6.5-06 RETUMBO/150 SMK VELOCITY LOAD DATA TEST

[mw22481]

Ok guys did some testing yesterday.
In case anyone is interested... 6.5-06 standard, Rem 700 28” benchmark Barrel.
RETUMBO/150 SMKS. First they did not stabilize in my 1:8 twist barrel. Targets had keyholes. Had no data on this powder/bullet combo so used Berger book 140 data and stepped down 2.0 grains. So from start load to never exceed it ranged from 2900fps- 3015fps being the highest I got with max 140 bullet load data. No pressure signs were observed in case head. Primers seemed fine. Just wanted to let anyone know who might be wanting to try this powder IT DOES HAVE SOME SPEED TO IT. I compared this powder to IMR7828sc, H4841SC, RL19 and H-1000 with the 150 smks as well.
The RETUMBO SMOKED them velocity wise.

 

[dworrel]

Interesting that it keyholed. I have shot Matrix 160's out of an 8.5 twist 6.5 SAUM without any stability issues. I am at 750 feet elevation (Texas).

I would be curious to see what N570 would do. I have a 28" Krieger 7.5 twist in 264 WM and am looking to do some testing soon, have gotten excellent velocities with Retumbo with 140's ~3250.

 

[mw22481]

Interesting that it keyholed. I have shot Matrix 160's out of an 8.5 twist 6.5 SAUM without any stability issues. I am at 750 feet elevation (Texas).

I would be curious to see what N570 would do. I have a 28" Krieger 7.5 twist in 264 WM and am looking to do some testing soon, have gotten excellent velocities with Retumbo with 140's ~3250.

Yeah that was disappointing as I was really hoping to take advantage of the new 150 smks high BC of .713. Unfortunately the 1:8 just wouldn’t stabilize. So next Barrel will be 6.5mm
1:7 twist and will be chambered in
6.5-06AI. And the will sling 150’s with retumbo. May try the Vitovouri powders as well

 

[Milo 2.5]

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

Figure what speed you need to stabilize the bullet at your elevation.

 

[mw22481]

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

Figure what speed you need to stabilize the bullet at your elevation.

I’m a sea level. Houston Tx
They were leaving the barrel at
2925-3015 FPS