I have been experimenting with loads for my .308 FN SPR. It has a 26" 1:12 twist barrel. Thus far I have loaded 168 SMK's, 155 SMK Palmas and 150 AMAX's all over varying amounts of Varget. My next loads will be with 175 SMK's. Should I take twist rate into account when selecting various bullet weights to addres stabilization? If so, what is the optimal weight for a 1:12 twist 26" barrel, and why? I should add that I am only looking for accuracy and not stopping power. Any advice would be appreciated. I did perform a search of the archives but did not find anything definitive enough.
1-12" is a good all-around twist for the .308 Winchester. If you want to go by the books, a 175gr SMK is ideally spun by a 11.25 twist. Palma shooters use 1-13 or 1-14 for the 155gr bullets. The 1-10 is usually for the 190+gr bullets.
As in all things, it's a little subjective. First, what a manufacturer advertises as a twist rate may not be exact, and depending on the velocity, etc. most bullets have a tolerance for several twist rates. My 700VS shoots 175gr and 168gr SMKs great w/ a 1-12", and does great w/ some 185gr VLD's as well. Doesn't like 155gr bullets too much so far. Some people have reported shooting 175gr SMKs w/ good results out of 1-13" twists, etc.
I'd say a 168gr or 175gr are about as close to 'ideal' for the 1-12" as any, but others like the 155gr Palma SMK or a Berger 185gr VLD should work as well. Test it and find out.
S1, I looked up your recomendation on Midway. Is it the Berger Match 185 VLD Hollow Point? Also, any advice as to who would have the best prices on these as well as the 175 gr AMAX?
Thanks for the info.
Location: The rifle range, or archery range or behind the computer in Alaska
Re: Ideal Bullets for .308 26" 1:12 twist Barrel
I know what every body has told you about which bullets to use and all will work well, but if you want the best results for your twist, stick to the 180 SMK or the 178 AMAX, or the 175 SMK. There are new methods to getting the best bullets for twist NOT the Greenhill method. I am not saying the greenhill methods dont work but there are methods that work better. I have proven that the optimum bullet for 1-11.25" is in fact a 190 SMK not the 175. And the 175-180 works best in a 12 twist. My advice is try all and settle with what works best. But I have a feeling that 175's to 180's will work best, or anything that is in the legnth of around 1.300" I have a computer program that anylizes twists and which bullets are best for twist and velocity, so far it has hit the nail on the head. I have a 11.25 twist gun and thought the 175's were best, and they where good, but when I tried the 190's I started shooting .75"-1.000" at 300 yards all day every day. The computer told me it would be best and I could not belive that until I tried it. Also the velocity ranges for the bullets I mentioned would be 2700-2750 More stability than needed is a waste of time for accuracy, despite what some say, it also hurts ballistic coefficients. The right bullet for twist gives 2 advantages, 1: Accuracy, 2: better B.C's Give it a try. Try all and make your own conclusion. But whatever you try, make sure you try 1.300" bullets
Long range shooting is a process that ends with a result. Once you start to focus on the result (where the shot goes, how big the group is, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.