Re-barrel to 7 STW or 300 Win Mag??
- Thread starter DIGGER2
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Hey guys, my barrel on my 7mm currently is a 24" length. I know most mags do well with a 26" barrel, so that's why I was going to re-barrel and try something different. The gun has a McMillan stock and Leupold VXIII 4.5-14 scope.I just need to have the action trued up, add a barrel of some kind and I'll have a fine long range big game gun. I appreciate all of your input so far.
I'm still trying to narrow down what caliber is best for me. Ah decisions....
I'm still trying to narrow down what caliber is best for me. Ah decisions....This has been beaten to death but my 24" STW goes just shy of 3300, before rechambering it went 3050. Different powders but both max. This is the same load I've used in all three of my STWs. It went just over 3300 out of the other 26"ers. 24" is just fine. The 340 kicks a lot more than the 30s or 338. 10-12 grs. of powder gotta do something. 225s at 3100 are very flat and hit hard.
7mm Rem Mag, 7mm Wby Mag, and 7x61 S&H Mag are ballistic triplets. Variance between individual rifles will mean more with these then paper ballistics. The STW will buy you another 150-200 fps, generally. As Rick says, if you handload, have a 26" bbl, and re-throat your existing 7 mag you'll get pretty close to that anyway. The Lazzeroni cartridges are a step up from that, depending on which one you choose. The 7mm RUM gets you about all you're ever going to want with a 7mm bullet. Had a buddy with a wildcat 7mm-378 Wby some years back, burned the barrel out in two hunting seasons. Made some amazing fps though. The STW is easy to get/make brass for, it's unusual enough to cause comment on the firing line, and it gains enough speed to be useful. Can't ask for much more from a magnum hunting cartridge. - dan
The 340 is looking pretty promising so far. When you re-barrel and chamber for the 340, does it have the free-bore like the Weatherby rifles have or is this adjustable in a re-barrel to seat the bullets closer to the lands? I was comparing the 340 to the 338 Ultra is there really much difference between the two? ie: is one more accurate etc?? I am looking at the availability of brass. How is brass and barrel life with these cartridges? Do any of you guys run a brake (shudder) on your lightweights?? Thanks for the info so far....
You can have whatever freebore that you choose,but pressures will likely be excessive with factory loads.I had a 257 rebarreled without the freebore,and it went from a 1-1/4" gun to a sub 1/2" gun.
Brass life is fairly good,if you keep the loads reasonable.Barrel life isn't that bad,if you never let the barrel heat up excessively.
I value my hearing far too much to use a brake.Even with earplugs and earmuffs used together,the braked 340wby is louder than I like,and the gases being directed back into your face is really annoying.
My own favorite .338" magnum,was my 338x8mmremmag,which is nothing more than an 8mmremmag case,run through a die to size the neck to use .338" bullets.Ballistics were about the same as the 340wby,and I used much cheaper 8mmremmag brass.I did however have to purchase a reamer,but then again,I always purchased my own reamer when building custom rifles anyways.RCBS had dies in stock,but they did cost more at the time.
Funny, I had 2 338-8MM Mags. many years ago. I was told 340s wouldn't shoot with factory free bore. Plain bull, the 2 340s I had were custon with factory free bore. They were both drills. Use the factory throat. You might want to shoot factory ammo at some point.
- Location
- Somewhere on the Hudson Bay Coast
Some folks just seem to keep the myth alive that faster is always better. Sometimes it is, as your range estimation is less critical the flatter your trajectory is. But in the first place, most modern bottle neck rifle cartridges produce a flat trajectory to their zero range, and in the second place a heavier slower bullet with a high BC will shoot as flat or flatter than a comparatively squat light bullet fired at a much higher muzzle velocity. The ability of a bullet to destroy soft tissue and penetrate deeply does not increase by magnitudes given small increases to velocity when we are talking about bullet impacts at supersonic velocities. When it comes to killing game, bigger is better than faster because next to bullet construction, it is the only sure means of maximizing the wound volume on a big game animal. Thus there are 3 modern cartridges that jump to mind in terms of long range big game shooting with "normal" sized rifles; the .338 Lapua, its sister the .338/378 Weatherby and the .378 Weatherby. Loaded with appropriate bullets, these 3 cartridges represent the pinnacle of long range big game performance with our present bullet and propellant technology.
Interesting the comments about the .340 Weatherby. I had the opportunity to shoot one a year or so ago and was somewhat surprised how pleasant is was to shoot after a long tedious session with my .375 Ultra.
Interesting the comments about the .340 Weatherby. I had the opportunity to shoot one a year or so ago and was somewhat surprised how pleasant is was to shoot after a long tedious session with my .375 Ultra.
My 340 Wby is built on a 700, LW synthetic stock, Ron Smith gain twist bbl. It has the recomended freebore. Very accurate with 250 gr Speers, less so with the Noslers I hunt with. It probably weighs 7 pounds or so scoped, recoil is sharp and nasty, but it's a hunting rifle, so that's alright. It actually recoils more then my 338 Lapua, but that's because of rifle weight. When I was fireforming brass from necked down Win 375 H&H (340 brass wasn't too common back then), I ran out of volunteers at the range in short order, lol. Still, it kills amazingly well, as do all the fast 33's. - dan
As far a freebore goes I would not be concerned with that.
Unless you can hold the beast better than 3/4 minute, a custom barreled 340 will shoot better than you can....I'm not talking about 100 yards either.
The freebore also allows you to shoot factory ammunition.
FWIW the 338Ultra also has significant "freebore" and it shoots as well or slightly better.
The 338Ultra or 338Edge are a completely different animal with significantly more recoil (way faster and snappier) than the 340 with (at best) difficult to ascertain upside. The 338/378 comes in a heavier rifle so recoil is OK, but I see little use for the slight increase in velocity.
Bottom line is more recoil adds to the difficulty in long range shot placement and (depending on the shooter) the extra recoil may make the faster cartridge LESS effective at long range.
With a range from the 338Federal to the 338/408ct we have a lot of choices in .338 chambers. I have owned or do own most of them, but I think the 340 is the best all around .338 there is.
I spent ten years with the 340Wby and it is a fantastically well balanced round in every way.
Good luck Bubba!
Unless you can hold the beast better than 3/4 minute, a custom barreled 340 will shoot better than you can....I'm not talking about 100 yards either.
The freebore also allows you to shoot factory ammunition.
FWIW the 338Ultra also has significant "freebore" and it shoots as well or slightly better.
The 338Ultra or 338Edge are a completely different animal with significantly more recoil (way faster and snappier) than the 340 with (at best) difficult to ascertain upside. The 338/378 comes in a heavier rifle so recoil is OK, but I see little use for the slight increase in velocity.
Bottom line is more recoil adds to the difficulty in long range shot placement and (depending on the shooter) the extra recoil may make the faster cartridge LESS effective at long range.
With a range from the 338Federal to the 338/408ct we have a lot of choices in .338 chambers. I have owned or do own most of them, but I think the 340 is the best all around .338 there is.
I spent ten years with the 340Wby and it is a fantastically well balanced round in every way.
Good luck Bubba!
Hey thanks to everybody again, you guys a great. I appreciate all of your information you've given me. I have to ask though, what length of barrels are you guys using. I currently have a 24" barrel and it handles quite well, but do you guys recommend a 26" tube for the 340? Thanks....
I think a 26" is perfect for the 340, but I know a guy who hunts with a 24" and he's happy. Of course, he doesn't own a chronograph. - dan
Why worry about the free bore? Just seat the slugs .030 off the lands and you are good to go.The remington action is plenty long enough for this.Dont worry about the COL length in a reloading manual. Or seat the slugs so that they are .020 or .030 short of the mag length for your rifle.As for brass buy remington bulk brass in 300WBY,run it through a lee tapered sizing die and fire form and you have 340 WBY on the cheaper side. I did this and only lost 2 rounds out of 100 from neck cracking issues..
I have had Weatherby chamberings in 700 actions,where the bullets were over .100" off of the lands when seated as long as the magazine would allow.Accuracy was very disappointing with such a long jump to the lands.However,the accuracy was decent when the bullets were seated to just off of the lands,but that meant using the gun as a single shot.
- Location
- Somewhere on the Hudson Bay Coast
Hey thanks to everybody again, you guys a great. I appreciate all of your information you've given me. I have to ask though, what length of barrels are you guys using. I currently have a 24" barrel and it handles quite well, but do you guys recommend a 26" tube for the 340? Thanks....
Choose a rifle that is suitable for the hunting you intend to do. If you anticipate only longish shots in open country the 26" barrel is fine, but an 18"-20" barrel is better in heavy timber or when crawling along grass tunnels looking for a grizzly on Kodiak. On the other hand, particularly when loaded with heavy bullets, a .338 doesn't give up much velocity or range when a short barrel is chosen, over a long. FWIW, I prefer short barreled rifles, but thats just me.
+1. Some Wby chamberings use a LOT of freebore (up to 3/4" in some of the old ones, less in newer guns). I've always been able to find a load that worked for hunting in all the Wby chambered rifles I've owned, but I wouldn't take one to the next BR match. - dan
That's pretty good. Mine has a 26" bbl and I get 2940-2950 with 250 gr bullets. I had hoped that the 338 Lapua would push this faster, but from a 26" bbl TRG-S, I get 2970 with the same bullets. To get those bullets faster, I had to play with a 338-378 Wby, a 338-416 Rigby Improved and an Abe Express. And you burn a lot more powder for not much gain. Really, the best way I found to get the 33 cal heavy bullets going quicker was longer barrels. But then they become a pita to use in the field. No free lunch, sadly. - dan
Thanks for the replies again fella's. My main purpose with this future build is to have a rifle that weighs around 8-8.5lbs with a barrel short enough to keep it handy in the field, but keep velocity loss to a minimum. The ultimate goal here is to be able to hammer a moose sized game at 500yds or less, and be able to practice with it, without rattling my teeth loose. So I hope the 340 won't be to violent to shoot. Thanks again.....Scott
