I've been looking into appropriate long range (1000 yd and under) calibers now for a while, trying to make up my mind for a new rifle. I saw on the sierra website that their advertised BC for a 7mm 180gr Matchking is 0.660 @ 1650 fps (!) compared to the .30 caliber 220gr SMK with a BC of 0.629 @ 2100 fps. This has certainly piked my interest and made me lean toward some sort of 7mm magnum for this build. The rifle will be almost entirely custom, with a lilja 3-groove barrel or schneider poly barrel if it's a barrel burner, so barrel seating and twist rates shouldn't be a problem for these heavy bullets. I also handload, so a lack of commercial loads shouldn't be a problem, though brass availability and price should be taken into consideration. This rifle will be used mostly for target shooting, but may also see informal competition and/or hunting use as well.
Anyway, now that we've gotten those things straightened out and a caliber specified, which cartridge will be most effective at pushing these suckers downrange? I've looked through my handy-dandy Hornady Handbook of Cartridge Reloading (8th edition) and discovered the 7mm Weatherby Magnum. It's based on a shortened 300 Weatherby case and has all the other traits associated with it. According to Hornady it will shoot a 175 grain bullet at 3000 fps with approximately 4-5 grains less powder than a 7mm Dakota and approximately 10 grains less than the 7mm STW all from a 26" barrel, a significant difference. Whats more, the Hornady data for the Weatherby includes muzzle velocities up to 3100 fps whereas the Dakota and STW are limited to 3000 fps from the same length test barrel.
Has anyone on this forum achieved the claimed velocities?
Any caveats I have failed to mention?
Does anyone have real-world feedback to share?
Are there any other options I should look into?
Since the weatherby burns less powder, it should
prolong the barrel life over the other cartridges I mentioned, that's what attracted me in the beginning. Does anyone have feedback on this point?
On a side note, will the weatherby fit into a .300 Win Mag magazine? the dimensions that hornady specified put it only 0.02" longer and the same belt diameter as the win mag, is this a significant enough difference to complicate feeding or loading?
Also, I'm open to other ideas for in terms of calibers and cartridges if you make a good enough argument...
Thank you guys in advance. Your expertise has been very valuable in the past and hopefully will continue to be in the future.