338-8mm Rem Mag
- Thread starter Firecat
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cedarswamp1
Active Member
Gives up too much to the non belted 338 magnums to make it worth the hassle IMHO.
coonhunter
Active Member
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- Dec 23, 2007
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I have no experience with one but if you are looking for performance info the 340 weatherby should be really close.
Long Time Long Ranger
Well-Known Member
Has been done quite a bit since the late 70's. What you get is a 340 wby with cheap remington brass. It is a very good cartridge well capable of 1000 yard hunting. It shoots on average about 100-150 fps slower than the 338-300 ultramag or edge, 338 RUM and 338 Lapua.
liltank
Well-Known Member
How much do you want to pay for brass? They all shoot relatively the same. Lapua gives you the best brass. The Edge is proving quite deadly and relatively the same price as a rum or lapua. So its a toss up.
Tank
Which would be the fastest in order? And what would the velocity difference be? I know that not all decisions need to be based on speed, However it is nice to know. If you were doing a new build of these three calibers which would you choose and why?
Long Time Long Ranger
Well-Known Member
Since the ultramag case came out the 338-8mm rem mag and 340 wby are not as popular. If you have a donor standard magnum action then do the ultramag case. If you are doing a custom action then there are many more choices. I have both the 338-300 ultramag and the 338 RUM. I hunt often with my 338 RUM and the two 338-300 ultras have pretty much sat in the rack for ten years. Performance is the same and either will do anything the other will do. But I can buy dies, brass, etc over the counter cheap for my 338 RUM. No necking up and fireforming brass so the 338 RUM always went hunting since it was much easier to load for.
I also have two 338 Lapuas and again the performance is the same as the other two but brass is more expensive and you must open up the bolt face since it is larger. My wife just shot a monster mulie with a Lapua at 516 yards. You could work up accuracy loads with all three and carry to the range. Without looking at the stamp on the barrel you would have no idea which one you were shooting and neither would the animal. Your choice. Bottom line you are comparing three cartridges that do the exact same thing.
I also have two 338 Lapuas and again the performance is the same as the other two but brass is more expensive and you must open up the bolt face since it is larger. My wife just shot a monster mulie with a Lapua at 516 yards. You could work up accuracy loads with all three and carry to the range. Without looking at the stamp on the barrel you would have no idea which one you were shooting and neither would the animal. Your choice. Bottom line you are comparing three cartridges that do the exact same thing.
liltank
Well-Known Member
The RUM and Edge are going to be practically ballistic twins. The Edge will edge out the RUM by about 15 to 20 fps and again the Lapua will be the best performer due to the better casing. It will only gain you maybe another 15 to 30 fps over the first two, but that has many variables. If I were to build a big bore, I would go with the RUM due to costs. It will be cheaper to get started with the RUM and shoot practically the same as the other two. The Edge is still considered a wildcat due to no one making factory ammo for it. Both the RUM and Lapua you can find in a store. Dies will be readily available for both the RUM and Lapua.
So with that said, if you want a big performer, then step it up to the 338LM AI. Then you will be pushing the 300SMK or Berger north of 2950fps. Also the 338-378 Weatherby will romp on a 300SMK or Berger pretty good too. You can use factory ammo in a pinch, and load the AI version at your leisure.
Tank
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Guys, this has been great for me to get my head around. I appreciate your input. I was under the impression for a long time that there was a greater margin of performance between the three that we have talked about. If the difference in performance is less than 100 fps or 120 for that matter than it makes sense to go with most economical route for me. Seems to me that would be the RUM. I seriously doubt that an elk at 800 yards is going to know the difference.
liltank
Well-Known Member
Yep your right. They won't know a difference out to about 1400yrds. Loaded with a 300grn bullet, won't be an issue. There are some really nice 225 grn bullets that will get you that far and more. Good luck on your build. Hope to see pics when your done.
Tank
Long Time Long Ranger
Well-Known Member
Firecat, Before I retired I had a shop and a 1000 yard range outside the door of it. I built the 338-300 ultramag from late 98 until 2001 when the 338 RUM came out. I also did the Lapua and tested several versions of improving it. The improved Lapua is the best of this bunch in my opinion if you want a wildcat and will get you another 100 fps. Velocity wise, averaging many rifles, if you were splitting hairs there would be a slight gain in velocity from the 338 RUM to the 338-300 RUM to the 338 Lapua. I think the brass loaded to higher pressures may be what gives the lapua a slight advantage. We are talking maybe 20 fps between each one. But this would be taking the average of 10 rifles in each cartridge.
For one guy, getting one rifle built the accuracy load in either of the three may outperform the other. In other words it depends on your individual barrel and rifle. Some barrels are fast and some are slower. You may get a 338 Lapua that does best at 2725 fps a 338-300 ultra or edge that does best at 2740 fps and a 338 RUM that does best at 2850 fps. Interchange any of them into any of these velocities. Best load in any of them could be anywhere between 2725 fps and 2850 fps with a 30" barrel(or a fast barrel even faster). But that is the range for all three. That is why I say all three are the exact same thing. Accuracy wise they are all three extremely accurate and have not seen any of the three with an advantage there. I shot all three head to head many rounds on my range.
Again, if you are doing a custom rifles there are others that will outperform these by 200-300 fps. The Lapua improved can get near 3000 fps and the improved 338-378 wby case and Excalibur can hit 3100 fps. All are accurate.
For one guy, getting one rifle built the accuracy load in either of the three may outperform the other. In other words it depends on your individual barrel and rifle. Some barrels are fast and some are slower. You may get a 338 Lapua that does best at 2725 fps a 338-300 ultra or edge that does best at 2740 fps and a 338 RUM that does best at 2850 fps. Interchange any of them into any of these velocities. Best load in any of them could be anywhere between 2725 fps and 2850 fps with a 30" barrel(or a fast barrel even faster). But that is the range for all three. That is why I say all three are the exact same thing. Accuracy wise they are all three extremely accurate and have not seen any of the three with an advantage there. I shot all three head to head many rounds on my range.
Again, if you are doing a custom rifles there are others that will outperform these by 200-300 fps. The Lapua improved can get near 3000 fps and the improved 338-378 wby case and Excalibur can hit 3100 fps. All are accurate.
LTLR thank you for your advice. I am Considering doing a build. I would consider any of the three that we have talked about. The Lapua improved is intriguing. Its kinda nice to be able to talk to those who are willing to share their thoughts and experiences so freely. I appreciate it.
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MudRunner2005
Well-Known Member
Any input on this cartridge in a 24-25" factory Remington stainless sporter barrel?
It's almost a waste to let my .338 barrel to go rust, and I love my 7mm STW, and this cartridge uses the same basic brass. So it has very recently piqued my curiousity...
It's almost a waste to let my .338 barrel to go rust, and I love my 7mm STW, and this cartridge uses the same basic brass. So it has very recently piqued my curiousity...
