A Wby Accumark in .340 WBY MAG
First off, let’s get something out of the way that’s annoying! It’s the opinion of a few hunters/shooters that there’s not enough difference between the bores of a .308-cal (.300 mag) and a .338-cal (.338/.340 mags) to matter. Someone of reputation has stated that the gap is only the thickness of your fingernail! Well, yes, that may be. . . . BUT that’s all the way around the bullet that amounts to 0.08969 sq-in. vs 0.074 sq-in, or 21% greater in cross-sectional area for a .338 vs .308! That’s not nothing, but something! In addition, bullet weights can be much heavier in a .338″ : 300 grs vs 220 grs, and SDs of .375 vs .341 on the high end. And that’s not all! In the Win Mag only series of magnums, a 220gr/.308 vs their .338 mag, 250gr, have about the same MV, meaning: the .338 develops about 500 ft-lbs more at the muzzle and 11% more in momentum! And while the .300 is usually limited to 220 grs, the .338’s heavy is a 300gr! So the notion that a .338 bore is “only” a fingernail thickness greater than a .308 bore, there’s much more to it than fingernails. A .338″ bore is also more efficient than a .308″ of the same case capacity – it’s called “ballistic efficiency”, or “expansion ratio”. That’s why Roy Weatherby offered the .340 Weatherby (.338″) even though his .300 Weatherby was already famous. The .340 is simply the .300 (.308″) necked-up to .340 (.338″) with an increase of 500 ft-lbs at the muzzle while burning the same amount of powder! That’s in addition to all the other advantages.
And that’s why I chose a .340 Wby for my moose rifle in Northern Ontario. From my 26″ I was getting a 10 year average from those 250gr Nosler Partitions of 2997 fps/4986 ft-lbs. And the 80 once-fired .375 H&H cases lasted a full decade, and I never discarded a single one! At 1000 rounds of that ammo, each case was reloaded an average of 12.5 times at max PSI !
<My .340 Wby was a Browning A-Bolt SS in LH, converted from a .338 Win Mag by my gunsmith using a .340 reamer. It had a 26″ barrel. The load on this occasion was a 250gr NP at ~ 3000 fps. Powder was RL-22.
Some hunters/shooters claim they could do the same thing with a .30-06. At 600 yards? Up in the Far North of Ontario, some clear-cuts could easily extend to +1 kilometer . . . . 1 K = .6214 mile, or nearly 1100 yds, and adult moose were crossing those places! A 600 yd shot was possible but not beyond that for me, personally. And not likely for my .300 Win backup.
Another way of looking at such matters: There are places, and other good enough reasons, for Roy to have introduced the .340 back in 1962. It would add 160 fps to a 250gr over the 1958 Winchester .338 at 2700 fps. And it has only improved with time and better ballistics from newer powders and bullets with higher BC’s.
If we compare the .340 Wby with the much newer .338 RUM or Lapua, they really have nothing to offer over the veteran .340 Wby.
The .340 WBY in a left-hand 60* bolt lift that was extremely smooth in operation. The rifle is a Browning A-Bolt SS rechambered from a .338 Win to .340 Wby.
I’ve mentioned some results from mine: a 250 NP at ~3000 fps/ ~5000 ft-lbs at the muzzle. At that time Weatherby was offering the same 250 NP from their .340 at 2860 fps as a factory load = 4540 ft-lbs. Yet sometime later than my adventure to the “Far North” on a moose hunt, they upgraded their 250gr NP load by 90 fps to 2950 fps/4830 ft-lbs. There’s little doubt that they previously knew the .340’s potential but since they had no competition at 2860 fps, there was no reason to increase its performance. But by then my own results were publically known by correspondents, plus other .338s were coming on line, so they boosted theirs by 90 fps for their best load of that 250gr Partition.
Here’s a recent select printout from Nosler’s No.9 of results from more newly introduced .338-cal rifles firing their 265gr and 300gr ABLRs in comparison with the older .340 Wby Mag:
33 Nosler: 265gr = 2850 fps/4779 ft-lbs (max); 300gr = 2566 fps/4386 ft-lbs (max) 26″ barrel.
.338 RUM: 265gr = 2869 fps/4843 ft-lbs (max); 300gr =2655 fps/4695 ft-lbs (max) 24″ barrel.
.338 Lapua: 265gr =2923 fps/5027 ft-lbs (max); 300gr =2751 fps/5041 ft-lbs (max) 24″ barrel.
.340 Wby Mag: 265gr =2907 fps/4972 ft-lbs (max); 300gr = 2727 fps/4953 ft-lbs (max) 26″ barrel.
- As I see it, those 4 all fit into the same class of ballistics. None have really added anything in ballistics over and above the old warhorse – the .340 Wby Mag. The Lapua beats it by a smidgeon, especially from a 24″ but at the added costs in $$$ and recoil.
- The .340 gets 2727 fps from the 300gr ABLR from a meager 75 grs of IMR 4350 – an old standby! The .338 Lapua takes 89 grs of RL 33 to attain 24 fps more. Difference in recoil if rifles have same weight at 9 lbs ready without a brake: 55.6 ft-lbs for the .338 LAPUA; and 48.7 ft-lbs for the .340 WBY.
I’ve read somewhere recently that the .340 WBY is hardly mentioned anymore online or in print. If that’s true, then someone needs to wake up, give their head a shake and start a .340 revival, because it’s too good to lay dormant . . . . . It’s as good as the others, and better than many!
I see one or two for sale at EPPS from time to time, but pricing is a bit on the high side – perhaps to be expected. In fact, a number of years ago somebody who’d bought mine placed it there for sale. It was gone rather quickly as it wasn’t a Weatherby product.
If you have a taste for a powerful rifle in .338-bore, they don’t come better than a .340 Weatherby Magnum (except for the humongous .338-378 Wby). Mine only digested handloads made from once fired .375 H&H brass – they lasted for the duration of that rifle under my ownership and care for 10 years. They cost me $ 0.0 dollars, granted to me from a fellow going to Africa on safari. . . . 4 boxes of 20.
Those 80 once fired Remington .375 H&H cases were reloaded an average of 12.5 times at max PSI, and not even one was discarded.
< .375 H&H on right; .340 brass case fireformed in my .340 from .375 H&H brass on left.
Hagel said he liked the .340 better than a .375 H&H for North American hunting of large moose and bear. He liked the flatter trajectory of the 250gr/.338″ at 2900 to a 300gr/.375″ at 2500 – 2600 fps. Would that matter today? His hunts were mostly in the West with wide-open spaces. . . mine have been mostly eastern where a long shot would be significantly shorter, except for the “Far North”. Yet I do agree with him on the principle of being equipped and ready for any unexpected and less than normal conditions, regardless of location or game.
A Hill Country .340 Wby -26.5″ barrel with brake- at EPPs for ~$4500.
I think Hagel would be even more impressed with the .340’s results today: from Nosler 9
Conditions are normal for my area in late fall:
300gr ABLR – BC = .785
MV = 2727 fps/4952 ft-lbs
100 = 2614 fps/4549 ft-lbs
200 = 2503 fps/4173 ft-lbs
300 = 2395 fps/3821 ft-lbs
400 = 2290 fps/3493 ft-lbs
500 = 2187 fps/3186 ft-lbs
600 = 2087 fps/2902 ft-lbs
700 = 1990 fps/2637 ft-lbs
Unfortunately, there’s no .375-cal bullet that comes close in BC (Ballistic Coefficient). Currently, the best in .375-cal is .480 – .485 BC for the 300gr Sierra and 300gr Nosler AB respectively. When and if started at the same MV (2727 fps) they just can’t keep up with the 300gr ABLR in .338-cal.
Till the next . . . .
Shalom
BOB MITCHELL
Lovin' The Big Bang 