mnmike59 wrote:EJSG19 wrote:that is one hell of a caliber to make your first center fire cartridge with. I salute you.
I have no idea what I'm getting myself into! My neighbor Geezer43 has Skillz, He volunteered to help.

Problem 1: You got a glossy ad for an AR-15 platform for .338 Lapua, and NO PROOF that it WILL shoot as well as a bolt gun. Strike one!!
Problem 2: The barrel length is right, and the twist is right, but the powder isn't. .338 thrives on Retumbo and RL-25, and near 100 grains of each. RL-19 is too fast, and 75 grains of RL-19 is going to leave a lot of empty space in the case, which could lead to a detonation and a blown gun. Strike two!!
Problem 3: You're buying an $8000 rifle fully equipped, and you OBVIOUSLY don't have a reloading manual that costs less than 30 bucks to tell you what proper loads for a 338 Lapua are. STRIKE THREE!!
As you said, and you are absolutely right, you have NO idea what you are getting yourself into, and there are some very subtle twists to shooting .338 Lapua from a semi-automatic rather than a bolt gun that could get you into BIG, BIG, trouble when you reload the cases for the second time.
You need to back off from your gun lust and take some chill pills before you get yourself seriously hurt.