There are many .338 caliber cartridges on the market today. There is the 338x57 O'Connor, .338 Lapua Magnum, .338 Winchester Magnum, .338-06, .338 Remington Ultra Mag, and Shawn Carlock's .338 Edge… However, there is one 338 cartridge that is relatively new and impressing all who have had the opportunity to shoot it, and that’s Jim Sloan’s 338 Norma.
Mr. Sloan, (Texan Ballistic Guru) designed the 338 Norma loosely based on the 416 Rigby case and it is specifically designed to shoot the 300 grain Sierra Match King in a Remington 700 Long Action; without deep seating the bullet. The reason that the 338 Norma carries that title is because Mr. Sloan and Norma worked out an arrangement to have Norma manufacture the cartridge for entities inside the United States. As such, Mr. Sloan receives a small residual payment for his contribution. Read More...
This is a thread for discussion of the article, 338 Norma Review , By Ward W. Brien. Here you can ask questions or make comments about the article.
Is this the same cartridge as the .338 Norma Mag that I have read about elsewhere?
Why did you go with a faster twist barrel over the original 1:9.4?
Also, was this twist (1:9.4) chosen over the standard 1:10 due to the shorter barrel and reduced velocity over that obtained from the longer barrels used typically?
Do you think a 1:9.6 would also be adequate for this cartridge?
This is the same cartridge you may have been reading about.
Most of the guys that are building these feel that the optimum twist rate is 1:9.4.
However, the 1:9.1 Works Perfect. I started with my barrel length at 28" and obtained
2780 fps. (The 10" group at 1536 was due to a full value left to right wind that you could not see. No indicators whatsoever. If we had been shooting without that wind, the group would have been pretty small...
I then cut the barrel down to 24" and obtained a velocity of 2710 fps. That's not much of a velocity loss for four full inches.
Now I have cut the barrel down to 22.8", and with 1:9.1 twist rate I get two full twists and my accuracy is still phenomenal. I have not chronoed the loads yet however I increased the charge to 83.5 grains of R22 with Fed 215M primers, and will work up in .2 increments starting tomorrow.
On the second page of the article, where it shows the target and two bullet holes... That was made when I was breaking in the barrel. The hole on the left is round 21 and was shot out of a perfectly clean barrel. The hole to the right is round 22 and 23 out of 23 Total.
Thanks for the article.
I have 2 custom rifles based on the 338 Norma Mag.
Found out about the cartridge last July. I thought the 338 was a propriotory cartridge, so I necked it down to a 30cal, and improved the shoulder angle. My gunsmith ( SSG/ Nathan Dagley ) got the reamer back in Sept 08 and built me a rifle. I call it a 300 JAZZ, and it is an extremely accurate rifle. Shot a 2 1/2 " group yesterday morning with it at 723 yards, with only 1" in verticle. I am shooting 240gr SMK @ 2840fps with no pressure signs.
After talking with Mr. Sloan and gaining permission to buy his reamer, I had SSG make me a 338 Norma Mag as well. I received my 338 Norma Mag from SSG/Nathan Dagley last week. I have not shot it yet, but expect it to be just as accurate as my 300 JAZZ.
What I like about these cartridges is that I can shoot the long VLD bullets in the 30cal, or the 300gr SMK in the 338 and use the standard magbox, and not have to seat the bullets deeper in the case. Jimmy Sloan's design for that is right on the money.
I also feel that because of the design of the case that the cartridge will be forgiving in load developement.
After pressure testing was done in my 300 JAZZ, my load developement went very easy. My first loads were shooting .75 MOA out to 725yards. Since then I have done alittle tuning and am now 1/2 MOA or less out to 750yards.
I think the more people find out about the 338 Norma and it's offspring, the more popular it will become.
The 338 Norma cartridge inspires allot of thinking.
As Trueblue mentioned, necking down the 338 Norma to a 30 caliber is an awesome idea, and it is my understanding that there are others out there doing it as well. When I think about shooting the 338 Lapua, I have to honestly ask myself how ballistically effective is it against either a 338 Norma, or a 300 win mag with the use of 185 grain Berger's VLD's?
Every ballistician's intentions are good, and all ballistician's do their best to get their project(s) shooting as accurately as possible. However, the 338 Norma has been shooting exceptionally well no matter what length my barrel is and at distances just short of a mile.
So for me, it has become my personal favorite. Build a Gas Gun chambered for this cartridge, and an experienced Shooter can own the mountain.