Question on making 260 brass and it's accuracy

[mugsie]

Hope this belongs here but here goes (the mods will move it if necessary).

I shoot 6.5mm (260) quite a bit at ranges anywhere from 100 - 1000 yards. I noticed that when I use .243 brass necked up to 6.5mm, the accuracy seems to improve. All other factors are equal, same powder, bullet either (120 or 140g), same primer etc. when I use the necked up 243 brass, my grouping is always more consistent and tighter.

What do you think? Could it be the greater neck tension? If so, how do I go about replicating it on my 260 brass?

Thanks for the help.....

 

[DocB]

mugsie,

Lower neck tension, higher neck tension; the real question is what else do you do to prep the brass? What brand of brass?

Thanks,
DocB

 

[leadbullet]

I do neck up win 243 brass to 260 also and have better accuracy and less pressure than same load in lapua brass. It gets annealed every other shot and is on the 9th loading, primer pocket is tight and still hammers at 1250yds. couldn't be happier.
cheers.

 

[mugsie]

Leadbullet, that is exactly what I found.. Necking up .243 brass seems to be far superior than any commercial brass I've bought. Guess I'll just continue this practice, and yes, I too anneal but usually after third or fourth firing. Guess it is the neck tension.

 

[Aushunter]

I do neck up win 243 brass to 260 also and have better accuracy and less pressure than same load in lapua brass. It gets annealed every other shot and is on the 9th loading, primer pocket is tight and still hammers at 1250yds. couldn't be happier.
cheers.

Hi leadbullet, so are you suggesting that with less case neck thickness due to the neck being stretched with a mandrel(??) the projectiles exits the case mouth easier??

If so wouldn't neck turning have the same effect?