Dr. Tad Hussein Winslow
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Compare and contrast; pros & cons - go! 
.338 Lapua vs. .338 RUM vs. .338-378 Wby
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Zak Smith
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I've tested/owned all but the Wby. .338RUM has basically identical ballistic performance to .338LM. The Wby has about 25% more case capacity, but this means you need to use super-slow 50BMG-style powders to take advantage of it. You might get 100-150 fps more with the 300gr bullets with the Wby over the Lapua or RUM.
Dr. Tad Hussein Winslow
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Thanks!
338 lapua = mimics a max pressure/hot 338 winchester, a very over hyped waste of money.
338 Rum is where the .338 gets interesting..as far as ballistics go and its the cheapest 338 hot rod to shoot..
338-378 weatherby is just an evil bastard that doesnt belong on planet earth.. theres actually some loadings with H1000 or RL25 that put the 300gr smk at 2950
338 Rum is where the .338 gets interesting..as far as ballistics go and its the cheapest 338 hot rod to shoot..
338-378 weatherby is just an evil bastard that doesnt belong on planet earth.. theres actually some loadings with H1000 or RL25 that put the 300gr smk at 2950
gvnwst
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If you like that, check out the .338 excalibur, pull out your "Cartridges of the World" and check it out. Something like 200fps over the .338/378 with 250gr bullets.
Indeed would be beautiful however the cost of such a rifle.. vs a accumark weatherby im sure would be thousands more.. and is far as reloading goes.. im still novice.. so forming my own cases then fireforming would be iffy.
Down the road.. might be a wise investment if I wanna take shots on brownbear past 1000 yards hehe.
Zak Smith
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338LM and 338RUM have within 0.4gr of the same water capacity with a 300gr SMK seated to spec length (3.6" and 3.68"). Their ballistic performance is essentially identical. The 338LM does it with a fatter but slightly shorter case. It also has a less steep neck angle which aids feeding.
............... Larger version of above photo.
The .338 Win Mag you refer to has 27% less powder capacity than either (again with a 300gr SMK seated). It has no chance of ever meeting a standard or max load in 338LM or RUM.
gvnwst
Member
Can't remember where, but one can buy pre made brass, you actually can't fireform it out of any cartridge i know of. It is the same base size as the .338/378, so it would be as simple as a rebarreling/rechambering. Nice to know it is a bit closer, eh?
Zak Smith
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The European military load is the Lapua 250gr Lock-Base at 2950 fps.
http://www.lapua.com/index.php?id=888
I don't know where you got your idea about a "handicap in performance."
article | Military .338 Lapua Magnum Rifles: the Sako TRG-42 and the AI-AWSM
http://www.lapua.com/index.php?id=888
I don't know where you got your idea about a "handicap in performance."
article | Military .338 Lapua Magnum Rifles: the Sako TRG-42 and the AI-AWSM
Albert A Rasch
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Nice one Zac!
I have only fired the .338 Lapua Magnum in the Desert Arms SRS (Which BTW I still haven't reviewed...) I thought it was a very consistent performer. I don't know much about the RUM, and I'm not sure if anyone would care to use one hunting after shooting it a couple of times.
I shot the DA SRS off a bench and bipod so it isn't fair to comment about the recoil. It was heavy but not sharp, and very tolerable. Accuracy was phenomenal with match Lapua ammo.
Regards,
Albert A Rasch
The Rasch Outdoor Chronicles
I have only fired the .338 Lapua Magnum in the Desert Arms SRS (Which BTW I still haven't reviewed...) I thought it was a very consistent performer. I don't know much about the RUM, and I'm not sure if anyone would care to use one hunting after shooting it a couple of times.
I shot the DA SRS off a bench and bipod so it isn't fair to comment about the recoil. It was heavy but not sharp, and very tolerable. Accuracy was phenomenal with match Lapua ammo.
Regards,
Albert A Rasch
The Rasch Outdoor Chronicles
Strongbad
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From a cost perspective, the RUM is the best of the 3. The Lapua and Wby both have super expensive brass, and it's only made by one or two folks.
Quality-wise, I believe that the Lapua has the best brass of the 3.
The Wby offers a performance advantage over the other two, but I don't believe that the cartridge is as accurate as the Lapua, and I do have a basis for judgement, as I own one. I have a custom built 338/378 with a Shilen barrel, it's 2nd barrel actually. I put about 2000 rds through the first.
IMHO the trick to getting the most out of all 3 is a custom barrel that is longer than 26". How much longer is up to you, but it wouldn't hurt you to have one up to 34" and possibly beyond. Mine is 29", and with the right powders can push the 300 gr. Matchkings to just shy of 3000 fps. and the 250's to 3250. Figure on 50-75 fps average for every extra inch of barrel that you add. The slower the powder the better. RL25, 50BMG, AA8700, H-870, etc.
Quality-wise, I believe that the Lapua has the best brass of the 3.
The Wby offers a performance advantage over the other two, but I don't believe that the cartridge is as accurate as the Lapua, and I do have a basis for judgement, as I own one. I have a custom built 338/378 with a Shilen barrel, it's 2nd barrel actually. I put about 2000 rds through the first.
IMHO the trick to getting the most out of all 3 is a custom barrel that is longer than 26". How much longer is up to you, but it wouldn't hurt you to have one up to 34" and possibly beyond. Mine is 29", and with the right powders can push the 300 gr. Matchkings to just shy of 3000 fps. and the 250's to 3250. Figure on 50-75 fps average for every extra inch of barrel that you add. The slower the powder the better. RL25, 50BMG, AA8700, H-870, etc.
Buckskinner
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how does the .340 wby mag compare to the .338 LM and .338 RUM?
gvnwst
Member
That artical is great. In many ways for me, it is actually the artical that got me into shooting! Before i barely even shot 5 rounds a year, now....can't afford all the ammo! Thanks Zak. But since then, i have wanted a AI AWSM, and can't afford it!
My book (cartridges of the world) shows wby factory loads running a 250gr SP at 2,980fps.
But since then, i have wanted a AI AWSM, and can't afford it!My book (cartridges of the world) shows wby factory loads running a 250gr SP at 2,980fps.
Zak Smith
Member
I had a demo rifle in 338 RUM for a while, and my 338 is the Lapua (AI-AWSM). I have friends who have built 338RUMs to meet budget, and several who went the Lapua route. Recoil between the cartridges will be the same. However, felt recoil is determined primarily by the quality of the muzzle brake (and secondly rifle/shooter "fit"). For example, the TRG-42 is quite a bit lighter than the AI, but recoil is similar because the brake is very effective.
This is an interesting point. Only Remington makes 338RUM brass - as far as I know. However, Lapua, Hornady, and Norma make 338 Lapua brass. The Remington brass is 1/3 - 1/2 the cost of Lapua, but, well, you're stuck with Remington brass.
Strongbad
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lol Yup. One thing I also forgot to mention was bolt face size. The Lapua is based roughly on a 416 Rigby which was also the basis for the 378 based Wby rounds. It takes a long action and a big boltface... a Rem 700 wont do, whereas the RUM with it's rebated rim will fit in regular long action with a standard magnum bolt face.
I believe that Nosler is now making 300 RUM which you could neck up, but shoving the shoulder back would be another matter.
Zak Smith
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berettashotgun
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The UM cases have a rebated rim?
Your kidding me, I'm not seeing much of a 284win style rebated rim here.
I'd get the Ultramag in a 7mm and get a 1:8.5 twist 29-32"barrel. Shoot big bullets, buy new barrel in 500 or so rounds. Good times.
BTW, never have shot my 338RUM, but know for a fact the hinged floorplate on my 700BDL 375RUM didn't stand up to recoil after 34 rounds with a brake. Latch spring wasn't as strong as the recoil and kept flopping open.
Your kidding me, I'm not seeing much of a 284win style rebated rim here.
I'd get the Ultramag in a 7mm and get a 1:8.5 twist 29-32"barrel. Shoot big bullets, buy new barrel in 500 or so rounds. Good times.
BTW, never have shot my 338RUM, but know for a fact the hinged floorplate on my 700BDL 375RUM didn't stand up to recoil after 34 rounds with a brake. Latch spring wasn't as strong as the recoil and kept flopping open.
Zak Smith
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I have a 338RUM case right here. Case head diameter is 0.528, web is 0.548.
Sgt. Brooks
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Well as far as balistic you can get more out of the wby but for accuracy on the long shots and consistancy i have shot all three and i say that the 338 lapua mag is the best. I love it but it is pricey. especially when you start getting into match grade ammo thats solid and turnd on a lathe. but hey to me its worth it. being able to pull the trigger lite the cigerett and then look back into the scope to watch the bullet hit is awesome lol. As far as im concerned if you want to put 100's to 1000's of rounds down range or at something get a cheaper gun or a semi auto or full auto lol. its ment to be sighted in and shot a few times or practice and then comp. or the real reason to kill over seas. bottem line if you want to get out there and touch something. dont get it if you want to get out there and blow it away with accuracy and consistancy this is your round but make sure the barrel is long and if your using a solid round turned on a lathe its usually lighter so you might just want to make sure you got enough powder in there.
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