OzFclass

Just an interesting point I have noticed and spoke to a friend about it last night.

With 6mm FO calibers it seems accuracy is fairly dependable around 3000-3050fps. Typical of a 6 dasher with 105's. Smack the X all day long in the short ranges.

In most 6.5mm calibers it seems that accuracy is good in the 2800-2900's. Typical of 6.5x47L and 130's and our 260 improved that we are using over here with 140's. Again both capable of great X counts and better performance at long range where it can get rougher.

The 7mm's really seem to shoot well and shoot more CONSISTENTLY WELL at around 2750-2820. So many stories of them having trouble with vertical when pushed harder and case life and barrel life is reduced. How many queens do we need to look back at where a 284 or shehane running at 2750-2820 had the edge over the other calibers across the whole shoot...

We know that we can always run bigger cases and push for faster accuracy nodes but again and again people make the choice to throttle back and shoot where its consistently accurate.

Im just interested if there is a possible link between bullet diameter and where reliable/dependable/repeatable accuracy is found velocity wise... Thoughts?

Brad, my dasher is humming along at 3025 so that sounds about right ........

I tried the 260 AI at 800m on sunday and it went really well. Its doing about 2960 and only needed 15.5min elev to get from 300m zero to 800m

That has to be flat enough and any more powder would just wear out the barrel faster. I was using 140vlds

cheers andrew

I have picked up much the same thing Brad. Most rifles seem to shoot quite happily at the velocities you have stated. I was chasing 3000fps with my 6.5x284 and just couldn't get the group. I wound it back to 2850 and bingo. I had reasonable groups with my current 308 pushing 155s at 3050, wind it back a bit and I started popping 0.2MOA.

Personally, I never sacrifice the group for velocity.

7mm and 6.5mm can run very well at 3000+ - it will be barrel/load dependent where they like to sit.

My current 7mm RSAUM LOVES 2930-3030. Others are driven well at 3100.
My 6.5*47 LOVED 3000 fps with the 123gr

And I know plenty more (especially 308).


It is barrel life and brass that is the driving constraint here not accuracy.....

Slow it down and you will get longer, accurate barrel life and this can account for a lot of people using a particular barrel well for a long time - there is less "flash in the pan" results.