There are some mainstay cartridges that have established their consistency in the long range arena..308, 300 Win Mag, .338 Lapua.
Has the .300 Rem Ultra Mag established itsels as a consistent, accurate round? I know the ballistics are impressive, but........
What y'all think?
For a long rang target gun, I am trying to decide between the .300 RUM w/ 220 gr. bullets or the .338 Lapua.
Have a look at pages 618 & 619 of the 5th edition Sierra manual for some idea of 300RUMs accuracy, they show a little picture of Chris Lauck after a hit on a 11"x18" target at 1800yds using 190SMKs and John Buhay after shooting a perfect 100 with a group size of 5.377" using 200SMKs in 1000yd light gun class.
To me this demonstrates the accuracy potential of the 300RUM, although some will tell you that it is a well put together rifle that releases that potential and they are of course right, but it just goes to show what can be done.
When you step up to 338 Lapua things start to become a bit more specialized and more expensive but i'm not saying dont go there. For easy availability of guns and components, dies etc,(and less recoil) i would go for the 300RUM.
PS. Dont rule out the 338RUM, ballisticly equal to the 338 Lapua.
I have developed loads for at least a dozen 300 Ultra mags and have never not had them shoot 1/2-5/8" groups at 100 yards with RL 25 and 180 grain B tips or Accubonds. It can be a very accurate round given that the rifle is assembled properly. That being said, I would still rather have a .338 Ultra mag instead because of the benefit of better barrel life, heavier bullets available, and better downrange thump! A .300 win mag gives up very little in real world performance to the 300 ultra, and does so with 20 grains less powder, better barrel life, less barrel heat, less recoil, and also has better brass available.
Try the 300RUM necked to .338 I know of seven or so of these that really perform.And while the 300 win is a wonderful round and the .338 win is a good round (had both)
check the ballistics on a 300gr SMK going 3000fps, lets say the energy level or retained velocity and you can draw your own conclusions!I'd ask Kirby about his 7mm Allen mag, I've ran the numbers on it and it was very impressive.
Teh 300 RUM is a fine round for extreme range accuracy if as said the rifle is built properly. I would also add that I personally feel that the 300 RUM is far better served with a 200 gr or heavier pill then the lighter bullets. That is not to say the 180 gr bullets will not perform as they obviously will, in fact I used the 180 gr BST in my 300 RUM exclusively.
Still, from a ballistic and efficency standpoint, the 100 gr case capacity of the RUM will perform better with a 200 gr bullet or heavier.
I would also agree that the 338 has a couple advantages over the 300. First being barrel life and the second being on game performance as far as frontal area is concerned.
The 338-300 RUM or 338 Edge(Shawn C.s great round) are top performers that will match or slightly outperform the Lapua. Brass may not come out of the box as consistant but it can be made that way relatively easily. Serious round which I would say is basically on par with the 338 Lapua Imp.
While my 7mm Allen Mag will certainly offer ballistic performance higher then any round listed in this conversation and by a fair margin, it should be known that it is designed, just as the other Allen Mags as strictly a big game round for use at extreme range.
Barrel life will not be dramatically less then the likes of the 7mm RUM or 7.21 Firebird, especially with the 3 groove Lilja barrels and use of Ball powders but it will still be limited to the 1500 round range for extreme range big game hunting purposes.
Just wanted to make that point that it is not designed for use as a long range target round. Not that it would not perform amazingly well but high volume shooting is not where this round will excell. Where it is designed to be used is for the big game hunter wanting legit +1500 yard performance in a rifle that does not need to be 25 lbs in weight.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
I've just begun working a load for a .300 RUM with 210gr JLKs and CR 216s with RL-25 and H-1000. Punching 3/8" at 100 at around 3250 fps. Not too bad for a hunting rifle. Thought about a .338 Lap, much better brass but the bullet selection is better in the .30 cal. You must decide what you want to do with it and how fast you want to go. If you want a bench gun, go with a 6mm something, if you want a 2000yd shooter, do like the Armed Forces; 50BMG. I shoot a friends .338 RUM in a SSF Sendero on occasion. Hard hitting rifle with X bullets, but won't do nothing the .300 can't do at realistic hunting distances. There's also some pretty good Federal brass in the .300 RUM available.