I have a Md.700 short action on hand and want to have a long range rifle built.I will use it for targets and deer hunting.My 'smith suggested having a 6-.284 built,but most of what I have seen on the forums suggest a 6.5-.284.Would someone tell me the advantages and disadvantages of these two?
Since you are thinking hunting, go 6.5-284. Heavier bullets that are way more effective on game at distance. Load 142gr MK or 140gr SST/Amax and have at it. The 139gr Lapua are well regarded but have not personally launched them so can't say.
If you want a lighter bullet for the 6.5, there are plenty in the 105 to 120gr range that will work just great.
Lots of if's with these two....the 6mm is a little cheaper to shoot as far as bullet costs, and you can shoot some lightweight bullets if your twist is slow enough at blistering velocitie,s if that's your game..the 6.5 is extremely accurate at super long ranges...both require some handloading skills at a level above novice, you need to neck turn..neither is easy on barrel life, lots of powder for a small hole...why don't you just settle on a .260 Rem or 260 AI..on and on this could go..they both have their place in the shooting world for sure..it all depends what you want to put into it..if you hate handloading and trimming and turning don't bother with either..you need lots of time to mess with the fancy little screamers..how about a .243 AI or .260 AI or even the regular versions..the difference is only a hundred or two FPS..the animals will never even notice that little of a difference.