6.5x55 or .308...new project

[Adam]

I have a savage 110 long action. I have a line on two barrels: a 6.5 1:10, and a 30 cal 1:12 (I think). Both are 30"x1.25" chromoly blanks by Douglas. I believe they are the premium line (the barrel model escapes me). My intention is to be shooting between 100 and eventually 1000 yards.

I am aware that the .308 is a short action cartridge. However, I will be shooting it as a single shot. I plan to run the 155 to 168gr in the .308 and 140ish in the 6.5. I would prefer to have a 1:8 twist on the 6.5 barrel. For those of you who run the 6.5, what load are you running with the slower twist?

Since the components are readily available, which would you choose and why?

Thanks,
Adam

 

[CyaN1de]

I believe a 6.5 with a 1:10 twist will limit your bullet weight to around 120grain Max. (I could be wrong on this)

I am currently awaiting my reamer and dies for a 6.05-08 and will be using a 1:8 twist Krieger barrel to lob 140grain bullets for 700m - 900m+ F-Class competition.

Berger recommends a 1:9 or better for their 140's.

 

[no one]

With the 30 inch barrel, you might be able to get enough velocity with the 6.5 to shoot 140 grain bullets satisfactorily. I suggest you use one of the twist rate formulas and find out if that will work. If I understood the variables correctly, bullet weight, twist, and velocity were factors. If you could drive a heavy bullet fast enough, you could get decent results with slower twist barrels. I'm certain someone with better knowledge of the formula than I will correct this information if it is in error. In any case, you will be able to get plenty of velocity out of a 120 grain bullet in the 6.5. One of the two loadings for Hornady's new 6.5 creedmoor is a 120 AMAX. This cartridge is intended for 600-1000 yard shooting.

Just because you shoot a 120 grain bullet doesn't mean this barrel/twist rate won't work at longer ranges.

 

[Leeper]

The 10 inch twist is likely to be too slow for 140's but will work fine with 120's.
In the 308, the twelve twist will work with anything you are going to want to shoot up to 200 Match Kings. Regards, Bill.

 

[tigrr]

My 308 30" barrel has a 1-12 twist and it likes 155gr bullets. .202@100yds
My 6.5-284 30" barrel has a 1-8 twist and it likes 139 grain bullets. .212@100

There is so much good info out there about the 308 and its a good accurate cartridge to shoot. 46grains of Varget behind a 155gr bullet, shoot. tweak later!
The 308 components are 2/3rd the cost of 6.5-284s.
308 Bullets - $36 pr 100, Lapua brass $66 pr 100, Powder -$15 pr 100. Primers $3.99 = $120.99 pr 100.
6.5-284 Bullets $37 pr 100, Brass $98 pr 100, Powder $24 pr 100, Primers $3.99 = $162.99 pr 100. 120.99 divided by 162.99 = 74% Save money shoot more.
308 dies are 1/2 the price of 6.5-284 dies(Redding comp dies). 5 company's make competition bullets for the 308, fewer company's make competition bullets for the 6.5, available where I live.
Barrel life - 308 is good for 5000 shots, 6.5-284 is good for 1000. 6.5 -55 ?

If it was me I'd go for the 308 with the 1-12 twist.
I didn't see the 6.5-55 part!!

 

[Obtunded]

The 30 cal 1:12 will stabilize up to 200 grain bullets, the 1:10 6.5 will be safe for shorter bullets or those up to about 130 grains and driven hard.
If you want to shoot ultra long distance, build a rifle that will take the heaviest, highest BC's you can for the caliber. 1:8" is a standard 6.5 twist for a reason.

Tigrr is not accurate about the 1000 6.5 round counts for ther Swede; you will get more than twice that and he is also incorrect about the companies making match bullets. I can think of a half-dozen immediately available in Canada

I have 6.5 1:8's in stock if you want an alternative choice.

 

[CyaN1de]

With the 30 inch barrel, you might be able to get enough velocity with the 6.5 to shoot 140 grain bullets satisfactorily. I suggest you use one of the twist rate formulas and find out if that will work. If I understood the variables correctly, bullet weight, twist, and velocity were factors. If you could drive a heavy bullet fast enough, you could get decent results with slower twist barrels. I'm certain someone with better knowledge of the formula than I will correct this information if it is in error. In any case, you will be able to get plenty of velocity out of a 120 grain bullet in the 6.5. One of the two loadings for Hornady's new 6.5 creedmoor is a 120 AMAX. This cartridge is intended for 600-1000 yard shooting.

Just because you shoot a 120 grain bullet doesn't mean this barrel/twist rate won't work at longer ranges.

It is the bullet length that will actually determine what twist rate is needed, the length goes up as the weight increases.

Pushing a bullet through the barrel faster will not get it to spin any faster than shooting it at a slower velocity. The twist rate will determine how fast the bullet spins, velocity will determine how fast the bullet reaches the end of it's flight.

 

[Adam]

Thanks for the input guys. I think the .308 is the way to go.

Adam

 

[crout]

Some of this stuff is true for a 6.5x284 and other such wildcats but not for the rest of the 6.5's

The 308 components are 2/3rd the cost of 6.5's. Save money shoot more.

NOT EVEN CLOSE. Lapua bullets(and most others) are actually more $$ than 6.5mm, Brass is the only thing that is gonna be cheaper. but if you think about it 200 pieces of most 6.5 cartridges will give you 5 minimum reloads(thats 1000 rounds) a 6.5x55 will give you 10 minimum reloads easy, that will outlast any barrel. and all for a difference of $30 for 200 pieces of lapua brass. did i mention you use less powder and the bullets are cheaper

308 dies are 1/2 the price of 6.5 dies.

6.5x284.maybe more $$ but not twice the price.

5 company's make competition bullets for the 308, fewer make competition bullets for the 6.5.

Let me think. Sierra matchking, Lapua scenar, Hornady amax, berger, nosler J4, Norma, plus another hand full of smaller business that make 6.5mm for competition. I can think of 2 off hand, forgive me if i forget the names but one is canadian.

Barrel life - 308 is good for 5000 shots, 6.5 is good for 1000..

true for the 6.5x284 not true for 6.5x55 or 6.5x47 or 6.5-08(others?)

The only thing cheaper about running a 308 is the brass. depending on what 6.5 you would have built the 308 even uses more powder.

 

[riflebuilder]

I shoot 6.5x55 while my brother shoots a 6.5-284. there is not a lot of difference between the two. Both perform best with the 140 wildcat (canadian made) about 3050 to 3100 fps. I think a 6.5 is a better bullet for long distance shooting than any 308.