338 rum (improved???)

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600BP

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A quick question for those in the know. I have a 338 RUM that I would like to have re-built. Possibly just having a 30 inch barrel put on, or changing to a 338 Edge (or Edge +P:D). My question is: has anyone tried to change the shoulder on the original 338 RUM to get better ballistics (338 RUM Improved?). If so, was it a successful or didn't it give any better performance than the original round. Just being curious before I have the gun re-built.lightbulb
 
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from my understanding the .338 RUM cannot be improved very much. Niether can the edge. Not that it cant be dont, it just doesnt help much. If your gonna screw a new tube on your rifle and your thinking a 30" i would go for the EDGE. If you have a big action (WBY or custom) I would go Lapua Improved. The +P sound promising, but dont hold your breath.
 
You just can't gain enough powder capacity with improving the ultramag case to make it worthwhile. With 338 it takes quite a bit of powder to make a noticable difference. That is why the 338 RUM, 338-300 RUM or edge or whatever, and 338 lapua all shoot exactly the same. The difference between barrels in either one determines whether your accuracy load will be in the 2700's or 2800's fps with the 300 smk and not which of these three you choose. The lapua case has more room for improvement and you can gain some there and jump into the 2900's fps with the 300 grain. Then the huge 378 wby case improved and the 416 rigby imp case can get you over 3100 fps. To get the extra velocities 3-5 grains more powder in an ultramag case just isn't going to matter. 15-20 more grains in the big cases will give you a little extra velocity. The Excalibur which is about the same thing as a 416 rigby improved is about the best you can do with easy to get brass for your mk 5 action. They can get over 3100 fps with the 300 smk in a 30 inch barrel. It is a standard cartridge which makes it much easier.
 
338-300 RUM is just that. A 300 RUM necked to 338. It is what we wildcatted from 1998-2001 until the 338 RUM came out. They shortenned the 338 RUM case slightly so it would feed better in the 700 actions with the bullets seated properly. Changes the capacity slightly but performance is the same.
 
Oh, that clears up a lot for me. I was also thimking the edge was something totally different too. I was really close at one point on getting the 338RUM but decided that "what can I not do with one of my 300RUMs that I need a 338 for".:) I guess the only reason I would really concider getting a 338RUM is if I lived where the elk and moose roamed with an occasional grizz. But just for added insurance tho. But I will never feel under gunned with my 300RUM.:)
 
338 Excalibur....the A Square right? I haven't heard or read anything about this round recently. Truthfully I don't even know anyone who has any working knowledge of this round. Is it as accurate at the majority of the 33's or not so much. I don't mind burning the powder as long as the results are what I hope for. Anybody?
 
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