Long Range Hunting Online Magazine

Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels & Ballistics

Rifles, Bullets, Barrels & Ballistics Applied Ballistics


Help me buld a big .338......

LinkBack Thread Tools Display Modes
Unread 10-06-2008, 12:17 PM
Silver Member
Join Date: Sep 2005
Location: Kalifornicated
Posts: 390
Help me buld a big .338......

After a lot of thought and research I am going to build one of the various .338's. I have spent a couple of hours running ballistics on JBM, thinking about what level of performance I want, quality of brass, inherent accuracy etc, etc.

I was strongly leaning towards the 338 Allen. I love all that power and as a drag racer I love horsepower !! However, at this time I am thinking I am going to go with something with a little better barrel life. I want something with more power than a 338 Lapua. I have a 300 Wby and 30-78 Wby, and don't think the Lapua can out do the 30-378 by enough (if at all) to justify it. So...... I am thinking 338-378 Wby. Here is why ) I am open to suggestions on other .338 cartridges !!

I think with a 32 in barrel I can get 3000 fps with a 300 Berger or SMK
The brass and precision dies are very available.
It is a proven caliber

I am looking for recommendations on barrels and actions. I am leaning towards a Hall action with a Shilen barrel. Also looking for a gunsmith with a turn neck 338-378 Wby reamer. I am not interested in a standard chambering.

I am all ears to those with experience with the 338's

Ideas ?

USMC Scout Sniper 88-94
Instructor 1st. Mar. Div. SS school 91-94
Reply With Quote

Unread 10-06-2008, 01:43 PM
Silver Member
Join Date: May 2005
Location: Montana
Posts: 441
Re: Help me buld a big .338......

I have the 338 AM and have never regreted it. Why not go for the best right out of the gate? I did. Not that much more $$$ and you have that top fuel dragster that you wanted.
I know, I didn't help much, sorry!
Reply With Quote
Unread 10-06-2008, 02:32 PM
Platinum Member
Join Date: Feb 2007
Location: Townsend, Montana.
Posts: 8,644
Re: Help me buld a big .338......

I use to race too. I built the Lapua. You don't have to rev a Big Block.

Reply With Quote
Unread 10-06-2008, 02:37 PM
Platinum Member
Join Date: Nov 2005
Location: Texas
Posts: 1,845
Re: Help me buld a big .338......

I shoot the 338 Slowpoke (based on a 338 Lapua) in several rifles for hunting and in competition. In the latest hunting rifle used for ELK hunting the 2 weeks that I had to work up loads got the 250gr SMK to 3049 without excessive pressure signs and up to 3179 WITH a hard to open bolt!! The 3049 load shoots .4 at 300 with no brake and let me tell you it jumps 4 inches off my front rest. Rifle and scope weigh 11.2 lbs -- knew I should have not loaded that much WMR and H1000 on the over pressure loads!!!!!

Anyway I will be glad to send you the print of the cartridge to look at if you are interested. Speedy helped me with this and we got Kiff to build the reamers to chamber with and make the dies.

Just so you will know on several loads I have worked up on several barrels it is not uncommon to see shot to shot deviations (5 shot groups) in the 25 fps or less range.
The Truth Is Not Always Good For Business!!
Reply With Quote
Unread 10-06-2008, 04:49 PM
Gold Member
Join Date: Sep 2003
Location: Nebraska
Posts: 810
Re: Help me buld a big .338......

I would spend what ever extra there is to get the 338-408 over the 338-378wby imp 40deg.

Ive built many of them in the past and wont do them any more, the brass is not very good for the high pressures your looking at running. The guys that have them wby's ive built are getting 2750 in a 27" barrel, most accurate load. long barreled rifles are are in the 2900fps range. Most end up backing the loads down to save brass life.

If your spending mucho bucks for a custom rig the price of custom dies and brass are a small factor. Barrels are considered a consumable part of the whole rifle, you can load a 338-408imp to 3000fps and that would be a light load, barrel life would be as good or better than a 338-378 using the faster burn powders to achieve anything close to 3000fps.

In the end its all about accuracy first, most guys ive talked to with the hotrod 338-408's
tell me they have settled for 3200-3300fps for the most accurate loads with the 300smk bullets. I seen the article where Joel Russo fired the group from his 338Bigbear, 3.8" at 1650yds, (if i remember right) His load was 3250fps. Ive ran my personal rifle up into the high 3400's, it still shot great but the brass didnt like it. I have backed my loads to 3300ave speed and shoots lights out for a lighter hunting type repeater rifle.

I push the 338snipe tac when ever i can to the guys who want the ultimate in the Big 338's
Kirby's 338am is another choice for the hotrods. There is only two 338's i will build, the Lapua and its wildcats, or the 408 case and its wildcats, i want nothing to do with the belted mag cases, ie Wby.


"Let the good times roll"
Reply With Quote
Unread 10-06-2008, 08:47 PM
Platinum Member
Join Date: Jan 2008
Posts: 4,400
Re: Help me buld a big .338......

I have thought of the 338 as well and I decided on the Lapua. It is more practical in so many ways and like BROZ said you dont have to REV a BIG BLOCK. So well put BROZ!
Reply With Quote
Unread 10-06-2008, 08:52 PM
Official LRH Sponsor
Join Date: Jul 2006
Location: Harrisburg, PA
Posts: 2,758
Re: Help me buld a big .338......


I too am a drag racer, currently run a 1/4 mile Alcohol car. I'm used to horsepower, lots of it.

And I like horsepower in my rifles also..

Black Diamond is absolutely correct. Build your .338 on the .408 case and improve it. Realistically, you will see 3200-3300 fps with a 300 gr bullet and a 33" barrel. Your accuracy will fall somewhere around the 3200 mark. You can't get there with the .378 or the Lapua case. Barrel life may be a bit shorter than the smaller .338's but that's the trade off for the additional horsepower.
Reply With Quote


Thread Tools
Display Modes

Similar Threads for: Help me buld a big .338......
Thread Thread Starter Forum Replies Last Post
338 buld ?? darrindlh Gunsmithing 3 03-29-2010 02:49 PM

All times are GMT -5. The time now is 03:40 AM.

All content ©2010-2015 Long Range Hunting, LLC