338 LM Imp. Hydro form die worth it

[Bravo6niner]

Getting a barrel chambered up in 338 lapua mag Imp. 40*. Trying to decide if a Whidden hydroform die is worth it or am I better off fireforming to get some rounds down the barrel before starting LD? I plan on using flatline bullets exclusively with this barrel so with a hydroform die I could start the LD sooner granted the barrel will be speeding up during the process but surely I’ll still have some good data to progress with. Also I would assume the hydroform die isn’t going to form the brass perfect so I will still be slightly fireforming the first time I use the brass.

Any thoughts on this?

 

[Carolina Hill Billy]

I have the 280AI hydro die. As with all Whidden products, it works well. I've also wondered if forming cases was worth the effort. I can say that shooting the rifle is more fun with formed cases. My velocities are about 200 fps faster with the larger cases and a full load of powder. Even with hydroforming, the cases really aren't fully formed until you fire them 2-3 times. I have more free time at home than I have time to go to the range, so it made sense to form them at home and enjoy my limited time shooting.

 

[Milo 2.5]

Getting a barrel chambered up in 338 lapua mag Imp. 40*. Trying to decide if a Whidden hydroform die is worth it or am I better off fireforming to get some rounds down the barrel before starting LD? I plan on using flatline bullets exclusively with this barrel so with a hydroform die I could start the LD sooner granted the barrel will be speeding up during the process but surely I’ll still have some good data to progress with. Also I would assume the hydroform die isn’t going to form the brass perfect so I will still be slightly fireforming the first time I use the brass.

Any thoughts on this?

I'm sure barrel life is a concern here, but I'd bet the dynamics of your load will change with either FF or hydro forming. Given the fact 338 brass is thick and stout, I'd put a false shoulder on them, FF all you want to put in service upfront, that way you hammer the brass into form one and done.
FF loads can be extremely accurate. And remember, a lot of energy will be used up right in your chamber moving brass forward, so once brass is fired, do not assume you can automatically just up the charge.