340 or 338-378

[kimmer82]

The .340 is expensive to feed. Brass is pricey for the quality (unless you like to fireform). The .338 Ultra will get you into better ballistics, without a belt and much cheaper to shoot. I love the Mark V action, but really overkill and hard to find upgrades for. I sold my .340 to get my RUM and am very happy with it. I still like the .340, just not worth the cost when the RUM does it better for cheaper.
If you want to shoot real long range (beyond 400 yards) you will want 225 grain bullets and up. I would start by looking at the 225 TTSX or Accubond. The 250 and 300 grian Bergers are impressive in the wind.

from my experiences with 340WB.. is not expensive to shoot at all. Can be equipped so many hunting and match bullets with almost no difference with 338 LM.
I just love shooting 340 WM Accumark, already burnt the barrel off after 1 year. It is currently getting re-barreled in Krieger to be shot again.

Also "real long" range needing heavier bullet is a myth in my mind. Since we are not going to snipe Heads off at 1000+ yards, you can shoot 1000 yards with 308 or whatever smaller than 225 grains of bullet.
Yes, you will have a huge difference on Energy(ft-lbs) as the bullet travels longer on 168g vs 225 but still but still accurate.
400-600M will be easily achived with 30-06 or any caliber realistically.
Just my experiences with longer range shooting but may differ with others i guess.

 

[tracker87]

I started loading for the .340 when I was fairly new to the game, and since then never thought of sizing 300 wby (duh).

The .340 wont run with the lapua or rum, it will be close, but still 100-200 FPS slower with the same bullet at the same pressures.
The Ole' 30-36 will do fine for long range shooting, I cant argue that. While energy is important, the main reason for heavier bullets is shooting in the wind. They just move less. I've gone to 1100 yards with 225 SSTs, but its easier with 300 bergers.

 

[saskcop]

I shoot a .338 RUM and I don't think that there is a moose, elk or bear out there that would know the difference between that and the .340. Go for the .340.

 

[guntech]

What's wrong with a belted case?

Keep in mind the belted case was made for the .300 H & H... a long tapered case. So it was made to insure correct head clearance of the cartridge when in a correctly head spaced chamber. This would have been achieved by making an exact measurement from the front of the belt to the rear of the case of .220". In reality they have not been able to manufacture brass that accurately. I have never seen brass measure up to that figure of .220". Often it varies between .214" and .217"... so there is a lot of head clearance and brass stretching on the first firing.

The belt does not add any strength to the case and does nothing to assist in feeding and in modern designed 'blown out' cases is not required.

 

[kimmer82]

yes heavier does gets less effected, I forgot to mention, my 340 performed just as stock 338LM only because i had 30" barrel length and was getting about the same FPS with my 338LM. It is getting replaced with krieger but still deciding on length....
maybe go with 26-28" and than i am sure it will probablly have 50-100 fps difference with 338.

 

[7 REM MAG]

thanks for the input guys, c-fbmi thats a good lookin rig, when you form do you just neck down to 338 and then fireform the brass or do you have to turn the necks? Do you have to create a false shoulder?

 

[Splatter]

So... given equal length barrels how much does the .338 WinMag give up to the .340Wea?

 

[guntech]

I don't know about equal length barrels but I think a .338 WM will do fine with 22 to 24 inch barrels... and a .340 should really have a 26 inch to use that big case... and my personal preference is a 338-06 with a 22 inch barrel... and it would still work well with a 20 inch. The bigger the case the longer the barrel as far as I am concerned.

 

[c-fbmi]

thanks for the input guys, c-fbmi thats a good lookin rig, when you form do you just neck down to 338 and then fireform the brass or do you have to turn the necks? Do you have to create a false shoulder?

Negative on false shoulder as the 340 shoulder is farther down than the .375. Forming depends on the brass, when I could get Win in 375 all I did was FL size and shoot, then trim and away you go. With the Rem 375 I have to move the shoulder back with 338 WM die first then FL in the 340 die to form the radius and then load and shoot. Rem brass buckles when trying to do it in one step. Actually I don't even use the 340 die any more I just bump the shoulder back with the 338 WM die until the bolt closes with a bump and load and shoot. Voila, perfect 340 brass for the price of Rem 375 cases. Have never had to turn necks in the 3 X 340s I've made brass for. I do the same with my 300 WBY, I use W-W 300 H+H and just load and shoot a good max 300 H+H load and perfect 300 Wby comes out of the chamber. I have never bought 1 single piece of Wby brass and I have owned many different Wby chambered rifles. I made my 7mm Wby from 7mmRM and I make all my 257 Wby from 264 WM.

 

[7 REM MAG]

ok thx a lot, doesnt seem much more intensive than making brass for my 270 ai, is there a reliable forming method for 338-378 or is that a suck it up and pay for them situation?

 

[c-fbmi]

ok thx a lot, doesnt seem much more intensive than making brass for my 270 ai, is there a reliable forming method for 338-378 or is that a suck it up and pay for them situation?

The 378-416-460 Wby are proprietary cases and cannot be formed from any other case. Needless to say the same goes for both the 30-378 and 338-378.

 

[SuperCub]

Keep in mind the belted case was made for the .300 H & H... a long tapered case. So it was made to insure correct head clearance of the cartridge when in a correctly head spaced chamber. This would have been achieved by making an exact measurement from the front of the belt to the rear of the case of .220". In reality they have not been able to manufacture brass that accurately. I have never seen brass measure up to that figure of .220". Often it varies between .214" and .217"... so there is a lot of head clearance and brass stretching on the first firing.

The belt does not add any strength to the case and does nothing to assist in feeding and in modern designed 'blown out' cases is not required.

All true, but most reloaders (myself incl.) would neck size those belted cases anyways thus headspacing on the shoulder the same as the new beltless cases. Cases last longer, no feeding problems, good fit and function.

Belted or unbelted, I treat them the same and have good luck with each. I just don't buy into the marketing battle cry that belted cases are inferior.