Remington's Sendero SFII. Mines in 300RUM, but I've heard the 300WM is very accurate.
I agree with most everything you said sir. I have a ruger 77 sang safety with a 24 inch bbl on her and a vortex MOA. I believe that with a good understanding of the elements of long range shooting and the MOA or MIL dot systems either one, one can do an excellent job of range finding. I have found my MOA scoped 300 wm to be right on the money +- 5 yrds If it's good enough for Carlos Hathcock its good enough for me !Well there are several pluses and minuses to consider. First of all the 300 Win Mag holds the 1000 yrd any sight record at Camp Perry and has so for over ten years. Minus sides: The brass is expensive and barrel life is short (approximately 500 rounds). The rifle that set the record did so with a Ray Steele chamber from Dave Manson. There is much more than just maker and caliber selection to achieving a outstanding long range rifle as is pointed out above.
A good scope is critical and this is not based on name brand but scope performance as you have to be confident in your adjustments repeating and this is easily determined in about 10 rounds and is done by shooting a 3 shot group at 200 yard or 300 yards. After shooting three shots crank up 20 clicks, right 20 click, down 20 clicks and left 20 clicks and shoot another round. The fourth shot should be within the first 3. Next click 20 left, 20 down, 20 right and 20 up and shoot again. Continue this until you do the 20 drill in all four quadrants. If the scope is on the money you will have your answer.
At 1000 yards a 100 fps variation in velocity will give you a group 40" high. Thusly a 50 fps will give you 20" and so on. You need to be able to produce ammo that has an extreme spread of around 25 fps and preferrably 10 fps. (Hint: weighing each charge is only the first of multiple steps to achieve this)
Assuming you have that you need to have the technique that will enable you to achieve consistant aiming and shot let off every time.
You need to be able to read mirage and know what to do in the wind because any felt wind will move your point of impact a minute or better. If the wind is brisk 3 to four minutes (Minute is about 10" at 1000 yards).
Range determination is absolutely critical. You have to have a ranging device that will give you accurate readings within 5 yards. For instance when a long range shooter goes from 600 to 800 yards with 308/30.06 first thing he does in crank up 10 minutes or 40 clicks. From 800 to 900 20 clicks and from 900 to 1000 24 clicks and this is just a rough estimate as shooting in extreme weather differences and elevation will really do it to you.
For instance back in 70s one year I won 3 of the 4 1000 yard matches at Oak Ridge,Tennessee so one would think I had a good zero right? I went to Camp Perry and had not touched the sights and I wasn't on paper the first shot at 1000 and the target is 6'X6'.
I would recommend you take a two gun approach. First is get a 308 or 30.06 heavy barrel and perfect your load development and skills in reading the wind, good technique etc. The Sierra 175 gr. MK bullet is the standard bullet for the M24 Sniper Rifle. Acceptance on this ammo (if I remember correctly) is 10" horizontal spread and 20" vertical spread at 1000 yards. But if you do your part you can reduce this to around six inches.
As indicated 300 WM holds the record but if I am not mistaken 6.5X284 has won everything at 1000 yards at Perry for years now. It has a much flatter trajectory with Sierra 142MK (and there are other excellent bullets i.e. Berger etc) If you load this to 2985 fps you should achieve a flatter trajectory. I would recommend Quick Load program as an initial investment. Brass for the 6.5X284 is very expensive as well.
Finally there is a more affordable combo and you can achieve this and shoot more for less money. For instance you could obtain a Rem 700, Mod 70 Win, Savage etc in hunting rifle configuration and rebarrel it to 308 Win for your training. A 308 barrel will hold up for 3500 to near on 10,000 rounds if you get a good barrel to start with. The magums are getting iffy at 500 rounds and the 6.5X284 has about a 700 round life but there is a cheaper 6.5 to be had. 6.5X06 A Square which is a 30.06 case necked down to 6.5MM. It has same propellant capacity as does the 6.5X284 but brass is far more affordable. My first choice for such a project would be Mod 70 Winchester long action that had a previous life as 270, 280, 30.06 etc.
Again load development is critical and RL22 will put you in the sweet spot for 142 which is 2975 to 3000 fps. Below that the next sweet spot is 2675 to 2700 fps. This could be achieved both ways. Your initial chambering could be for 260 Rem and then move up to 6.5X06.
I just barreled up four of them in last two weeks for myself and friends as we are going to do a test series. I have chambered them with a custom dimension 6.5X06 AS which calls for a very tight neck, and turned necks on cases and a very small case body. Necking down 30.06 to 6.5 will give you about .294 neck dimension. When you clean up the necks with a neck turning tool they go down to .290-.291 range so I ordered my reamer with a .292 neck. Factory dimension is .299 neck. The case body was ordered at .2675 as new 30.06 cases are .465 on base. Fired cases come out of the gun at .466 so case life is expanded tremendously.
I have a 30.5" barrel shooting 50.3 gr. RL22. I can zero it for 600 yards and hold 23/24" low at 300 to 400 and achieve center hits.500 yards hold under 15" and 200 yards hold under 20" and 100 hold under 11". The come up from 600 to 1000 is only about 16 minutes.
Another consideration is recoil. A magnum is a punishing thing for a long string which is why I don't shoot mine any longer. The 6.5 is mild and about 1/5th the recoil. To make a 300 win mag comfortable the long range shooters rifles weigh about 16 pounds dressed out.
As others have pointed out there are lots of things to be considered to achieve top scores at 1000 yards and beyond that it gets worse. Shooting is kind of like stock car racing. Just because a Ford wins at Darlington doesn't mean you can go down to Ford dealer, buy one and be competitive with them. Last I heard the only thing used on a NASCAR unit and a family car is the hood. Then again they are not running ethenol gas either ! ! ! ! ! As well the average guy has never set in a car that will cruise at 200 much less driven that speed ! ! ! ! !
Hit me with a PM for further info if I can help.