Trueblue,
There is always some type of ballance we need to work with on long range rifles that are intended to be somewhat portable.
The nice thing about the 338 bore is that it is not dependant on barrel length to produce good velocity numbers. In fact from 26" out to 30", a chambering like the 338 Lapua Improved will gain 10-12 fps per inch and thats it!!! Past 30" it will drop to around 7-10 fps per inch depending on barrel. Simply not enough to worry about.
With lighter rifles, you need to use lighter barrel contours, as such, if you get to much length in the barrel you start running into barrel whip issues. the heavier and longer the bullet, the faster the barrel twist and the higher the velocity, the more stress is impossed onto the rifle and shooter. That is one huge benefit of the 338 bore size, it performs very well in 26-27" barrel lengths. Yes you will loose abit of velocity compared to a 30" barrel but in most cases its around 40-60 fps is all.
In a 28" barrel I would expect to see 2900-2925 fps with the 300 gr class bullets without to much trouble. I have built a 25.5" 338 AX that averaged 2890 fps with the 300 gr SMK.
To get a legit 3000 fps, I would say you would need a 30" pipe. In a much more portable rifle however you could get Well into the 2900 fps range and at long range you would never really notice the difference as far as performance goes.
Shootability wise, for a 1000 yard rifle, I like a min of 8 lbs bare rifle weight, scoped up ready to hunt with in the 10 lb class. Most healthy males can easily pack a rifle of this weight in most terrain without undue stress.
If the walking is on the moderate side I would personally much prefer to have a 12 lb class rifle and the reason why is simply because I shoot them better. In the field when rests can be less then perfectly even and square, a lighter rifle WILL always torque more then a heavier rifle. This in and of itself does not effect accuracy but it can effect how the rifle moves under recoil and that CAN effect down range shot placement.
We are often in a state of excitement in the field as well which means quicker breathing and increased heart rate. Even if we have time to relax and set up for the shot our heart rate will often be increase and that is generally in porportion to the size of critter we are shooting at!!!
A heavier rifle simply dampens our ill effects on the rifle as far as consistancy goes.
With the proper muzzle brake, good stock design and good recoil pad, you could get extremely light weight and still have a very easy shooting rifle, remember, with the partition style muzzle brakes, the lighter the rifle, the more effective they are at reducing felt recoil. A 7 lb rifle would be completely comfortable to shoot with a brake such as my Painkiller, BUT, it would not be overly easy to shoot at long range so again, we get back to that ballance.
With our modern muzzle brakes, stocks and recoil pads, recoil is really not an issue. Muzzle blast certainly can be but not recoil.
If your looking for the ultimate in performance to lb of rifle ratio, I would have to bet my 338 AM loaded with 265 gr Aluminum tipped bullets at +3450 fps in a 14 lb rifle would be very hard to beat but thats about as extreme as it gets unless you add another 4 lbs and get into a 34" barrel and then your looking at 3550 fps with a .88 BC bullet.
I have tested my Xtreme Heavy Sporters to 3010 yards with the above combo and even though it was an 18 lb rifle, it held 3/4 moa at this range and I would consider an 18 lb rifle to be a light weight when dealing with rifles designed to be shot at ranges over 2000 yards.
Still thats not a portable rifle for an all day hike, again, back to balance.
You can easily get into the 2800-2900 fps range with an easily portable rifle and thats with a 300 gr SMK. That is certainly not the only bullet around but its the standard all others are measured by for long range shooting. Lighter bullets offer much more velocity potential for sure but give up some ballistic performance.
