338 lapua AI 40 degree load help

[Jim See]

Fireforming loads with 92 grains of H1000 and 300 smk shot into less than 1" at 300 yards at 2700 fps

Using the formed brass I am strugling to stay at 3/4 moa.

using the area of 96-98 grains of H1000 and velocity in a 29" barrel is around 2800fps. like I said accuracy is sub-par.

Is there a higher pressure node I should be in? not sure how high I should go.

loaded up 104 grains of Retumbo today and will give that a go tommorow.

any advice?

 

[Broz]

Jim I think you need to go higher. I have run 92.5 gr of H1000 with 300 SMKs in my standard Lapua. You should get close to 2950 with H-1000 from the AI. 100 gr of VV N-570 will get you close to 3000.


One more thing. 90% of the .338's I have done will take a 3/4" load at 100 yds and print the same 3/4" group at 300 yds.

I don't spend much time at 100 yards with a 338 and a 300 Berger or a 300 SMK.

Jeff

 

[Jim See]

Thanks Jeff, Since my move I am limited on a longer range to shoot at. having 600 yards outside my back-door spoiled me.

I will shoot them at 300, I have a spot to confirm trajectory at 1100 but it takes a few phone calls to get in. The only bergers i have is the original 300 OTM that i picked up when they first came out. I will shoot the Retumbo load and work it up again if this trial doesn't perform.

Elk hunt in less than 2 weeks and I'm cutting it close.

 

[Broz]

Thanks Jeff, Since my move I am limited on a longer range to shoot at. having 600 yards outside my back-door spoiled me.

I will shoot them at 300, I have a spot to confirm trajectory at 1100 but it takes a few phone calls to get in. The only bergers i have is the original 300 OTM that i picked up when they first came out. I will shoot the Retumbo load and work it up again if this trial doesn't perform.

Elk hunt in less than 2 weeks and I'm cutting it close.

Jim, just stick with the SMk's. I think you would be on the edge of the Gen 1 Berger 300's coming apart. You should get a good load with Retumbo and the 300 SMK. Just watch for the Retumbo spikes. Probably won't be an issue with the AI and fall temps. .065" off lands was a sweet spot for me with the SMK. And they liked a max load.

Jeff

 

[Jim See]

Jeff, I worked up a good load that is running 3009 with 300 OTM, (2nd generation found a couple boxes.) using Retumbo.
I showed some slight ejector marks at 3060 so backed down a grain and a half. test shot 1" verticle at 300. I'm calling that good for elk ;-)

This weekend I am shooting 600 and 1100 for trajectory validation and going hunting.

Thanks for the help,
Jim

 

[Broz]

Jeff, I worked up a good load that is running 3009 with 300 OTM, (2nd generation found a couple boxes.) using Retumbo.
I showed some slight ejector marks at 3060 so backed down a grain and a half. test shot 1" verticle at 300. I'm calling that good for elk ;-)

This weekend I am shooting 600 and 1100 for trajectory validation and going hunting.

Thanks for the help,
Jim

That will work Jim. Glad you got her going, but I knew you would.

Good luck on your hunt.

Jeff

 

[kaseyfied]

dsmmit.. u guys r going to make me build another lapua with those velocities!!!!!!

kasey

 

[Jim See]

I must say mine is a single shot with a .250" free-bore.

 

[RockyMtnMT]

Boy do I understand that feeling of leaving in two weeks and still trying to get the load working. Feels real good when it starts to work.gun)

Steve

 

[Kiwi Greg]

dsmmit.. u guys r going to make me build another lapua with those velocities!!!!!!

kasey

If you want to see some velocity give RL33 a go


I see that you are already

It really perks the 338 Imp up.

 

[JeffVN]

Retumbo & 300 gr. SMKs worked fine in my 338LM Improved, but she liked VV570 a lot better & a bunch faster. Unfortunately VV570 is darn near impossible to find these days, so I am looking to test some RL-33 next.

JeffVN