i finally found some one to build me a long range rig for me in my area but i cant pick a cartridge i was looking at 338/378 W 338 L or a 338 rum he was showing me the 408 cheytac round but i think the cost would be little high
While on paper the big 408 is dominant in ballistic performance, sadly there are few bullets that allow this huge round to perform anywhere near its potential.
I personally feel that until a quality lead core bullet is offered for this bullet, accuracy and consistancy problems will hurt its future.
I personally like the other three rounds for long and extreme range shooting and hunting. There are few rounds that will stand with a big 338 round driving a 300 gr VLD or ULD to velocities in the 2600 to 3000 fps range.
If the three, the 338 RUM is certainly the best bang for the buck. There are factory rifles available and brass is very low price compared to the other two. The 338 will get the 300 gr bullets to very near 2600 fps which is plenty of velocity for good extreme range performance.
The 338 Lapua, while a great performer has kind of been ballistically matched by the 338 RUM. It is true the 338 Lapua has a slight velocity advantage but when you look at the cost of brass and it really is not that much better then the 338 RUM in a quality rifle.
Still the Lapua is designed for long range shooting and it is an exceptionally accurate round.
My pick of the three would be the 338-378 of you wanted a factory offered round. It will give roughly 200 fps advantage over the 338 Lapua in all barrel lengths and brass is very good quality at a decent price. It is much more costly then the RUM but being made by Norma it is very good quality brass.
If your looking for something in the wildcat world, I would highly recommend wither the 338 EDGE or the 338 Kahn.
The Edge was designed by Shawn Carlock and has performed amazingly well from the data I have seen. It is built on a full length 300 RUM case necked up to 338(a better design then the shorter 338 RUM)
This round is the full equal to the Lapua and can be used in any true long action rifle even in repeating form depending on throat design and bullet used.
The 338 Kahn is a 338-378 Wby with the shoulder improved to a 35 degree conventional shoulder and moved forward slightly to allow the 338-378 parent case to chamber and fire without any modification.
The 338 Kahn will hit 3100 fps in a 34" barrel and well over 3000 fps with the 300 gr bullets in a 32" barrel.
My Kahn is capable of 1/5 moa at 500 yards if I do my part in good conditions driving the 300 gr Wildcat ULD to 3070 fps which is a relatively mild load in a short throated chamber.
No matter the round, if you get a 300 gr ULD or VLD to at least 2600 fps in a match quality rifle, you will get impressive down range performance.