.308 standard vs varmint barrel twist rates

[simplicity]

     I've been pondering getting my hands on a heavy barreled .308 to add to my collection. preferably it is going to end up being a remington. I as looking through their catalog and noticed that the varmint barrels and their long range tactical 700s have different twist rates in the barrels. The normal standard light weight barrels have a 1-10 twist rate ( 700 bdl model seven sps etc.) and the long range and varmint barrels have a 1-12 twist rate, and their long range tactical has a 1-11.5 twist. If my memory serve me correct the 300 savage has a 1-12 and has a hard time stablizing bullets over 150gr. and that's why they went to a 1-10 twist for the 308.  According to remeington they went to the 1-11.5 cause it stablizes the 178gr. the best for long range.  To my knowledge and what I know to stablise a heavier bullet you need a faster twist rate. also all the other 30 calibers have a 1-10 ( 30'06, 300 win. etc)  Basically my question is why the different twist rates from a light weight barrel (normal hunting barrel) to a varmint barrel  to shoot the same weight bullets? This is the only caliber that I can find that they do it with and why particularly 308? If someone could fill me in on this I would love to and any answers be at technical as you'd like. Because this is really has my intreaging me.

[Val]

The slower twist rates such as 1:12 are indeed, to more optimally stabilize the lighter bullets for varmint shooting. The heavier barrels work better for shooting critters such as ground squirrels where a lot of shooting is the norm. The heavier barrels don't heat up as quickly as the lighter barrels. If the gun is going to be used for varmints get the slower twist.

[drdougrx]

Hey Simp...

Generally....Faster twist rates stabilize heavier and longer bullets.  Also...though I may be incorrect (not the first or last time I'm afraid)...the companies build rifles based on marketing and may build rifles in a particular way because they believe they will sell.  Most twist rates around 1 in 10 will stabilize typical bullet weights fairly well.  The typical twist for the 223 is 1 in 10 or 1 in 9.  Those rates will stabilize 50-68gr bullets fairly well...55gr being the mid-weight and among the most accurtare.  I have a Remington 700 lite varminter in 223 with a 1 in 14" twist...it will shoot 55gr bullets pretty well, 40gr bullets really well and 60gr bullets and heavier...terrible...they actually keyhole!  A 1 in 11.5 is not all that much faster than a 1 in 10 so I suspect, especially when one is looking for accuracy, max velocity may not be an issue and that particular bullet, that long 178gr match bullet, will stabilize at a mid-range velocity.

Hope this helps!

Happy Holidays!

[diggler1833]

Unless Remington changed something on me overnight it should be 1:11.25", not that a quarter inch is worth arguing over because it isn't.  1:12 twist rates are more than fine for just about any bullet you would want to shoot in a .308.  You should have no problem stabilizing the 175gr bullets in a 1:12, Marine snipers have been doing it for years, and at more modest velocities, not to the ragged edge (obviously having ammo out in the sun in 130 degree weather may have a small influence).

The advantage to say a 30-06 or 300WM with a 1:10 twist is that you should have no problem stabilizing bullets in the 210-220gr range, and shooting at larger, heavier game with them.  I know of a guy offhand and maybe another that have shot 208gr A-Max successfully out of a 1:12 twist .308.

Only advantage to a 1:10 twist .308 that I could think of is that you would have a very slightly better chance of stabilizing the 178gr A-Max at a rather slow velocity.

Unless you are going to carry the rifle around the hills all day long, go with the varmint contour barrel, you don't see many pencil barrels in benchrest competitions.

A Remington 700SS 5R is a great .308 rifle off of the rack for about $1K.  I had/have one and it was a very regular .5MOA shooter or better off of a bench out to a couple of hundred yards.