F-TR .308 Barrel Lenght / Twist

[Dgd6mm]

I would like to know what the prefered barrel lenght is for a .308 to use in F-TR. Also what twist for 155 -190 grain bullets. Any info will be a big help, thanks much.
Don Dunlap

 

[Shynloco]

I can only comment on the twist rate in a .308 and for that bullet weight: 1:10 or 1:12. Mine is a 1:10 and loves 168's or 175's, but I'm now testing 155's that on the first group shot good groups@100 yds. I believe they'll improve.

 

[jonbearman]

Well the savage ft-r barrel is 30 inchs long and weigh's a ton.LOL I would think with others I own,I prefer 26" with the .308.Now I am sure that someone will chime in on how long a tube for proper powder burn is needed.

 

[s1rk1118]

Minimum 30" to keep all bullets above transonic (1.2 mach) @ 1000. 11 twist will work with bullets in your range (155 to 190).

 

[Scott Harris]

30" or longer for 1K shooting. 26" or less if you won't shoot more than 600 yards.

 

[tiny68]

I recently built a 308 for my 12 yr old to start shooting FT/R soon. We went with a 28" 1:11 twist for the 175 SMK. If you shoot the 175 SMK or Berger VLD, then you can get plenty of velocity even with a 26" at 800 ft using those higher B.C. bullets. If you want to shoot the 155s for Palma, then go with the 30" or 32". I played a lot with the 168 SMK trying to make it work at 800 yds in my 26" 1:10 twist 308. It can be done at higher altitudes but is tough at 800 ft were I live. Forgot 1000 yds.

A 30" barrel is great is you want a dedicated rig for shooting F/Class. However, you really limit the utility for other purposes with such a long length.

The 308 tab on the 6mmBR home page is a good read and has a section about barrel length worth looking at. See http://www.accurateshooter.com/cartridge-guides/308win/.

Luck, Tim

 

[glo]

First you want a 30” SS Palma Barrel. Second you should decide what bullet you are going to use. Third match the barrel twist rate to the bullet you are going to use.

The truth be known, short of 3000 yards it's unheard of that a bullet is over stabilize. Yes if you are shooting 100 or 300 yards then even with a boattail your groups will be spread because is takes 300 plus yards for the bullet to “sleep”. That is to settle in due to tail turbulence. Boat tails actually cause more turbulence than flat bases, but that's another story.

If you truly want to use more then one bullet, use the fastest twist rate. Remember you lose energy to the bullet the faster the twist rate. A good amount of energy goes into spinning the bullet. The lost energy will show up in your muzzle velocity.

Also if you use a reamer for a 155 grain bullet you will have to seat heaver bullets deeper. Thus you will loose case capacity. This of course if you are using bullets with the same general profile.