308 vs 6.5 Creedmoore

[roc1]

How does 308 really compare to the 6.5 Creedmoore 500 yards or less? The 6.5 Calibers are rated better long distance but within 500 yards is there really enough difference to matter? Just curious. Have great 308 thinking about 6.5 just not sure it would be better as in more accurate like I have read.
Thanks
Roc1

 

[Snyper]

For most shooters there are probably 20 or more cartridges that will perform virtually equally at 500 yds

Much of what is stated as "better" is personal preference that ignores too many variables

 

[Jimro]

roc1,

Yes there is a difference. Your question, is it enough difference to matter?, is very subjective.

My personal opinion is that 600 yards and under, the difference between cartridges is actually quite minimal. A 223 pushing a 77gr SMK will hold right up there with a 308 pushing a 175 SMK or a 6.5 Creedmoor pushing a 140gr SMK.

Beyond that 600 yard mark, is when the higher BC of the 6.5 bullets really starts to show a marked advantage in long range, as evidenced by the usage in F Class (along with 6 and 7mm bores).

Of course, at the last F Class nationals the scores dropped hard for the F Open class when the wind picked up, and the scores for the F/TR guys shooting 308s remained about the same. The guys shooting 308s ALWAYS have to account for the wind, and so they were more consistent in the wind. The folks shooting Open class are used to high BC bullets going fast, so don't have to take the wind into consideration as much.

But inside of 600, I wouldn't hesitate to reach for a 308, or a 223.

Jimro

 

[taylorce1]

Better for what is what I'd like to know, what's the main use? If it's strictly target shooting I think you'll find the Creedmoor easier to shoot because of the ability to use lighter bullets and smaller part wider charges. This means less recoil that will probably lead to smaller groups overall. If it's just for hunting isn't any real difference as shots will be minimal most of the time out of both rifles.

 

[roc1]

Target shooting only use 270 or 243 hunting
Thank

 

[Bart B.]

With the quality of bullets and barrels these days, there's no significant accuracy difference for all centerfire calibers from 22 up through 30 for those with the best match bullets available.

In calm conditions, the advantage to shoot them accurately (precicely?) goes to those with less recoil when shot off ones shoulder.

Shooting .22 rimfires at 100 yards equates to shooting .308 Winchesters at 800 yards. Wind drift for each mph of its speed deflects both about the same; .6 MOA. Yet the 20-shot groups shot with the 22 subtend smaller angles on paper compared to the .308 when both have the same 1/2 to 3/4 MOA accuracy level at target range and the .308's typically better. And in spite of the rimfire rifle having to be held still near 3 times longer after firing the round; it takes longer for the bullet to clear the muzzle as well as it moves less in recoil during that time. Both target's X ring's 1 inch; rimfires shoot more Xes per string that highpower ones.

 

[edward hogan]

Think Roc is on the right track. But go a bit further and look at the 6mm ctgs.

Accuracy theory is one thing, but why do the benchrest guys shoot .22 and 6mm almost exclusively. Why are the BR and PPC ctgs the only two contenders of any regularity?

GA Precision pioneered the 6mm Creedmoor in their DPMS AR-10 series rifles. 6mm Dasher is another longrange ctg from benchrest circles. The 6mm International, a .22-250 necked up to 6mm is a longtime semi-contender. David Tubb basically used an AI'd 6mm intl about .001" shorter in case body and called it the 6mmXC across the course, for match shooting at all distance with enhanced barrel life.

What are the characteristics that contribute most to precision capability or "accuracy" in hands of a capable shooter?
-high BC number bullet
-lighter bullet weight for less recoil and barrel whip
-lighter powder charge
-short, stout case which powder fills almost to capacity.
-short action receiver
-case with sufficient neck length
-case short enough to allow bullet to seat w/o protrusion into case body

All thing being equal in 2 rifles the smaller bore will be easier to shoot well.
.22PPC loses a bit to the 6ppc with the lightweight bullets at 200yds, so most benchrest shoot the 6mm to gain the points at 200yds and not give up much at 100...


If looking for 1000yd precision and anything under, the 6mm ctgs are the clear choice. See what chamberings the Tubb 2000 match rifle has options for. Where the shooter has option of choosing the best ctg, most are going 6mm. Maybe conditions at your home range dictate a 6.5 bore, but where conditions are neutral the best balance of Bullet BC, Velocity, & Low Recoil (Disturbance etc) will dictate the ctg selected.

 

[Kachok]

The 6.5 Creedmoore has a reputation for accuracy, not that the 308 is a slouch but the 6.5 has higher BC for less wind drift and less drop at long range, the 6.5 is ballisticly similar to the 300 Win Mag without all the recoil and blast.

 

[Bart B.]

No 26 caliber bullet has the G1 BC of Sierra's 30 caliber 240-gr. HPMK. It's over .700.

 

[Kachok]

Yes Bart, but how fast can you push a 240gr in a 308? What maybe 2,200fps if you are aggressive with the pressures, a Creedmoore can push it's high BC bullets 2700+fps no problem do the math on the trajectory and drift out to 1,000 and the Creedmoore wins hands down.

 

[Bart B.]

Normal max pressure ammo does it.

 

[roc1]

Kept my Savage 308 wife told me to buy rifle for Bday so I bought Savage LRP in 6.5 Creedmoore on its way from Buds. I have target scope on 308 I do have Vortex 6-16x and a very good Leupold but it's only 3x 9 probably need 16 power to get most out of rifle. May even take Weaver 36 power off 308 put on it. Decisions decisions
Thanks for inputs
Roc1

 

[reynolds357]

Berger has a .30 cal over .740 G1 BC.
The highest 6.5 mm I know of is .62.

Having said that, my new project is a 6mm shooting a .580 BC bullet. It is almost as flat at the .30-378 to 1k (1.4" difference), and is burning less than 1/4th the powder.

 

[Kachok]

OK in regard to these 240gr SMK bullets let's compare shall we.
308 Winchester 240 SMK 2,200fps at 1,000 yards w/200yd zero (for perspective only)
442.3" drop, and a 10mph crosswind drifts 76" maximum supersonic range 1250 yards
6.5 Creemore 140gr VLD 2750fps exact same conditions
297.1" drop and 70.1" drift maximum supersonic range 1400yards
So someone ANYONE tell me what advantage the 308 has even with the crazy heavy 240gr bullets? More recoil, more expensive more potential issues with bullet stability (unless you happen to have a 1:9 twist) how would anyone call that better?

 

[MrBorland]

I don't have a dog in this one, and I'm a 6.5/7mm fan, and largely agree with your assessment, but I'll bite anyway.

So someone ANYONE tell me what advantage the 308 has even with the crazy heavy 240gr bullets?

Momentum and penetration.

Using your data, the 240gr .308 will have 40% more momentum at 500 yards than the 140gr 6.5CM. That .308 bullet also has a bit higher sectional density. Factor SD in, and the 240gr .308 has 60% more penetrating potential than the 140gr 6.5CM.

Superior external ballistics are nice, but if you're hunting bigger game, or have to knock steel down, rather than just ring it, terminal ballistics matter, and the heavier bullet has a lot going for it.

 

[Kachok]

That would apply if we were talking about hunting, but even if we were talking about hunting the SMK is a **** poor choice anyway. They are not designed for expansion and they don't yaw reliably. So no for punching paper and defiantly no for hunting, the question still stands why would anyone want a 240gr bullet in a 308 if a 6.5mm is an option? Snipers use a 175gr bullet not a 200+gr because really the 180gr class bullets are about the upper limit of the 308 case in logical terms, reasonably high BC (around .500) at 2500-2600fps not a bad all around long range load but well shy of what a 6.5 Creedmoore or 6.5x55 can pull off .600+BC at 2700-2900fps and yes a 6.5x55 can drive a 140gr VLD/A-Max or 142gr SMK to 2900fps with RL22 or H1000 you won't find that load in any manual because of 100 year old small ring Mausers but they are well known.

 

[tobnpr]

Well...my question is, how accurate is the .308 you own?

Your original question seems to indicate it's not shooting as well as you'd like (or you wouldn't be considering a change)- but what do you mean by "great .308"?

How well does it shoot at 600? What are your components?

Nothing wrong with change for the sake of change...we all do it...

But at "only" 600 yards, improvements might be able to be made (barrel, ammunition) that could improve accuracy.

I think that most shooters would be hard pressed to discern a difference between the two -if driving equally capable rifles- as Jimro said.

 

[Jimro]

Kachok,

The OP specified inside 500 with the 308 Win and 6.5 Creedmoor.

At those ranges there just isn't much practical advantage any way you slice if for either cartridge.

Here is how I stack the two up against each other at 500 and under:

Recoil: winner 6.5 Creedmoor
Accuracy: Tie
Barrel Life: winner 308 Win (by a hair)
Energy: Tie
Momentum: winner 308 Win
Wind Drift: 6.5 Creedmoor (by a hair)

Honestly if all you are doing is punching paper, a 223 makes even more economic sense than either the 308 or 6.5 Creedmoor. You have to get beyond 600 for the 6.5 Creedmoor to start dominating the stats, mainly because of less windage adjustment. But even then a 308 pushing a Palma load will keep right up with the 6.5 Creedmoor in the hands of a skilled shooter.

Jimro

 

[tahunua001]

it's a bit of a wash. the 6.5 is flatter shooting, the 308 on average will have higher energy at the target...


personally, I love 6.5s and not as much for 30 cals. but between a 7.62x39mm, 303 brit, 7.7 japanese, 2x30-06, and a 300 weatherby mag already in my collection, I have absolutely no use for a 308. similarly between a 6.5 grendel(rifle length), 2x6.5 japanese(one rifle one carbine), and a 6.5 swedish mauser, I have no need of a creedmore either. I'm better setup to handle another 6.5 though so if I was picking the two, I would probably get the creedmore but for me neither is much of an interest.

 

[ranger56528]

Kept my Savage 308 wife told me to buy rifle for Bday so I bought Savage LRP in 6.5 Creedmoore on its way from Buds. I have target scope on 308 I do have Vortex 6-16x and a very good Leupold but it's only 3x 9 probably need 16 power to get most out of rifle. May even take Weaver 36 power off 308 put on it. Decisions decisions

Thanks for inputs

Roc1

I put a 6.5-20x50 Vortex Viper on my LRP 6.5 creedmoor.