6.5 Creedmoor vs 308 Winchester
- Thread starter 46490
- Start date
What is the highest BC bullets you can stabilize with your barrel twists. What is the highest safe muzzle velocity you can obtain from each rifle (barrel length) - plug those into a balistics calculator and see which you like best - both will easily reach 1000 if you do your part, the 6.5CM will typically just do it a latter flatter - note typically - ymmv
This has been an age ol' argument since the Creed came out.
Find a ballistic calculator like JBM or Hornady's 4DOF. Plug in
what your shooting and the charts will tell what's doing the best
at all the yardages out to 1000.
For the Creed, I'd recommend 140 gr class bullets, on top of
H4350 or Reloder 16. Very easy to tune.
RegionRat
Gold $$ Contributor
If we just use some typical values for high class factory loads, assume 1000 yds drop, and a 10 mph cross wind.
A Berger 6.5 CM 153.5 LR Hybrid leaves the muzzle at 2702 with a G7 BC of 0.356, drops -306.45, drift 61.48
A Berger 308 WIN 185 Jugg leaves the muzzle at 2608 with a G7 BC of 0.283, drops -379.57, drift 88.78
Those numbers speak for themselves in terms of which of the two will have a ballistic advantage on the range. In each of your rifles, getting high quality bullets, with a higher BC, is typically going to be the key when going out past 600 yards. In 308, 175 and up unless the rules restrict you. In 6.5, roughly 140 and up.
That said, if you shoot 308 in Palma, there are going to be many folks up and down the line also shooting 308 Palma, and they shoot to 1000 yards. Rules can vary, so check with the clubs near you.
If you shoot 6.5 CM, you will be going up against folks in open class, who will likely not be shooting 6.5 CM. The 284 WIN and the derivatives are very popular for highpower and F-Class at 1000, and then you see the short magnums and magnums show up too.
My advice is to shoot what you got, as much as you can, as far as you can, and learn wind. Getting ammo put together is difficult these days so what you have in hand is more important than what is better on paper in the short term. As you plan forward, go study what the better shooters are using in the games you are interested in joining. If you stick with those guns, then you are looking for the higher quality, higher BC bullets.
A Berger 6.5 CM 153.5 LR Hybrid leaves the muzzle at 2702 with a G7 BC of 0.356, drops -306.45, drift 61.48
A Berger 308 WIN 185 Jugg leaves the muzzle at 2608 with a G7 BC of 0.283, drops -379.57, drift 88.78
Those numbers speak for themselves in terms of which of the two will have a ballistic advantage on the range. In each of your rifles, getting high quality bullets, with a higher BC, is typically going to be the key when going out past 600 yards. In 308, 175 and up unless the rules restrict you. In 6.5, roughly 140 and up.
That said, if you shoot 308 in Palma, there are going to be many folks up and down the line also shooting 308 Palma, and they shoot to 1000 yards. Rules can vary, so check with the clubs near you.
If you shoot 6.5 CM, you will be going up against folks in open class, who will likely not be shooting 6.5 CM. The 284 WIN and the derivatives are very popular for highpower and F-Class at 1000, and then you see the short magnums and magnums show up too.
My advice is to shoot what you got, as much as you can, as far as you can, and learn wind. Getting ammo put together is difficult these days so what you have in hand is more important than what is better on paper in the short term. As you plan forward, go study what the better shooters are using in the games you are interested in joining. If you stick with those guns, then you are looking for the higher quality, higher BC bullets.
STOMP442
Gold $$ Contributor
This boils down to which bullet you intend to shoot out of the .308. You need to compare apples to apples which in this case means heavy for caliber bullets. A 6.5 140-142 equates to a 200-210gr .30 cal projectile. Both cartridges are able to shoot that distance easily. The 6.5 as mentioned will typically get there a little quicker and a little flatter but the .30 cal in the 200gr range will generally be slightly more forgiving in the wind but will be much slower and require more elevation which really is no big deal. All depends what your rifle likes. If your .308 ends up shooting a 175 or 185 the best the 6.5 with a good 140 class bullet with equal accuracy will be superior ballistically at that range. Wind reading ability at that distance makes the most difference than caliber choice between the two with heavy for caliber projectiles.
I think it's a draw actually. Going with heavy 308 bullets you'll be close on wind if it comes out to play. Heavier bullets do make a difference in wind if BC is close. Recoil will be worse with the 308 with heavies (185-200). The 6.5CM will be flatter and easily better the 308 in good conditions. Much less recoil also using 140(.62 BC)class bullets. When I shoot my 308 with 200X(.64 BC) bullets and it's a draw accuracy wise. Drop is considerably more with the 308 and if wind is up, I'd prefer the 308 over the 6.5CM. Going to the 6.5-284, I'll take it over the 308 Everytime. It's not a simple answer I guess. Conditions would dictate at 1000 yards. 100-600 the CM Everytime. Truth be known, I'd probably chose the CM over the .308 as well in more cases than not. Tough to beat the 6.5 bullets in most cases from non-magnum cartridges.
As others have said. It largely depends on what load you are shooting especially in 308. Don't be that guy trying to shoot 168 Sierras at 1000.
mtncwru
Gold $$ Contributor
Hey now, what do you have against shotgunners?
rijndael
Silver $$ Contributor
Shooting bullets of similar BC at similar pressures, the 6.5m Creedmoor will push them about 200fps faster with significantly less recoil. 6.5 recoils less, shoots flatter and has less wind drift. The only advantage the .308 has is significantly more barrel life, like 3x as much, and that’s worth consideration too.
John
John
RegionRat
Gold $$ Contributor
@284winner ... "I think it's a draw actually. Going with heavy 308 bullets you'll be close on wind if it comes out to play. Heavier bullets do make a difference in wind if BC is close."
Sorry, not this time. Unless you are calling 61.5" and 75" close.
A Berger 200.20X has a G7 BC of roughly 0.328, at ~2800 ft*lbs has a MV of ~2525fps
A Berger 6.5 153.5 LR Target has a G7 BC of roughly 0.356, at 2497 ft`lbs has a MV of ~2702fps.
At 1000 yards, the wind hold for 10 mph on the 200.20X is 75" and the wind hold for the 6.5 CM is 61.5"
In practical velocity/pressure for 308 WIN and 6.5CM, the 6.5 CM will shoot inside the 308 WIN in any wind at distance using their respective heavy target bullets.
The muzzle energy difference between 6.5 CM and 308 WIN is only about 300 ft*lbs in favor of the 308 WIN, or roughly 2500 versus 2800 ft*lbs. Because of the physics of sectional density and mass, you just can't get the 308 WIN to shoot inside of a 6.5 CM when real bullet material densities and pressures are considered.
Sorry, not this time. Unless you are calling 61.5" and 75" close.
A Berger 200.20X has a G7 BC of roughly 0.328, at ~2800 ft*lbs has a MV of ~2525fps
A Berger 6.5 153.5 LR Target has a G7 BC of roughly 0.356, at 2497 ft`lbs has a MV of ~2702fps.
At 1000 yards, the wind hold for 10 mph on the 200.20X is 75" and the wind hold for the 6.5 CM is 61.5"
In practical velocity/pressure for 308 WIN and 6.5CM, the 6.5 CM will shoot inside the 308 WIN in any wind at distance using their respective heavy target bullets.
The muzzle energy difference between 6.5 CM and 308 WIN is only about 300 ft*lbs in favor of the 308 WIN, or roughly 2500 versus 2800 ft*lbs. Because of the physics of sectional density and mass, you just can't get the 308 WIN to shoot inside of a 6.5 CM when real bullet material densities and pressures are considered.
My velocities were 2600 for the 200X and I actually did 2800 for the CM. Kinda why I would go the 6.5 regardless. Less recoil and better numbers but what I will say is the numbers on the ballistic calculators aren't true real world numbers in big wind and at especially long ranges (2k+). I'll agree that at 1000 it's pretty fair to say that the 6.5 will be the clear choice. Tough to beat those 6.5 bullets at moderate to fairly long ranges. The .308 isn't the cartridge for anything beyond a 1000 yards either. Kind of a moot point since we're talking 300-1000 yards. RPR is the clear choice in any case here.
RegionRat
Gold $$ Contributor
Yes.
Long before the 6.5 CM came along, I was loading the 6.5x47 for my friends and talked them into the highest BC bullets we could find.
I still don't keep one for myself, but since the 308 WIN was on the lines next to 7-08 and 6.5-08, etc. it was clear what would out shoot what in wind.
In those days, it was hard to find the high BC bullets compared to now, but even then you saw the 6.5x47 shoot inside the 308 in mid range and long range matches. That said...
You have to give some credit to the Indian, not just the arrow. The folks who dedicate to Palma and F-T/R are some of the best wind callers I know, because they have to be.
Long before the 6.5 CM came along, I was loading the 6.5x47 for my friends and talked them into the highest BC bullets we could find.
I still don't keep one for myself, but since the 308 WIN was on the lines next to 7-08 and 6.5-08, etc. it was clear what would out shoot what in wind.
In those days, it was hard to find the high BC bullets compared to now, but even then you saw the 6.5x47 shoot inside the 308 in mid range and long range matches. That said...
You have to give some credit to the Indian, not just the arrow. The folks who dedicate to Palma and F-T/R are some of the best wind callers I know, because they have to be.
Straightshooter1
Gold $$ Contributor
I love shooting my .308, especially since components are pretty easy to get, even in today's market. I decided I wanted something better to shoot long distance and went with the 6.5 PRC. Am very happy with my PRC choice for shooting long distance, except that replacement components are terribly hard to find.
boltman13
Gold $$ Contributor
My advice based on shooting both 308 and 6.5 CM in the same rifles and different barrels, in F-Class. FWIW.
1) What are you shooting, Known Distance such as F-Class or Benchrest, or unknown distance like Precision Rifle, and are you planning on shooting for group and score, score only or to hit steel.
2) In F-Class you will be using the 308 in F-TR class off a bipod with an approximate weight of 18# including bipod. In F-Open you shoot off a rest and have a 24+# limit.
3) I have fired a 308 with a 200 grain bullet in a 1:10 twist barrel and there is a lot of torque to deal with and I never was able to deal with it to my satisfaction, nor the recoil of a 20 shot+ string. I had better scores with the Burger 185 Hybrid with less torque and recoil.
4) The 6.5 Creedmoor with a 1:8 twist and Berger 144 Long Range Hybrids is my prefered round in both my rifles a 31" Bartline, and a 32" Brux. The heavier rifle and lighter bullet produce noticeably less recoil and no problem with torque off a 3" wide front rest. I get +/- 2,850 fps here in the west at 4,500 ' elevation. Other threads on this post have demonstrated the superior ballistics of the 6.5 bullet over the 30 cal. To get the same level of ballistic performance in 30 cal. you are talking about a 230 gr. bullet which is a real chore for a 308, not to mention the added torque and recoil.
5) To be fair the 6.5 Creedmoor is not the prefered F-Open round. Most top F-Open shooters have gone to the 284 Win. or its wildcats, or the Rem. 7mmSAUM. The Creed gives excellent barrel life, almost as good as the 308 and far more than the hot 6.5/284 that at one time was THE F-Open round.
6) In Precision Rifle or shooting steel for fun the flatter trajectory of the Creedmoor will be of great benefit at 1K, but other rounds also offer this advantage.
7) The CM uses less powder and other components are about the same for high quality brass and bullets.
Best of luck.
1) What are you shooting, Known Distance such as F-Class or Benchrest, or unknown distance like Precision Rifle, and are you planning on shooting for group and score, score only or to hit steel.
2) In F-Class you will be using the 308 in F-TR class off a bipod with an approximate weight of 18# including bipod. In F-Open you shoot off a rest and have a 24+# limit.
3) I have fired a 308 with a 200 grain bullet in a 1:10 twist barrel and there is a lot of torque to deal with and I never was able to deal with it to my satisfaction, nor the recoil of a 20 shot+ string. I had better scores with the Burger 185 Hybrid with less torque and recoil.
4) The 6.5 Creedmoor with a 1:8 twist and Berger 144 Long Range Hybrids is my prefered round in both my rifles a 31" Bartline, and a 32" Brux. The heavier rifle and lighter bullet produce noticeably less recoil and no problem with torque off a 3" wide front rest. I get +/- 2,850 fps here in the west at 4,500 ' elevation. Other threads on this post have demonstrated the superior ballistics of the 6.5 bullet over the 30 cal. To get the same level of ballistic performance in 30 cal. you are talking about a 230 gr. bullet which is a real chore for a 308, not to mention the added torque and recoil.
5) To be fair the 6.5 Creedmoor is not the prefered F-Open round. Most top F-Open shooters have gone to the 284 Win. or its wildcats, or the Rem. 7mmSAUM. The Creed gives excellent barrel life, almost as good as the 308 and far more than the hot 6.5/284 that at one time was THE F-Open round.
6) In Precision Rifle or shooting steel for fun the flatter trajectory of the Creedmoor will be of great benefit at 1K, but other rounds also offer this advantage.
7) The CM uses less powder and other components are about the same for high quality brass and bullets.
Best of luck.
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