Re: Converting a .338 RUM to edge
300 RUM and 338RUM brass are the same price. Nobody was working with the 338-300 RUM before me unless it was remington developement. Maybe some about the same time but nobody earlier that I am aware of. I worked with it hard from late 1998 till 2001 when the 338 RUM came out. I tested both extensvely on the range at my shop. Few would know both cartridges as well or better than me. I would venture to say there is more hands on experience on this site with these cartridges than anywhere else. Several guys have quite a bit of experience with these here. They are both very good long range big game cartridges. Either will do anything the other will. Just personal prefference.
If you tested 100 barrels in each the 338-300 rum should average out with a slight velocity advantage with slightly more case capacity. But they both occupy close to the same numbers and the best accuracy in either could be faster than the next guy with either. In other words one guy might get 2750 fps best accuracy with one and 2850 fps with the other. The next guy may get the exact opposite. They are just to close to call. I can tell you from quite a bit of experience with both either will do anything the other will in a hunting situation. The 338's take quite a bit of powder to make a slight velocity difference between cartridges. These two RUM's are about 125 fps faster than the 340 Weatherby and it takes about 10 grains more powder to do it. The 338-378 wby is about 200 fps faster than these two RUM's and it takes about 20 more grains of powder to do that. Since the best accuracy with these two are within 1-2 grains of powder how much velocity difference will there be?
What part of Alabama are you from? Sniper2 on here is in Centre and had one of the first 338-300 Rum's ever built at my shop. He can tell you about it if you are near there. They are excellent rifles.
Just to add to that the new 338 SIN Sinarms is working on is about halfway between the 340 wby and the RUM's in powder capacity but in initial testing it looks like he will get at least high 2700's with the 300 grainers. There is just not much difference in 338's unless you get a bunch more powder involved.
Predictions are difficult, especially when they involve the future
Last edited by Long Time Long Ranger; 04-27-2011 at 11:46 AM.