.284 case Prep

[Brillo]

I have some new Lapua 6.5x284 brass that I've prepared for my .284 Win rifle. I've neck expanded with a 7mm mandrill and run the cases through a full length sizing die and chamfered the necks (I always F/L re-size). So, I now have a batch of what is effectively brand new 284 cases.

Will the rounds I now make shoot accurately or will the second firing be better? I ask this because I don't want to shoot them at my next comp if they are going to shoot all over the place but, conversely, if the new brass is supposed to shoot better I'll save them for the comp.

 

Thanks

[gbal]

Sometimes fire forming brass can shoot OK ( I know fire forming is more radical than what you are doing),but it is quite unlikely to be better than subsequent firings of the formed cases.It really is try and see,but there is some risk of reduced performance-best avoided for a precision competition,especially if you can't check maybe ten first....There is no evidence generally of second/third firings being inferior to new brass,if prepped accordingly.

Gbal

[nowler]

assuming whoever chambered your barrel kept it on min or close to min headspace, then they will be absolutely fine. load them and shoot them and don't stress over it, competition or not.

[That bald headed Geordie]

Stop worrying and shoot them. There are too many other variables (changing wind speeds/angles etc) to worry about at longer ranges.

As long as you prep your brass to the best of your ability then that is all you can reasonably do.

[5R-Twist]

Stop worrying and shoot them. There are too many other variables (changing wind speeds/angles etc) to worry about at longer ranges.

As long as you prep your brass to the best of your ability then that is all you can reasonably do.

+1

when I made my 7mm shehane cases I thought the same.

so I fire formed them and they shot as well at 600 as the fire formed ones do now.

[Ronin]

Assuming the 284 isnt an improved chamber - just shoot them.

 

If its improved (Shehane or otherwise), then you'll need to fireform the brass then load develop from there for best accuracy - only if improved chamber though.