12-10-2012, 06:49 PM
Join Date: Aug 2005
My Ride: F30 328i M Sport
The 6.5mm cartridges are all based on a .308win case necked down to a 6.5mm bullet. There are just different dimensions for the case. The main four cartridges that are being used are .260Rem, 6.5 Creedmoor, 6.5x47 Lapua and 6.5x284. If you want a bolt rifle and don't plan on going beyond 1200yds, I would recommend going with a 6.5mm bullet class. .260Rem and 6.5 Creedmoor are are the most commercially available. These loads have less recoil than .308, but they have a higher ballistic coefficient due to a much longer bullet design. The trajectory of a 6.5 out to 1000yds is around an 8 mRad drop (66" drop), while a 175gr .308 will be around 11 mRad (99" drop). The trajectory is actually flatter than the 190gr .300 Win Mag out to 1000yds. 6.5s also don't burn out the barrel very fast. .300WM are known to burn out barrels at around 1500-2000 rds, depending on barrel construction.
Originally Posted by david05111
For years I wavered on caliber choice as far as what I wanted to look for in a precision bolt gun, but I basically had narrowed it to .308, 30.06, and .300 winmag. I honestly don't know too much about the .260/6.5mm cartridge.
I personally decided that I'd set my sights on one in .300 winmag, the primary reason being that I felt that the .308 platform was transitioning away from bolt to SA battle rifles. I guess I was right. And I'm not surprised to hear that they are performing as well as they are and that they're replacing the bolt guns on the battlefield, at least in .308.
I'm tempted to build one myself, but its a tossup. I could build a really nice SA .308, but I would probably be in the $5000-6000 range with optics by the end of it i think. At that rate, I'm into new or very nearly new Accuracy International bolt money and I think that's where I'd rather spend it, though probably a bit foolish.
I read a report a while back where it was pointed out that if you wanted a magnum long range caliber, you were better off with the .338 Lapua. The barrels last nearly twice as long as the .300WM, and you have a better trajectory. Ammo is a more expensive, but if you handload/reload, it's about the same cost.
If you are looking at a .308 on a high end gun, you're almost better off looking at a semi-auto.
That, or consider a modular bolt action like a DTA SRS. You can get it in .260 or 6.5, maybe get another .308 or other caliber if you want, and then get a conversion kit for .300WM and .338LM. I am likely going to be picking up a DTA SRS down the line so I can have a .260 and a .338LM.
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Last edited by Reedo302; 12-10-2012 at 06:49 PM.