.338Lapua Imp information for new project

[spindrift]

Hi guys any suggestions for barrel length and twist rate for a .338 lapua Imp also any load data would be great/ balistic tables etc. Projectile will be 250 grn Scenar Lapua.

cheers

[wadcutter]

Spindrift,
I have a 1 : 10 twist in my .338 Edge. Barrel length is 30". Can get 2950 fps with hot loads with the 300 gn SMK and run fireforming loads at 2800fps. Over 3000 fps is easy with 250 gn Hornady BTHP match. My chamber has a long throat so would have a similar powder capacity to your .338 Lapua imp.

Just use normal load data for a standard .338 Lapua and if safe, slowly increase the powder charge in your improved chamber.

Be very carefull as I hear that the lapua brass will not show pressure signs like other types of brass. It is very strong brass and by the time you are getting pressure signs, your pressure may be way up there!

For balistic data, get a copy of Exbal from Lightforce Australia. Or run a drop chart off JBM balistics web site.

[andrewk]

hey wadcutter, the edge is a rem ultra mag improved right?

[wadcutter]

hey wadcutter, the edge is a rem ultra mag improved right?

The .338 Edge is just a .300 RUM necked up to .338 calibre. The .300 RUM case is longer than the .338 RUM case so by necking up the .300 RUM case you get greater powder capacity than a .338 RUM.

Chambered with a long neck also gives extra powder capacity but means that the rifle must be single loaded to take advantage of this. I get about 10 grains more powder capacity over a .338 RUM.

[spindrift]

thanks for the help guys. like i said a project so to be on the safe side a .338 lapua standard would be a safe kit.

[wadcutter]

Spindrift,

What action are you planning to build it on?