I am considering a .308 Winchester for informal target and bench rest shooting.Everything else being equal-does a 20" bbl offer better (generally speaking) accuracy over a 24/26" bbl?? Any advantage of a barrel with 5R rifling?? Any advantages with cut rifling over button rifling. Thanks for help. Erod
Location: The rifle range, or archery range or behind the computer in Alaska
Re: >308 Barrel Length
I totally agree with JE on this one.
26"+ may not be the best choice for benchrest competition but is for 600-1000 yard match shooting.
I have seen BR quality accuracy out of all my 26" 308 barrels. None have offered BR accuracy with my hunting loads every day but then again, they were developed with high BC bullets at max velocity potential utilizing hunting weight rifles. BR accuracy being .150 or better.
With different bullets and lower velocities and more tedious loading tecniques while utilizing a heavier platform, I am pretty sure I could have seen .15 MOA groups more often than not with any of my 308's other than 1 wby I had which was turd.
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.
I'm not convinced barrel length has much to do with accuracy for the .308 Win. As long as it's long enough to get small velocity spreads for the powder used and long enough to get the bullet out fast enough for the rifling twist rate to stabilize it properly, great accuracy will prevail.
One issue with groove count as seen by top competitive shooters using wide ranges of bullet weights. Lighter bullets, such as 135 to 155 grains, tend to shoot more accurate from 4 groove barrels than 5 or 6 grooved ones. Why? I've no idea. Bullets heavier than 160 grains seem to shoot well in any groove count.
You did not say what type of target shooting you will be doing. A longer barrel may not be more accurate than a shorter barrel, but if your target shooting will include offhand shooting, a longer barrel may be easier to hold steadier than a shorter barrel. My suggestion would be to go to a shooting range and see what equipment they are using for the type of shooting you are interested in. Ask them questions about their equipment and why they are using that type of equipment. Most shooters are happy to talk about their shooting and their equipment. When you do get your rifle, you will probably be shooting alongside these very same shooter. Good luck and have fun.
I shoot a 20" barreled .308 TM700 Tactical. This is my goat culling/ dog tucker rifle and light recoiling back up rifle for hunting clients as an alternative to the 7mm Magnums.
Pro's of the 20" barrel.
Achieves 2840fps with 150 grain bullets.
Achieves 2660fps with 168 grain bullets.
Achieves between .250 and .4" groups at 100 yards with full power loads.
Loss of sight picture during recoil.
Upper end of recoil for newbies with full power loads.
I find the recoil acceptable but feel there is no need for it when a 24"-26" barrel would tame it right down.
Would be nice to get the 168 grain bullets shooting 140fps faster from a 24" barrel or 200fps faster from a 26" barrel (using Varget rather than the faster powders which work well in the 20" barrel).
For target work, if I wanted to stick with a 20" barrel, I would perhaps adopt a suppressor to dampen recoil.
I'm with Brimiy here. Need to know what sort of target shooting you're doing with this one to give you good advice. If you're into Palma shooting, a 29"-30" is pretty much required to get the velocity you need to stay supersonic @ 1,000 with a 155 grain bullet. If you're shooting across the course, a 26" barrel should be about right. The offhand and rapids dictate that balance be taken into consideration, and this is pretty much the norm among most shooters. Using a 26" barrel at 1,000 isn't a problem as long as you are using 190s or 200s (not an option for the Palma mentioned earlier), so yes, the type of shooting makes a huge difference.
Someone suggested that you go spend some time on the range with folks who are shooting they sort of competition you want to engage in. That's great advice. I'm sure most will be more than happy to tell you their likes and dislikes, and you'll be able to make a much more informed decision.