.308 "Obsolete" Article vs 6.5 CM

[treillw]

I recall seeing a snipers hide article saying that the 308 is obsolete or something of that nature compared to the 6.5 CM. I searched around an wasn't able to find it. Anybody know where it is?

Thanks!

 

[EXTREMEPREJUDICE]

LowLight had an article posted on Scout titled close to "It's 2015 Time to Replace your .308." I can't find it in any archives, he probably has it somewhere. The best I can come up with now is https://www.snipershide.com/2017-year-of-the-bullet/

 

[spife7980]

Not one of Franks articles, I think all of those old scout articles went the way of the dodo with scout, but it still hits on the major points
http://precisionrifleblog.com/2015/0...tridge-matter/
It expands on it a bit deeper in the "other posts in this series" links
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[Lowlight]

Yes, it was on Scout and I finally got them to take everything down. That one article I do not have and did not bring it over. Too has changed since 2015 to be perfectly honest. With stuff like Lapua Brass for 6.5CM and other changes, the 2017 Year of the Bullet is a bit more up to date.

The Scout stuff is all gone, thankfully. And I do have most of it backed up, especially the video stuff.

I can address a direct question you were hoping to answer with the article.

 

[Fishkat]

I have two 6.5's, one a custom Rbros build and the other a DTA A1 but I've also got a 308 barrel for the DTA and enjoy shooting it. Short barrel, Varget is easy to pick up has are the SMK's. It's my go to caliber when H4350 supply gets low. Now the 6.5, I can't begin to say how much I enjoy shooting. The 308 is my insurance policy.

 

[TheGerman]

What's the energy on target difference between a 140g 6.5 and a 175g 308 at 400,600,800 yards?

Not near where I can calculate it; honestly curious.

 

[steve123]

This kind of stuff is interesting!

I saw something very similar to this, both vertical and horizontal component with 6x47l, 6.5x47L and 6.5 Saum just yesterday. At 1122Y we were shooting at a 18" plate in windy conditions approx 8 -12 mph coming in at 1 -2 o'clock. Myself with the 6x47 and one friend with his 6.5x47 struggled to hit steel. We were continually adjusting from our last shot but wind had changed enough so that we barely missed a bunch of times.

Other friend gets up there and hits the same plate pretty well with his 6.5 Saum. That extra almost 400 fps with 140 hybrids makes more difference than i'd thought seeming x47 is no slouch. His 6.5 4S isn't quite as accurate at 100y as ours either and actually his RCBS summit press had some screws come loose which "screwed up" the shoulder bump so he was trying to shoot up the rest of his reloads to start fresh.

Over the years when I'd go out to a old long range spot out in the forest service, guys would be shooting their 308's with typical 168 FGMM. Shooting 6x47l I'd easily hit the same steel that they struggled to hit in the wind.

At our AZPRC match back then, which could be very hard on windy days, we'd see new guys with 308's who thought they were rifleman not even hit one steel 0/40. A few of those guys never showed up again. On another occasion I watched a famous and well respected rifle instructor have to dial on 5 mils for wind - 308/175gr, for our 1080Y steel and miss both shots by quite a bit, both sides of the steel. The same one I hit with 2.5 mils holdoff.

Yes I know about the flatlines and juggernauts, etc, but still.

Gonna have to try those flatline 122's going about 3500 fps in my 6.5 Saum on that 1122Y steel!!!

 

[Supersubes]

What's the energy on target difference between a 140g 6.5 and a 175g 308 at 400,600,800 yards?

Not near where I can calculate it; honestly curious.

Theyre almost dead even at 400, and the 6.5 is pulling away from there. If you run it out real far the .308 starts clawing back some of the deficit, but it's still way off in drift.

 

[mark5pt56]

The WEZ sure does put things in perspective. Speed and BC

 

[mattp8893]

This kind of stuff is interesting!

I saw something very similar to this, both vertical and horizontal component with 6x47l, 6.5x47L and 6.5 Saum just yesterday. At 1122Y we were shooting at a 18" plate in windy conditions approx 8 -12 mph coming in at 1 -2 o'clock. Myself with the 6x47 and one friend with his 6.5x47 struggled to hit steel. We were continually adjusting from our last shot but wind had changed enough so that we barely missed a bunch of times.

Other friend gets up there and hits the same plate pretty well with his 6.5 Saum. That extra almost 400 fps with 140 hybrids makes more difference than i'd thought seeming x47 is no slouch. His 6.5 4S isn't quite as accurate at 100y as ours either and actually his RCBS summit press had some screws come loose which "screwed up" the shoulder bump so he was trying to shoot up the rest of his reloads to start fresh.

Over the years when I'd go out to a old long range spot out in the forest service, guys would be shooting their 308's with typical 168 FGMM. Shooting 6x47l I'd easily hit the same steel that they struggled to hit in the wind.

At our AZPRC match back then, which could be very hard on windy days, we'd see new guys with 308's who thought they were rifleman not even hit one steel 0/40. A few of those guys never showed up again. On another occasion I watched a famous and well respected rifle instructor have to dial on 5 mils for wind - 308/175gr, for our 1080Y steel and miss both shots by quite a bit, both sides of the steel. The same one I hit with 2.5 mils holdoff.

Yes I know about the flatlines and juggernauts, etc, but still.

Gonna have to try those flatline 122's going about 3500 fps in my 6.5 Saum on that 1122Y steel!!!

This post is exactly why I was asking peoples opinion on a 6.5 saum in a shorty. I've got an itch to do a 16 inch bolt action and was really wanting to do it in a saum to keep speed up and still shoot atleast 130s instead of running a creedmoor


Sent from my iPhone using Tapatalk

 

[lash]

What's the energy on target difference between a 140g 6.5 and a 175g 308 at 400,600,800 yards?

Not near where I can calculate it; honestly curious.

.308, 175g SMK, 2650 MV

400 - 1528 ft.lbs​

600 - 1104​

800 - 772
1000 - 522​

.260 (6.5), 139g Scenar, 2760 MV

400 - 1463 ft.lbs.
600 - 1131
800 - 859
1000 - 638​

 

[Mike402]

This kind of stuff is interesting!


Yes I know about the flatlines and juggernauts, etc, but still.

I'm glad someone mentioned this. Definitely doing the .308 a disservice by using an antiquated pedestrian load for comparison purposes. There are new factory options with 185 Juggs, and all kinds of bullet options nowadays to close the gap. I am personally using a 180 flatline with a G1 of .712 at 2888 fps in my 26" .308 (magspeed capture below) and feel like its very competitive to the 6.5s. Yes it does come at a cost disadvantage though, and yes I am aware you can also use solids in the other calibers as well.

I decided to rebarrel in .308 again to take advantage of the long barrel life, and the fact that I could use Flatlines if I need the extra oomph at distance.

 

[lash]

Obsolescence is in the eye of the beholder, or, to put it another way, obsolescence is dependent upon the application and needs of the shooter at that time. Anyone who thinks or says that the .308 is obsolete is thinking/speaking from a pretty narrow perspective. As noted already newer projectile design has given new life to many of the older "obsolete" cartridges. By the same token, those same improvements in design are usually being applied to the other 'newer' cartridges too.

I don't think that I'll ever not have a .308 rifle. Just like I still like my .338, when the .375 Cheytac and possibly even the 300 Norma Mag are superior choices for the ELR game. Heck, I still like the venerable .30-06, even though it's case design puts it at a disadvantage when compared to others.

 

[TripleBull]

Good stuff, Lash.

I may be obsolete but not my 308

 

[Jedi]

Many moons ago i spent considerable time researching and comparing various options to replace my 308.
This was back when anything but varget n 175smk was considered blasphemy, so me touting the 155 skinnie was met with howls from the old guard here.
Form factor wise the slightly longer sleeker of the two bullets via simple eyeball side by side comperison is the 155 skinnie, bc wise about identical.
However the skinnie can be ran 150-200fps faster, i maxed my rig out at 3050fps zero ill efect on brass etc, bug holes and single digit sd/es at 300yds
So my current rig shoots inside a hot 155, ultilizing a 6" shorter barrel.
308 was long in the tooth 10yrs ago, many more options now so why handicapp yourself.
Barrel life? Look at what the 6.5 gap guys are saying add melonite 5k would not surprise me
6.5 saum 20" barrel running 147 will about do anything you want n more

 

[Petrov]

I run old sierra 155 SMKs in my 308. When people ask me what bullet I run I tell them 155 Palma bullet and I get blank looks.

 

[TheGerman]

.308, 175g SMK, 2650 MV

400 - 1528 ft.lbs​

600 - 1104​

800 - 772
1000 - 522​

.260 (6.5), 139g Scenar, 2760 MV

400 - 1463 ft.lbs.
600 - 1131
800 - 859
1000 - 638​

My 175 is going 2774 (faster than the listed 139g round) so I'm thinking that may put the 308 on top energy wise at least in this comparison. I'll look at JBM and see what it says because target energy matters as much to me as exterior ballistics. With this in mind, I'm starting to dabble with the 185g as well in 308.

Now here's a question as I don't know how the target energy on the target (terminal ballistics wise) is translated from the ft lbs of different projectiles. Fragmenting rounds like the M193 aside as well as assuming its the exact same bullet construction, how does this scenario work as far as listed ft lbs:

175g 308 hits at 1400ft lbs

140g 6.5/260 hits same target at 1400ft lbs

77g 5.56 hits same target at 1400 ft lbs

Since the 308 is 35g heavier and slightly larger than the 6.5 and both are larger and heavier than the 5.56 (the 308 being almost 100g heavier), does this transfer more energy onto the target or is 1400 ft lb the same thing, regardless of what it is? I'm not that up to date with my physics, but I'm guessing a heavier/larger projectile hitting a target with the same retained energy will transfer more to the target due to momentum?

Someone with some physics degrees chime in here.

 

[Mormegil87]

I don't have a physics degree, sorry. To be honest though, I really think 2760 is a bit slow for a 6.5. I've pushed 140 Bergers into the 2800-2825 range. I may have just had an awesome barrel. I would like to try some of the Flatline offerings in 6.5 just to see where it goes.

That being said I still shoot .308, it's a great practice and hunting caliber and saves me from burning up AI barrels. I always have one.

 

[lash]

I was using roughly book values for the comparison to try and avoid bias. Many are pushing the 6.5 s at 2800-2900. It's pretty typical for field rifle shooting. And you should be able to get 3000-3100 with the Flatlines I hear.

As to the German's question, I think he'd get a deeper discussion on one of the long range hunting forums, since he is really getting into the whole arena of retained mass and energy on target along with tissue damage and wound channel. I don't think it's real world to try and separate the whole into pieces just for discussions sake.

 

[Starbuck]

My 175 is going 2774 (faster than the listed 139g round) so I'm thinking that may put the 308 on top energy wise at least in this comparison. I'll look at JBM and see what it says because target energy matters as much to me as exterior ballistics. With this in mind, I'm starting to dabble with the 185g as well in 308.

Now here's a question as I don't know how the target energy on the target (terminal ballistics wise) is translated from the ft lbs of different projectiles. Fragmenting rounds like the M193 aside as well as assuming its the exact same bullet construction, how does this scenario work as far as listed ft lbs:

175g 308 hits at 1400ft lbs

140g 6.5/260 hits same target at 1400ft lbs

77g 5.56 hits same target at 1400 ft lbs

Since the 308 is 35g heavier and slightly larger than the 6.5 and both are larger and heavier than the 5.56 (the 308 being almost 100g heavier), does this transfer more energy onto the target or is 1400 ft lb the same thing, regardless of what it is? I'm not that up to date with my physics, but I'm guessing a heavier/larger projectile hitting a target with the same retained energy will transfer more to the target due to momentum?

Someone with some physics degrees chime in here.

Hit the Projectile Metrics button in Field Firing Solutions. No physics degree needed.

Linked here is the instructional video:

http://www.screencast.com/t/A6OwmQDHE

 

[A5scott]

Obsolete? Everyone has their opinion, and I'll never get rid of my 308 gassers, and only add to them. Ammo available nearly everywhere, fairly inexpensive. Lots of surplus ammo, bulk ammo, NATO cartridge in 7.62x51, 308 is a very good rifle to have. FN FAL, HK91, SR-25, M-14, so many great rifles in 308 or 7.62x51.
The extended barrel life is another benefit, and a reason enough to have one or 20 in the safe.

My first bolt gun is in 6.5x47 though lol. 2 more months to wait for it.

Scott

 

[308220]

Comparing the old and outdated 308 SMK's against top of the line 6.5 bullets is kind of pointless. I always see ballistic comparisons using 308 SMK's at turtle velocities against 6.5 Bergers cruising along at 2850-2900. Some guys like 308's, some like 6.5's. Neither one makes the other obsolete.

Ill always have a 308. And Ill always have a soft spot for a 6.5-284 Norma.

 

[Greg Langelius *]

This topic comes either 15 years too late, or just a tad early for me. I divested my 308's back around 2005, after being Godsmacked with the .260.

But I recently acquired a Savage 11VT .308 as a big Brother for my 11VT .223, and have made up some 178 ELD-X 308 rounds for early development.

I agree that the 139 velocity above appears slow, my 28" .260 clocks right around 2850 with HDY 140 A-Max. Right now the 308 is awaiting delivery of a nicer Choate stock for serious shooting.

How well these stand out at distance together would be interesting to see in the field. 738ft/lb at 1000 (308 178 ELD-X at 4800ft ASL) vs 844ft/lb at 1000 (260 143 ELD-X same altitude) on paper.

I'm thinking the 11VT is becoming my standard rifle. I prefer factory rifles, and the 11VT has what i consider to be a pretty ideal set of features for my kind of amateur precision shooting; essentially a KD range shooting application using a rest or bipod from a bench.. I am thinking of acquiring one more 11VT 308 and swapping out the factory .308 barrel for 28" 260 L-W drop-in barrel. This would set me up with a brand new factory 308 barrel as a standby replacement for which a matched handload already exists.

Greg

 

[MarinePMI]

[No message]

 

[steve123]

I'm glad someone mentioned this. Definitely doing the .308 a disservice by using an antiquated pedestrian load for comparison purposes. There are new factory options with 185 Juggs, and all kinds of bullet options nowadays to close the gap. I am personally using a 180 flatline with a G1 of .712 at 2888 fps in my 26" .308 (magspeed capture below) and feel like its very competitive to the 6.5s. Yes it does come at a cost disadvantage though, and yes I am aware you can also use solids in the other calibers as well.

I decided to rebarrel in .308 again to take advantage of the long barrel life, and the fact that I could use Flatlines if I need the extra oomph at distance.

I was just telling what bullets those guys used at our match or what the other guys were using that I'd run into. They all certainly could have made a better bullet choice in their 308. I'm not saying 308 is obsolete they all have their place. I have one still but it's not a long range rifle. Obviously for long range there's better choices.

That AZPRC match would start at 300Y but most of the steel was 600Y to 900Y which puts "most" 308 loads at a huge disadvantage compared to the 6's, 6.5's, 7's or big 30's.

Being that regular guys will go to the gun store and buy standard 308 match ammo I consider my comments a great warning for someone serious about long range.

 

[308220]

Well, I'm not a physicist, nor do I play one on TV. Hell, I didn't even stay at a Holiday Inn Express last night, but since no one else has chimed in, I'll hazard a guess.

I believe that weight and momentum have already been baked into the ft/lbs unit of measure. The heavier bullet is traveling slower, but the lighter bullet is traveling faster. The momentum/terminal energy in this case equals out. I believe.

What I think will make a difference is sectional density. The .308 will dump it's energy more quickly, but the higher sectional density of the 6.5 will allow it to penetrate deeper even given equal ft/lbs terminal energy.

But they are both delivering the same ft/lbs of energy on the target (in your example).

I wonder how much more penetration a 6.5 bullet with a SD of .287 has over a 308 bullet with a SD of .268? I bet its every bit of 30 millimeters!

 

[Sierra770]

I still use my .308 to train with. I am running a variety of 175RDF, 178ELD-M and other higher BC bullets than SMKs at velocities higher than factory ammo. I think if you are a skilled handloader with a solid sub .5 MOA rifle, then the .308 can be competitive, but will still have a hard time besting the 6mm-6.5mm guys.

My opinion aside, the article was pretty spot on.

 

[prcomte]

I run old sierra 155 SMKs in my 308. When people ask me what bullet I run I tell them 155 Palma bullet and I get blank looks.

I know that look all to well. I run the same bullet in a lapua palma case.

 

[moosemeat]

In my game, F T/R, 308 is still the king....
While the 6.5x whogivesashit is ballisticly better in every possible way it still makes a smaller hole, smaller splash on steel and less likely to break a ring for score.
I can find FGMM just about anyplace is 308. I can't find hardly and 6.5 loads. My barrel life is ridiculous. Component cost is about a wash depending on brass choice.
If I was allowed to shoot 6.5 in my game I would. Im not so 308 works for most of my needs and i think one awesome rifle that I know well beats 3 ok rifles I shoot sometimes. Knowing my dope and my wind has won me a couple of matches against 6.5 creeds and 6mmBR in open class midrange.

 

[Lowlight]

The article was more in the context of competition shooting, PRS Style stuff. Most shooting disciplines have a dedicated 308 class because it is left in the dirt. We have far more options today than before.

It's just as easy for a guy to buy a good 6.5CM out of the box than to go the 308 route. But with changes in bullets, even that is swinging back to center. You can get factory loaded ammo with better 308 bullets. For reloaders, the options increase even more. Better bullets for sure, but better powder. Used to be the average velocity for the 175 was 2650 to 2725, anything over 2700 was great. Now we can increase that velocity and add a better bullet so the tables can and do balance a bit.

If you shoot by yourself or just a few minor local matches you probably won't see any point to all this. Even if you decided to take a training class, a 308 will serve you well. But say you decide to do the NRL. The 308 will land you don't the list. They are doing a separate class, so you're competing with everything. Clearly, a lose - lose proposition. For anything else, if you do a 308 class, you have to handload and you need speed plus a better BC.

Before the turn to the 6.5, we saw a lot of guys running 155gr bullets. Especially with the AI rifles down at Rifles Only. The 1-12 twist barrels were perfect to run the 155gr bullet in the 2900fps range. But now, I would go 1-10 and run 185s at 2700fps vs the 155. Or run the Nosler RDF Bullets, Warner Tools, etc. I still have and used to run the Lapua 170gr HPS Bullets. They were a FMJ sniper round that went over 2800fps with a BC of .525. Using the Harbinger I beat out a bunch of ballistically better bullets. 2800fps out of a 22" barrel was screaming and they were hammer accurate in my rifles. Still, have a case. Hard to find and pricey but man I loved them.

 

[lte82]

The article was more in the context of competition shooting, PRS Style stuff.

History question for you Frank. There were plenty of CIP / SAAMI registered (and wildcat) cartridges that grossly outperformed the 308 win on the same basic footprint, even 60+ years before the 308 win was ever developed. So, why was the 308 ever the cartridge of choice for PRS style competition when these matches started? For instance, 20 years ago there were plenty of 6 and 6.5mm high bc bullets out there, as David Tubb won at Camp Perry with a 6.5-08 that year shooting 140 smk's well before PRS was a *thing*. Were there rules in the PRS style matches when it started that only allowed 308? Was it just a culture of trying to stay true to military roots? Availability of decent factory ammo maybe?

 

[Lowlight]

Yes it all revolved around the military. We were using 700P, Accuracy International, SAKO TRGs, and not much else. A hot rod rifle was a custom 308, a GAP Rock.

Terry Cross really started down the road with the 6.5. He was shooting variants long before most.

When ASC got popular, because the slow fire nature of it, we were shooting 7WSMs. George used that, even though he was doing outstanding 6.5 rifles including really nice 260 Gas Guns back in the day. The 308 was typical even through a few of us were running other stuff. For like 3 years nobody came close to the GAP Crew who were running 7s, we swept the Top 5 every year with those 7WSMs.

it took a while for other calibers to catch on. One of the things that make it slow is, several of us dabbled in F Class. This was before the addition to F/TR and we saw it as a gear race and nobody like it. If you spent more money and built a Belly Benchrest gun like used in F Class it was not going work because of the alternate position stuff, the movers, the barricades, that was the reason not to hot rod a gun like F Class was doing.

The original Ghost Dancer project was a 260, that was circa 2001 and we bought Savage rifles for it. They used to offer the 10FP in 260REM and that year they discontinued it. They sold SH 5 rifles for $250 each. We shot the Spirit of America F Class match with them vs shooting a SH / Rifles Only Match. So that is where the mindset was.

 

[Upstate43]

I recall seeing a snipers hide article saying that the 308 is obsolete or something of that nature compared to the 6.5 CM. I searched around an wasn't able to find it. Anybody know where it is?

Thanks!

It was an article on the Scout version of Sniper's Hide. I don't know if Frank brought it over to the new site. The basic gist was that 6.5 CM had better ballistics, especially beyond the 500-600 yard mark. However, Frank did make a point of stating that there were newer loads (he mentioned Berger's 185gr Juggernaut) that allowed .308 to narrow the gap a bit. All paraphrasing on my part, and the if you could find the actual article it's well worth your time to read it.

All that said, "obsolete" is a relative term. Obsolete for what?
Informal target shooting? Well if you're 500 yards and in, I don't know how much of an advantage you'll notice going with a 6.5 CM over a .308.
Competition shooting? The 6.5 CM's lower recoil and better wind cheating lends itself to that kind of use. That said, there are still some competitions that cater towards using 'service' cartridges.
Hunting? Depends on what you're hunting. 6.5 CM should be able to take white tail and even black bear-sized animals at certain distances. I think .308 has some energy advantages out to similar distances (as well as having more varied hunting loads) so it might be a better choice, again depending on what you're hunting.

Generally-speaking, the .308 round is nowhere near becoming obsolete. It is still heavily relied upon in military and police communities (a contentious topic among many firearms enthusiasts, but it's hard to argue with the .308's battlefield performance and logistical prevalence). It is an extremely popular hunting round (due to its flexibility and varied hunting loads). And many enthusiasts still use it for recreational shooting. Until the .308 starts to lose its popularity in one or all of those areas, it will remain a very relevant round.

I think on this site, we tend to view and analyze things through the perspective of tactical competitions. The reality is that competition shooters (who are only a tiny fraction of the overall shooting community) have their reasons for using 6.5 CM (and similar cartridges), while other people have their own reasons for using something different (like .308). I've never subscribed to the idea that just because some professional competition shooter is using a certain cartridge or piece of equipment, that means I should be using it as well. Figure out what you want to do and then select the equipment and cartridges that are appropriate for your needs.

 

[Jrb572]

What barrel lengt is good for a 6.5 CM?