This subject kinda stradles several boards but because I am building this rifle I felt it most suited to this board.

I've been working on a .338 WM for a while now (since last winter). Have just about finished up the receiver and now I'm wondering if it is really worth the extra effort to choose the WM over the -06. You might recall that I'm building this on a M98 action.

My confusion stems from the fact that I can't seem to get a clear idea of how much velocity difference there is between these cartridges. The load data seems to vary quite a bit. I've seen manuals that give the WM a 250 fps advantage with 250 grainers and some manuals that give the WM less than a 100 fps edge.

From my point of view, a 250 fps gain IS worth the trouble. But, less than 100 fps ain't!

What does your real world experience say?

Z1R---

There's another way to look at it.

Think of picking cartridges by the ratio of bullet weight to powder capacity.

Under that system a 338-06 shooting a 210 Nosler has the same "score" as a 338 Win Mag shooting a 250.

If you want heavier bullets pick a bigger case.

For the LEAST amount of trouble making a CFR feed (push feeds are much more forgiving) ALWAYS pick the case closest to what it was made for. That means the 338-06 is very nearly a drop-in cartridge for an 8x57 M-98......it IS a drop-in for a 30-06 M-98.

z1r, Rule of thumb. .275 grain Speer for the shared bullet, if you can get the .338 Mag shooter to handicap you 75 yards, sights for 100 yd, Your bullet drop with .338x '06 and his will be virtually the same at 200,300 and way out there. Different wt. bullet and the handicap will change but not overly much. Though you ought't need the extra rounds ,5 in the mag box is an easy go for you versus the usual three for the Mag shooter. My Al White engraved .333 x '06 was about 10 years old when my operatives smuggled my first sample ammo and fired 338 Mag cases from the land of Olin and caused me some vague feelings of inadequacy. Rapid assembly of a test vehicle and quick trips to the predecessor of Cascade at Lewiston, with both rifles soon calmed that feeling, Those tests were with same wt. bullets. A careful reading of the Hornaday drop tables will show you what I have stated,but with the advantage of more comparisons weight for weight. If you enjoy piddling with various loads-rainbow chasing- you might not like the .338 x 06 as it is even less finicky than the mag, therefor dull,dumb and uninteresting. It is kind of neat though to head out into the hunting fields with such a dependable tool where the only part you got to worry about is that sometimes loose nut behind the butt-plate.

I just received my latest Hodgdon reloading manual and I was suprised to see that the .338-06 was about 100 fps slower in all bullet weights up to including 250 grain bullets. Hodgdon has alot of different powders, and pressure testing does not lie. The .338-06 is a super efficient cartridge. The .338 Winchester is no slouch either.

Thanks gentlemen! That's kinda what I was hoping you'd talk me into.

I just barely seem to find the time to do any gun related work lately. Tackling the Magnum conversion, while something I will eventually have to learn, is not nearly as high a priority now as having a working rifle. Emphasis on working!!!

Now for the easy question: What parent brass do you prefer ?

Okay, the .308 is great, and so is the 30-06..

Oh, sorry- we're talking about .338 cartridges

If you are going a little longer, the .Mag has the edge. At 250 yars, I bet the moose won't know the difference!