7.5 twist, 5 groove 5 R barrel from Bartlien. I chambered it in a 6.5 GWI, which is an improved 6.5x55 Swede. This cartridge is comparable to a 6.5x284 in case capacity and offers Good Lapua brass at a lower cost than 6.5x284 and is very easy to keep in tune as well.
All testing was done at approx. 1,190 ft. ASL.
As of this date I have a total of 237 rounds down this barrel of the 150 SMK's with no blow ups. Additionally, I've tested both moly coated and bare bullets without issue.
Load development was done in velocities from 2,987 to 3,124 fps. I will say that the bullets seem to preform their best in the 2,980-2,990 range.
Other altitudes, powder choices, cleaning regimens etc. would/could might change your results, but these are mine.
I hope this helps,

Lloyd

 

[ShootDots]

UPDATE!
I recently received my 7.5 twist, 5 groove 5 R barrel from Bartlien. I chambered it in a 6.5 GWI, which is an improved 6.5x55 Swede. This cartridge is comparable to a 6.5x284 in case capacity and offers Good Lapua brass at a lower cost than 6.5x284 and is very easy to keep in tune as well.
All testing was done at approx. 1,190 ft. ASL.
As of this date I have a total of 237 rounds down this barrel of the 150 SMK's with no blow ups. Additionally, I've tested both moly coated and bare bullets without issue.
Load development was done in velocities from 2,987 to 3,124 fps. I will say that the bullets seem to preform their best in the 2,980-2,990 range.
Other altitudes, powder choices, cleaning regimens etc. would/could might change your results, but these are mine.
I hope this helps,

Lloyd

Thank You Lloyd for the update! I appreciate it!