Since I couldn't find any specific data, though some that was close I took the manufacturers word as to their burning rate chart. The case being a 6 Remington and the barrel a HART 1 in 8 finished at 28". The powder is VV 165 and the bullet a Hornady A-Max 105. Since I have used powders from IMR which "bracket" this offering I felt reasonably secure in my interpolations... I started 2.5 grains under where I thought I should finish, or about 7% below ASSUMED MAXIMUM. The first load shot with a velocity which exceeded the previous high for this weight bullet and cartridge for me., Apparent pressure signs were not worrisome.
V= 3128, SD 28 (note first round fouler was low of the string @ 3081) accuracy was good, well below MOA. So the next load was .5 gr more and the V= 3132 and an SD of 9, accuracy was not as good. another .5 gr and V= 3162 SD of 9 once again, then + .5 gr and the ASSUMED MAXIMUM V= 3184 SD 13 accuracy still lacking. I had also taken to load 4 rounds in my 6.5/284 as a double check and found lower pressure signs and higher velocity than normal for my rifle... That was interesting.

What I found amazing here was more powder didn't yield appreciably more velocity, or at least not the linear progression which often accompanies the work up. (1.5 grains + less than 60 ft/secs.) The only time I have witnessed this sort of situation was when the pressure was over the top, and velocity was not the product of the experiment. So next time I will work backwards from where I started this time.

Appreciate your comments as you see fit.

What do you think it could do in my 6mm Ackley with 95 grain bullets? Getting 3425 with Sierra 95 SMK's, and 47.5 grains IMR 4831 from a 26" barrel. 3600 fps with 49 grains powder (and Berger 95 grain), but too hot there.

quote:

What I found amazing here was more powder didn't yield appreciably more velocity,

I've found the same thing.....and it's not always the case.....but I'll bet you that there was an increase in the pressure!!!

This is just one of the many values of a chronograph..... and there are many more.

If you're gaining nothing then back off.....great discovery.

Vapodog, I most whole heartedly agree that pressure HAD TO BE ON THE INCREASE.



Tyler: It is too soon to tell what it might do in the Ackley version of the 6 Rem, though I bet we find out! It seems to have a rate close to R22 as V V claims. The velocities match my R22 work up, with slightly less apparent pressure. As Doc pointed out it is a very clean burning powder, and I think long accurate shot strings will be found, but at a lower velocity. I may try a lighter bullet to see how that responds to the powder against known established loads. But those are really for the 243 AI, so maybe I'll stick to the 105's and 107 I have on hand.

FWIW, my experience with VV N-165 in the .270WSM showed it to be almost identical to Reloder 22 in terms of velocity at identical load levels. The Vit powder was however more consistent both in variation and Sd, as well as accuracy on target. I think the VV powder is worth the premium price compared to the Re-22.

2ndtimer

I agree that the VV powders are worth the slight premium that is asked. Performance is superior on many levels in many cartridges in my experience.

quote:

Originally posted by 308Sako:
What I found amazing here was more powder didn't yield appreciably more velocity, or at least not the linear progression which often accompanies the work up. (1.5 grains + less than 60 ft/secs.) The only time I have witnessed this sort of situation was when the pressure was over the top, and velocity was not the product of the experiment. So next time I will work backwards from where I started this time.

Appreciate your comments as you see fit.

I agree with the statement above to an extent. When I'm pushing maximum the first thing that I look for (after feeling for the change in recoil, bolt lift and the case's visual differences) is a disproportionate change in velocity as compared to the previous data observed.

Usually the change that I see is a much smaller increase from previous load velocities.

quote:

Originally posted by Fjold:
[QUOTE]Originally posted by 308Sako:
. Usually the change that I see is a much smaller increase from previous load velocities

.

Frank, I absolutely agree with this comment regarding a change in the velocity per increment of powder. In this case I was working with a totally new powder to me, for which I did not have establish comparative data.