If I buy a 340 in a Mark V, can I spin a 338 Win mag barrel on it? Will it still feed properly?

Can always make up some dummy rounds to play with. I have had a long association with my 340. It wouldn't shoot, I tried everything and then... I chopped 2" off the barrel and it started shooting sub MOA, . Why the change may I ask? I love both btw

Sorry I just realized you have implied you haven't purchased it yet. IDK

Why would you want to do that?

I have owned both, and found the .340 to be a better cartridge.

I should try some 338's in my 340 MKV and let you know on feeding.

If you shoot factory ammo however the cost can be high.

I own a MkV in 338 Win Mag, so I'm sure you could find one in the US. It is a stainless steel synthetic. Crappy stock, but otherwise good.

I think the 340 Wby may be one of the best calibres ever by the way....

The Mark V action is available in .257, .270, and 7mm Weatherby, all of which are similar in LOA to the .338 Win, so unless the Mark V for the .340 is modified in some way I can't see why the slightly shorter .338 Win wouldn't feed just fine.

But the greater question is why? If you simply want a Mark V in .338 Win then you can use any Mark V currently chambered for one of the above Weatherby calibers instead of having to use only a .340 Mark V.

BTW, I've owned both calibers in identical rifles. The .340 provided no significant advantage in velocity over the .338 and was more temperamental in the accuracy department. Despite only providing 50-75 fps more velocity, it kicked noticeably more with more muzzle blast (and remember, these were identical rifles, both with 24" barrels). The brass was also much more expensive. I happily kept the .338 and sent the .340 down the road.

quote:

Originally posted by ar corey:
If I buy a 340 in a Mark V, can I spin a 338 Win mag barrel on it? Will it still feed properly?

On taking a .257 Wby barrel off a Lazermark (to put a 7mm Rem Mag barrel on) Bobby Pitchford told me he has to cut a significant number of barrels off Mark V's.

Might not be a "spin it off" thing for you...

My 24" 338 pre-64 Custom 70 gets right at 2650 with my handloads of 250gr TSXs. My MK V 340 bests that by 250 fps (26" barrel).

quote:

Originally posted by Stonecreek:
The Mark V action is available in .257, .270, and 7mm Weatherby, all of which are similar in LOA to the .338 Win, so unless the Mark V for the .340 is modified in some way I can't see why the slightly shorter .338 Win wouldn't feed just fine.

But the greater question is why? If you simply want a Mark V in .338 Win then you can use any Mark V currently chambered for one of the above Weatherby calibers instead of having to use only a .340 Mark V.

BTW, I've owned both calibers in identical rifles. The .340 provided no significant advantage in velocity over the .338 and was more temperamental in the accuracy department. Despite only providing 50-75 fps more velocity, it kicked noticeably more with more muzzle blast (and remember, these were identical rifles, both with 24" barrels). The brass was also much more expensive. I happily kept the .338 and sent the .340 down the road.

My 340 gets an honest 100-125 FPS over my 338s. My 340 is a 24" and so are my 338s. My 340 do nearly 2900 with a 250. Is that an advantage? I don't think so but it does represent about max velo in a 24" 7 3/4 lbs rifle that I care to deal with. I would be perfectly happy with hunting with either one. There is a lot to like about the 338 however.

There hasn't been a time, in the past 40 years, that I haven't had a 338 WM in battery but I also built a 340 with a 26" Lilja barrel on the Rem action that shoots like it wants to be a varmint rifle. It's a fine killer of everything large and small!

The barrel length isn't objectionable for the ridge-line hunting that I do for elk. It just works!

Zeke

My 26" MKV 340 Wby gets 2970fps with factory 250gr. Not a 338 load within pressure limits within 100fps that I'm aware of. The 340 in a 26" is 200 to 250 fps more than the 338 in a 24".

quote:

BTW, I've owned both calibers in identical rifles. The .340 provided no significant advantage in velocity over the .338 and was more temperamental in the accuracy department. Despite only providing 50-75 fps more velocity, it kicked noticeably more with more muzzle blast (and remember, these were identical rifles, both with 24" barrels). The brass was also much more expensive. I happily kept the .338 and sent the .340 down the road.

Mine were not identical rifles, but in spite of the recoil, I went the other way and kept the .340 and said good bye to the.338. Course I also am not a fan of the .270 and .30-06 and they have killed plenty of critters over the decades. It boils down to Personal Choice.

I can't tolerate the 340 recoil and will be building a bull-barrel 338 around 10 pounds to keep the recoil in check. I find the 7.5# guns to be way too light in these calibers.

to each his own.

The trade off for shooting comfort is hiking and hunting discomfort with a heavier rifle.

The snappy jump of lighter 338's might be annoying but it is ultimately a mental thing since it doesn't really hurt anyone.

It really isn't the lessened recoil that is the reason to build a 9.5# .338. Another major reason is the ease of aiming stability. 2 pounds extra in a rifle makes a huge difference in how much that reticle likes to dance around at 300 yards.

I have been on the fence about having a 340 WBY put together, even bought some brass and a couple of proposed donor rifles. Just cannot convince myself it is worth the effort, yet. Much the same with the 375 WBY. But I do like the cartridges. As I also do the 338 Win, 375 Ruger, and 375 H&H.

-------------------------------------------------

quote:

Originally posted by smallfry:

quote:

Originally posted by Stonecreek:
The Mark V action is available in .257, .270, and 7mm Weatherby, all of which are similar in LOA to the .338 Win, so unless the Mark V for the .340 is modified in some way I can't see why the slightly shorter .338 Win wouldn't feed just fine.

But the greater question is why? If you simply want a Mark V in .338 Win then you can use any Mark V currently chambered for one of the above Weatherby calibers instead of having to use only a .340 Mark V.

BTW, I've owned both calibers in identical rifles. The .340 provided no significant advantage in velocity over the .338 and was more temperamental in the accuracy department. Despite only providing 50-75 fps more velocity, it kicked noticeably more with more muzzle blast (and remember, these were identical rifles, both with 24" barrels). The brass was also much more expensive. I happily kept the .338 and sent the .340 down the road.

My 340 gets an honest 100-125 FPS over my 338s. My 340 is a 24" and so are my 338s. My 340 do nearly 2900 with a 250. Is that an advantage? I don't think so but it does represent about max velo in a 24" 7 3/4 lbs rifle that I care to deal with. I would be perfectly happy with hunting with either one. There is a lot to like about the 338 however.

quote:

Originally posted by ldmay375:
I have been on the fence about having a 340 WBY put together, even bought some brass and a couple of proposed donor rifles. Just cannot convince myself it is worth the effort, yet. Much the same with the 375 WBY. But I do like the cartridges. As I also do the 338 Win, 375 Ruger, and 375 H&H.

-------------------------------------------------

quote:

Originally posted by smallfry:

quote:

Originally posted by Stonecreek:
The Mark V action is available in .257, .270, and 7mm Weatherby, all of which are similar in LOA to the .338 Win, so unless the Mark V for the .340 is modified in some way I can't see why the slightly shorter .338 Win wouldn't feed just fine.

But the greater question is why? If you simply want a Mark V in .338 Win then you can use any Mark V currently chambered for one of the above Weatherby calibers instead of having to use only a .340 Mark V.

BTW, I've owned both calibers in identical rifles. The .340 provided no significant advantage in velocity over the .338 and was more temperamental in the accuracy department. Despite only providing 50-75 fps more velocity, it kicked noticeably more with more muzzle blast (and remember, these were identical rifles, both with 24" barrels). The brass was also much more expensive. I happily kept the .338 and sent the .340 down the road.

My 340 gets an honest 100-125 FPS over my 338s. My 340 is a 24" and so are my 338s. My 340 do nearly 2900 with a 250. Is that an advantage? I don't think so but it does represent about max velo in a 24" 7 3/4 lbs rifle that I care to deal with. I would be perfectly happy with hunting with either one. There is a lot to like about the 338 however.

Do you own a 338 win mag? The 340 Wby is a great cartridge as far as I am concerned but so is the 338 wm. Many like the 338 WM because it works great in a 22" barrel. Ironicaly none of my 338s have had a 22" including the one I just bought. Brad said I should chop it to 22" but I chickened out and chopped it to 24 . No biggie I can always chop another 2" off. My 340 has a 24 inch and I absolutly fine with that length and generaly can't stand 26" barrels in bolts.

quote:

Originally posted by smallfry:

quote:

Originally posted by ldmay375:
I have been on the fence about having a 340 WBY put together, even bought some brass and a couple of proposed donor rifles. Just cannot convince myself it is worth the effort, yet. Much the same with the 375 WBY. But I do like the cartridges. As I also do the 338 Win, 375 Ruger, and 375 H&H.

-------------------------------------------------

quote:

Originally posted by smallfry:

quote:

Originally posted by Stonecreek:
The Mark V action is available in .257, .270, and 7mm Weatherby, all of which are similar in LOA to the .338 Win, so unless the Mark V for the .340 is modified in some way I can't see why the slightly shorter .338 Win wouldn't feed just fine.

But the greater question is why? If you simply want a Mark V in .338 Win then you can use any Mark V currently chambered for one of the above Weatherby calibers instead of having to use only a .340 Mark V.

BTW, I've owned both calibers in identical rifles. The .340 provided no significant advantage in velocity over the .338 and was more temperamental in the accuracy department. Despite only providing 50-75 fps more velocity, it kicked noticeably more with more muzzle blast (and remember, these were identical rifles, both with 24" barrels). The brass was also much more expensive. I happily kept the .338 and sent the .340 down the road.

My 340 gets an honest 100-125 FPS over my 338s. My 340 is a 24" and so are my 338s. My 340 do nearly 2900 with a 250. Is that an advantage? I don't think so but it does represent about max velo in a 24" 7 3/4 lbs rifle that I care to deal with. I would be perfectly happy with hunting with either one. There is a lot to like about the 338 however.

Do you own a 338 win mag? The 340 Wby is a great cartridge as far as I am concerned but so is the 338 wm. Many like the 338 WM because it works great in a 22" barrel. Ironicaly none of my 338s have had a 22" including the one I just bought. Brad said I should chop it to 22" but I chickened out and chopped it to 24 . No biggie I can always chop another 2" off. My 340 has a 24 inch and I absolutly fine with that length and generaly can't stand 26" barrels in bolts.

------------------------------------------------
I do own a couple of Ruger 338 Win mags in stainless and synthetic, and a blued/walnut M70 Super Grade all with 24" barrels. My favorite using 338 is a older Mark II in a Pacific Research stock. The contemplated 340 would be / or would have been a re-barrel of a 375 H&H M70 stainless Classic.

for the powder capacity of the 340 and for the action length of the H&H donor rifle you could do a 338 Ruger (.338 in a 375Ruger-based case) and be able to load LONG OAL rounds in a magazine. Just saying.

quote:

Originally posted by 416Tanzan:
for the powder capacity of the 340 and for the action length of the H&H donor rifle you could do a 338 Ruger (.338 in a 375Ruger-based case) and be able to load LONG OAL rounds in a magazine. Just saying.

Not the original poster here, but I do like the 375 Ruger case. What I like about it, is that it fits fine in the 338 Win proportion Mark II action. I have 375 & 416 Rugers in Mark II's.

IF, Ruger / Hornady would produce a 338 Ruger, and Ruger would put it a SS Hawkeye Mark II; I am sure I would have at least one. It appears Nosler will introduce their 338 before Ruger does (if ever).

I have a few 375 H&H's, love the round. But, with the 375 & 416 Rugers, I have pretty much convinced myself, if building a rifle, that I had rather have at least a 416 Bore in an H&H sized action. Not that I am going to purge my H&H's. I do have a M70 SS that is now a 416 Rem and think it is a near ideal match.

In my opinion the 300 WBY, 340 WBY, and 375 WBY are excellent rounds. I have a M70 SS factory form in 300WBY.

If I were building a heavy rifle in 338, and had an action set up for the WBY round, that is what I would build. Each to his/her own, everyone has their reasons that are important to them.

From the Barnes book, a bullet with .500 BC (roughly what the 225 TTSX is suppose to be): The 10mph wind drift difference at 400 yds, between 2700 & 3100 FPS is 2.2" and 335fps. The slower muzzle velocity of 2700 is still doing 2017 fps.

400yds would be a Very long shot for me, others may consider it close range. The 2700fps MV would work fine for me. Of course, so would the 3100 fps with a bullet that will penetrate on moose bone at less than 100yds, usually much less.

A rifle / cartridge combination preference is a personal thing. I am all for building what one wants. Though have obtained a couple that the idea sounded good at the time, but not so good after use; much like vehicles.

quote:

IF, Ruger / Hornady would produce a 338 Ruger, and Ruger would put it a SS Hawkeye Mark II; I am sure I would have at least one. It appears Nosler will introduce their 338 before Ruger does (if ever).

Me, too. Preferably the Ruger, since it would be half price of a Nosler rifle and the Ruger would have a nice claw extractor. But a push-feed is not a deal breaker for me in a little calibre like a .338".

quote:

I had rather have at least a 416 Bore in an H&H sized action.

Agree on this, too. However, I also want a .590" bolt face on an H&H-sized action, in other words, the 416Rigby, hand loaded, in order to maintain high BC bullets at 2800fps. Smaller actions than the H&H length can use smaller bolt faces, like .532-.535", and thus smaller actions under 40 cal.

However, my 500 Nyati is teaching me that H&H lengths are not needed in the larger bores. I don't want loads over 6000-7000 foot-pounds. So 2.65" is all the case length necessary.


The question comes down to the bullet(s) that one wants to shoot, and the velocities desired and willing to pay for in the sense of recoil and carrying weight of the rifle. Out to 400 yards a BC of .400-.500 seems sufficient.
In .416 I am contemplating downsizing in the next ten years to a 416 Ruger capacity (which is functionally equivalent to the 416Remington.) That would require lighter bullets than the 350TTSX to maintain speed, or else getting used to 2550-2600fps. Or maybe I'll just borrow my wife's little 375 Ruger with 250TTSX at 2850fps.

My post just above leads me to the following recommendations:

For hunting out to 400 yards, the 338WinMag is really excellent and all that one needs, although a 338 Ruger or 338 Nosler, should they be available in light-medium weight commercial offerings would be slightly nicer.

For hunting over 400 yards an H&H length action would be useful and should have its boltface enlarged to .590", with rails minutely widened. (This is done on a controlled-feed rather than a push-feed.) The .338" bore should be reamed for the 338 Lapua , allowing use of the excellent Lapua brass and guaranteeing pretty good caliber demand because of the military use of the Lapua. The 338 Norma could be considered, but only if very long bullets were going to be used. Such extra-long bullets are not normally used for hunting at shorter ranges, so the 338 Norma would become a long-range only rifle while the 338 Lapua could be loaded with more all around bullets.

If the donor rifle is an H&H length .532" bolt-face push feed, then a 338 RUM or 338 Edge would the choice for over-400 yard hunting, though the first mention above, 338WM (and 338 Ruger, 338 Nosler, when/where available) remain the run away best choices for under 400 yard hunting.
That's how I see the sliding parameters playing out.

PS: Just saw the second note about recoil in a 7.5# rifle. By all means, get a 338 WinMag ready-made. The Tikka, with scope, will end up 7.5 to 8#. But they are sweet little rifles in 338, I've had two, both with limbsaver pads. You might want to try the 338WinMag in Ruger African. It has an extra pound of weight and even has a muzzle brake for when everyone has hearing protection on.

quote:

Originally posted by ar corey:
If I buy a 340 in a Mark V, can I spin a 338 Win mag barrel on it? Will it still feed properly?

Probably. I came across a small issue when I re-barrelled a .300 Weatherby to .300 Win Mag which the same combination of long/short you are contemplating. There are a couple of small nubs at the top-front of the mag box that serve to nudge the longer case toward center on the forward stroke. On the shorter cartridge they pushed it right across and caused the bullet tips to hit on the opposite side of the chamber. A few pulls with a flat file removed them. I did it in stages, with a bit of cut and try but in the end I could have just removed them in one pass. Function is perfect now, and a long mag box is practically its own reward.

Thanks Dog!

Maybe I should look into buying a 257 Weatherby caliber instead of the 340 as suggested here. 2.545" of case length is close enough to 2.5" that it shouldn't make any difference. I will be shooting the Barnes TTSX 185 exclusively in the 338 Win Mag. so I am not concerned about magazine well depth.

338 LM requires a really big action. A 340 Bee works on any H&H length. The performance is essentially the same. One of the non double radius designs may be "better" but then its a wildcat. 340 Wby would by my first choice.

Lead,

I am not chambering for the Lapua. I am chambering only for the 338 Win. Mag. so a 257 Weatherby action should be perfect!

quote:

Originally posted by ar corey:
Lead,

I am not chambering for the Lapua. I am chambering only for the 338 Win. Mag. so a 257 Weatherby action should be perfect!

Sorry was a bit of a highjack - my reply was in response to 416Tanzan.

338 Win Mad and 340 Wby are both great calibres.

I've owned a couple of .338 Win Mags, the first a Sako Fullstock Carbine in a 20" barrel. Factory velocity of 2660 for 250s was it's absolute limit from best handloads. About 2700 from 225s.

The second was a new 26" Browning A-Bolt SS that delivered a 250 at 2840 fps from a book load of RL-19. After about a month of playing with it, I had it reamed to .340 WBY and bought a .375 H&H clip that attached to the floorplate. An honest avg. vel. from the 250 NP over a period of about ten years was 2997 fps. A bull moose was shot with that load. I fired about 1000 through it and then it was sold. Recoil wasn't a factor. The difference in MV from being a factory 26" in .338 Win Mag at 2840 to about 3000 as a 340 was 160 fps. I used RL-22 exclusively for the 250 NP.

The rifle only weighed about 8.75 lbs with scope, ammo and sling. A 26" barrel is best in my view for the .340 in particular, but I've had a 26" .300 Win Mag that was also far better than my 24's. 3200 fps from 180s and 3000 from 200s.
It was an identical rifle to the .340 in a Browning A-Bolt SS (LH). The .340 would shoot MOA and the .300 1/2 MOA.

Bob

www.bigbores.ca

quote:

Originally posted by .458 Only:
I've owned a couple of .338 Win Mags, the first a Sako Fullstock Carbine in a 20" barrel. Factory velocity of 2660 for 250s was it's absolute limit from best handloads. About 2700 from 225s.

The second was a new 26" Browning A-Bolt SS that delivered a 250 at 2840 fps from a book load of RL-19. After about a month of playing with it, I had it reamed to .340 WBY and bought a .375 H&H clip that attached to the floorplate. An honest avg. vel. from the 250 NP over a period of about ten years was 2997 fps. A bull moose was shot with that load. I fired about 1000 through it and then it was sold. Recoil wasn't a factor. The difference in MV from being a factory 26" in .338 Win Mag at 2840 to about 3000 as a 340 was 160 fps. I used RL-22 exclusively for the 250 NP.

The rifle only weighed about 8.75 lbs with scope, ammo and sling. A 26" barrel is best in my view for the .340 in particular, but I've had a 26" .300 Win Mag that was also far better than my 24's. 3200 fps from 180s and 3000 from 200s.
It was an identical rifle to the .340 in a Browning A-Bolt SS (LH). The .340 would shoot MOA and the .300 1/2 MOA.

Bob

www.bigbores.ca

What velocity did that 338 "book load" reflect in the book? I've never seen a manual getting 2850 fps with a 250gr in a 338, but I've not read every manual out there. That said 2 inches could add 60 plus fps. I need to read some data with RL19. I tend to focus on data close to our local propellants.

I don't doubt you did get the results but if data gives you more velocity than the manual then your system and combination of barrel chamber components etc is likely "tighter" and pressure likely higher so I just wanted an idea as to what was theoretically expected with the load. Either way they are both awesome calibres and I own both. I have a Kimer 26 inch 338 coming now as well so in theory with S365 a 250gr at over 2800fps is possible. That said our S365 seems to be one of the best propellants for the 338 as per the Somchem book.

quote:

Either way they are both awesome calibres and I own both. I have a Kimer 26 inch 338 coming now as well so in theory with S365 a 250gr at over 2800fps is possible. That said our S365 seems to be one of the best propellants for the 338 as per the Somchem book.

I've got a 338 WinMag about to be released from its Calif waiting period. It is a Ruger Hawkeye and will be bedded and have loads tested for a hunt this Fall. Maybe a 200 grain CEB MTH at 3000-3050 fps, if it shoots well.

For the future, I would consider a rechambering to a 338/375Ruger if the chambering and reamer were available and relatively easy. That would be equivalent to the 340 Weatherby capacity though in a standard length cartridge/magazine. But the 338 Win Mag is great as it is, and if this rifle shoots well it will stay as it is.

quote:

Originally posted by AFRICAN LEADWOOD:

quote:

Originally posted by .458 Only:
I've owned a couple of .338 Win Mags, the first a Sako Fullstock Carbine in a 20" barrel. Factory velocity of 2660 for 250s was it's absolute limit from best handloads. About 2700 from 225s.



The second was a new 26" Browning A-Bolt SS that delivered a 250 at 2840 fps from a book load of RL-19. After about a month of playing with it, I had it reamed to .340 WBY and bought a .375 H&H clip that attached to the floorplate. An honest avg. vel. from the 250 NP over a period of about ten years was 2997 fps. A bull moose was shot with that load. I fired about 1000 through it and then it was sold. Recoil wasn't a factor. The difference in MV from being a factory 26" in .338 Win Mag at 2840 to about 3000 as a 340 was 160 fps. I used RL-22 exclusively for the 250 NP.

The rifle only weighed about 8.75 lbs with scope, ammo and sling. A 26" barrel is best in my view for the .340 in particular, but I've had a 26" .300 Win Mag that was also far better than my 24's. 3200 fps from 180s and 3000 from 200s.
It was an identical rifle to the .340 in a Browning A-Bolt SS (LH). The .340 would shoot MOA and the .300 1/2 MOA.

Bob

www.bigbores.ca

What velocity did that 338 "book load" reflect in the book? I've never seen a manual getting 2850 fps with a 250gr in a 338, but I've not read every manual out there. That said 2 inches could add 60 plus fps. I need to read some data with RL19. I tend to focus on data close to our local propellants.

I don't doubt you did get the results but if data gives you more velocity than the manual then your system and combination of barrel chamber components etc is likely "tighter" and pressure likely higher so I just wanted an idea as to what was theoretically expected with the load. Either way they are both awesome calibres and I own both. I have a Kimer 26 inch 338 coming now as well so in theory with S365 a 250gr at over 2800fps is possible. That said our S365 seems to be one of the best propellants for the 338 as per the Somchem book.

My Kimber .338 Win will do 2850 fps with listed loads of H4350. 26" barrel.

Just take 5 grains of powder out, it'll be a .338wm , casings will last forever at those lower pressures, why spend all the cash for no reason...then you can buy another toy to tinker with.

If it shoots at the lower level, sure. Magnums aren't exactly famous for running right with light loads.

You may still want to use the longer box rather than a std length box. I have had issues with COAL using Barnes TSX and running out of room.

Long mag boxes on standard length cartridges are practically their own reward.

quote:

Originally posted by FMC:
You may still want to use the longer box rather than a std length box. I have had issues with COAL using Barnes TSX and running out of room.

Thanks FMC and Dogleg!

I have enough problems with blood shot shoulders with a 338, the last thing I need is more velocity..My .338 is perfect for 350 yards but still destroys too much meat IMO. Its a balance between trajectory, killing power and meat destruction..The .338 Win is about as close as you can get to performing to that balance IMO..It ain't perfect but I'll have to do.