Barnes 130gn TTSX TAC load in .308 Win vs .30-06

[JMRhino]

The published max Barnes TAC loads for 308 Win (51.2gns) and .30-06 (53gns) with the 130gn TTSX produce 3246 and 3165 FPS respectively. Both of the test barrels are listed as 24". I am curious as to why the '06 is almost 100 fps slower with 1.8gns more powder? Is the velocity difference due to chamber pressures?

I have direct experiences with the 308 Win. TAC load and have produced similar (sometimes faster) velocities. I am getting approximately 3248 fps out of my 20" barreled Bergara and 3126 fps out of a 16" Rem 700 LTR both in .308 Win.

 

[RL338]

TAC is a bit too fast for the 30-06. It would work with the 110gr TTSX better.
I toyed around with the 130gr TTSX in 2 30-06 rifles and never found the speed I wanted. Now move up to the 150gr TTSX and RL-17 , they together really shine in the 30-06.

 

[JMRhino]

Ah, very interesting. I assumed incorrectly that since 308 and 30-06 are so similar that the powder would directly correspond but I guess the powder burn needs to be slowed down a little since there’s more powder to burn…I am impressed by the 308’s performance with that load but that may not be the best domain for the ‘06. Thx.