First, it is refreshing to hear someone have the option to go with a 308, 30-06, or 30 cal magnum and choose the 308. I'm having this same discussion on another forum and it is amazing how many people want to put down the 308. I am in a similar boat, but I only own a 308 bolt action as up here in New England, its really tough to justify anything larger. Our woods are dense, our farms/fields are smaller, lots of hills, whitetails are on the smaller side, No elk, Moose are limited draw, etc. etc. I am very comfortable with my Savage, and it is very very accurate. So rather than drop coin on a 30-06 for 150-200fps more or a magnum which would only see use once every couple of years for a trip out of New England, I decided to work with my 308.
I've been experimenting with heavy for caliber bullets. I know a lot of you on here are recommending the 165/168 grain range but wanted to share my results. The 180 Accubonds were incredibly accurate, and 200 grain partitions less accurate but still quite accurate for an exposed lead non-boat tail bullet. I decided to give the 200 grainers a shot because my rifle has a 1:10" twist and because the 200 grain partition actually as a shorter overall length than the 180 grain accubond. So realizing I wasn't really sacrificing case capacity, I gave it a shot. At the Nosler guide's max pressure it with 180's, I got to an average of 2530fps using 43.5gr Varget (ballistic calc says -10.27 inches at 300 yards with a 200 yd zero). Working up a load on the 200 grain partitions, I managed to average 2430fps at 46gr of Reloader 17 and -11.37inch drop. This was measured with a chronograph 4 yards from the muzzle. When I calculate for a 165 grain accubond, I'm coming up with 2730fps and -8.88 inches at 300 yards. This was all done using Nosler 308 brass and CCI 200 primers, at ambient temperature of 40 degrees, using a rifle with only a 20" barrel.
So the difference between a 165 grain accubond and a 200 grain partition using real world measurements is about 2.49inches, or roughly the size of a chapstick at 300 yards. Is that modest flattening of trajectory at what is probably the extreme end of the 308's effectiveness worth using a lighter bullet on such larger game?
I am planning on trying 180 grain partitions and Reloader 17 next to see if I can strike a balance between speed and weight, but anyone who shoots a 308 I would recommend spend some time researching about the guys who have used Reloader 17 to really push the envelope into 30-06 territory. Some guys have done so with great results.
