Thinking about sticking with .308 vs. 6.5, am I crazy?

Jan 9, 2011
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I should have explained little more in depth. A high bc 6.5 bullet/lighter mass will not rock a steel plate like a lower bc/heavier mass will at long range. I have shot deer at 500-590 yards w the 6.5 and 308. The reaction and terminal damage is always higher w the heavier mass. Sorry I'm going from my life experiences not from a program or a internet warrior LMFAO. You may have experienced diferently
I've experienced no noticeable difference in the two honestly. Other than more hits with a 6.5. We all have opinions and that's fine. You don't need to justify anything to me. You just stated you weren't sure if the ballistics programs took mass into consideration and I was just informing you that they do.
 
Dec 20, 2017
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These threads are about as fun to watch as the 9mm vs 45ACP threads:ROFLMAO:

But seriously though, OP...if you have a shit-pot full of components for a rifle you already have that shoots well enough for you, just stick with it until you run out or burn the barrel up. At that point, as others have said, then you can decide if you want a change of scenery. It's really that simple.
 
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spife7980

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So add up the cost of a die set and 2500 rounds worth of components plus a barrel and GS charges that apply for the 6.5, then do the same with 4000-5000 rounds for the .308.... then divide by the # of rounds, and find your total price per round and decide if the performance is worth the cost to you..
All prices via brownells normal list pricing. Obviously you can find anything on sale at any point in time, I cant really account for that variance. Im sure Im screwing the math up somewhere, yall check it and correct me. Im not going to worry about hazmat or tax etc

140 ELD
33.99/100=34 cents per
H4350
209.99/8/7000=.0037 dollars per grain
42gr*.0037=15.7 cents per round in powder
34+15.7=49.7 cents per shot
Lapua 6.5 brass
124.99/100=1.25 per
300 pieces*1.25=375 bucks
375/2500 shots=15 cents per shot
CCI 200
34.99/1000=3.5 cents per
49.7 from above+15+3.5= 68.2 cents per round
600 per barrel/2500=2.4 cents per round in barrel life
70.6 cents per round in 6.5 barrel life. 70.6*2500= 1765 over all cost to shoot out a 6.5 barrel.


178 eld
34.99/100=35 cents per
Varget
190.99/8/7000=.0034 dollars per grain
44gr*.003415= 15 cents per round in powder
35+15=50 cents per shot
Lapua 308 brass
83.99/100=84 cents per
300 pieces*.84=252 bucks
252/4000 shots=6.3 cents per shot
CCI 200
34.99/1000=3.5 cents per
50 from above+6.3+3.5=59.8 cents per shot
600 per barrel/4000=1.5 cents per
61.3 cents per round in 308 barrel life 61.3*4000=2452 over all cost to shoot out a 308 barrel.



The 6.5 at 70.6 cents per round * 4000 rounds to equal a 308 barrel life would be 2824
2824-2452=372 additional dollars for an equivalent amount of trigger pulling.
~14% more expensive
 
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Apr 27, 2013
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I agree w a FAST 6.5 at extended 1k plus is superior but out to 1k in my experience w fast 155 or 185 jugger making first round hits or shooting tight groups is very doable.. go out and shoot. If you truly believe it is not feel free to meet me at Sheepdog warriors in Catskill NY on a weekend and you can run my GA Precision w my handholds. This started w the 6.5 CM and the 308 win not the fast 6.5/7 w bullets in .700 plus
I agree with you. I like to shoot the 2156 and have no issues with it to 1000. My 308 serves its purpose perfectly.
 

BCX

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Mar 18, 2018
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Life is short spife get out and shoot. Cant put a dollar amount on happiness 6.5 or 30 they all go bang. Buy once cry once
 

BCX

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GM i sent you my load data. USE W CAUTION and work up please..... Every barrel is different
 
Feb 26, 2017
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I love the "if the military uses it it must be good" argument. Only people who haven't been in the military use this argument. We use things not because they are good, but because some senators cousin owns a manufacturing company.
 
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Nov 17, 2011
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I love the "if the military uses it it must be good" argument. Only people who haven't been in the military use this argument. We use things not because they are good, but because some senators cousin owns a manufacturing company.
thats not what i said.....go back and try reading it again when youre reading comprehension gets above a 5th grade level
 
Feb 26, 2017
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thats not what i said.....go back and try reading it again when youre reading comprehension gets above a 5th grade level
Did I even fucking quote you? You need to listen to some Carly Simon. I was making a general observation, don't be a fucking asshat.
 

GM795

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GM i sent you my load data. USE W CAUTION and work up please..... Every barrel is different
I've read it and all I'll say here is, you haven't convinced me….but I’m not looking to be convinced so it’s all good.
 

spife7980

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Life is short spife get out and shoot.
Jesus Christ. See the quote vvv. Pay my rent, fund my 401k, cover my health insurance and buy me a car and I will be happy to ditch my job.
I have a job which prevents me from being out shooting during the week so I might as well maximize my time shooting in the ways that I can.

Cant put a dollar amount on happiness 6.5 or 30 they all go bang. Buy once cry once
You actually, very much so, can. See the above math.

Just because both are guns doesnt mean one is as competitive as another.
 

Ledzep

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Something to consider Spife.. and I edited this into my earlier post...

The 178 eld vs. the 140 eld comes with the 6.5 having a pretty good performance increase.

If you put them closer in performance, using the 185 juggernaut for example, the .308 costs more. The margins are very close and are very variable depending on how you treat your brass etc.
 
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spife7980

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75 ELD
21.49/100=21.49 cents per
8208 XBR
189.99/8/7000=.00339 dollars per grain
22gr*.00339=7.5 cents per round in powder
21.49+7.5=29 cents per shot
Lapua 223 brass
63.99/100=64 cents per
300 pieces*.64=192 bucks
192/4000 shots=4.8 cents per shot
CCI 200
34.99/1000=3.5 cents per
29 from above+4.8+3.5= 37.3 cents per round
600 per barrel/4000=1.5 cents per round in barrel life
38.8 cents per round in 223 barrel life. 38.8*4000= 1552 over all cost to shoot out a 223 barrel.

6.5=2824
308=2452
223=1552

2452-1552=900 more too shoot a 308. Thats a 57% increase to shoot 308 over 223. The following charts show that @1000 yards the 223 will drop 9.8 mils and drift 2.8. The 308 will drop 9.4 and drift 2.4.

So based on some of these arguments that a 308 works well enough and is cheaper too boot than a 6.5 (again, we're not discussing the OPs sunken costs at this point in the thread)... wouldnt the 223 be even more desirable as it both drops and drifts only .4 mils more and is 63% of the price. So if you can live with giving up the performance of the 6.5 over 308 because the cost benefit isnt there is with a 6.5 how can anyone honestly argue for staying with a 308 over 223? And dont tell me because the target will swing ever so slightly more. Just a point to ponder if we are thinking that an increase in performance in inconsequential.


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If we take the cost of a Juggernaut bullet so that there is no trajectory benefit to a 6.5
185 Jugg
58.99/100=59 cents per
That calculated in ends up giving us a price of 3412 to shoot out a 308 barrel.
Thats an increase in cost over a 6.5 of 588 dollars, a 20% upcharge.

So you can spend even more on shooting a 308 to equal the 6.5 or you can save money and be nerfed. Personally I would go for the 6.5 and its litany of benefits at the middle ground in cost. As most would from the get go as has been addressed. We are in this game to hit things after all, not to just pull the trigger. (Sorry I forgot you mentioned that on your earlier posts mcameron, recency bias in the chronological post order lead me to jump in without realizing you had said fresh from the get go you would lean 6.5)

And to address BCX telling me to get out and shoot in spite of having to work: its for these considerations of having to finance this hobby that I end up shooting my 223 most of all :ROFLMAO:


Edit: How in the heck did I let myself get sucked into a 308 vs 6.5 debate?
 

BCX

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Spife its a saying get out and shoot. Trust me i know all about work and financing our hobbies. Work was slow today so i was able to stir the pot today :p
 
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Dec 20, 2017
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thats just the thing.......people would rather spend countless hours jerking off over ballistics tables.......and never actually shoot.


"oh this round is 30% better than this round"

"this round has 20% less recoil than this round"

ect.

percentages dont mean jack shit.

example....

if you have $1.....and i give you another $1......you just increased your money by 100%....sounds impressive...but you still only have 2 fucking dollars.
I was going back through this shit show of a thread (sorry OP, this probably isn't want you were envisioning), and apparently missed this little steaming pile of horseshit the first time around.

I usually don't go out of my way for self-proclaimed assholes, but you sure seem to go out of your way to be a dick just for the sake of being one.

I'm sorry your wife wears the pants and has your testicles on a European mount over the fireplace, which leads you to the internet to attempt reasserting your masculinity and dominance by engaging in keyboard warfare and schoolyard name calling.

Yes, some of us rub a fast one out to data and percentages, and we do so in the same manner we would to memories of your mother and us on that long weekend in Maui - with great fervor, and with copious amounts of lube.

Following your logic, if no one gave a shit about incremental improvements, we'd still all be shooting 45 caliber buffalo rifles.
 
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Nov 17, 2011
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I was going back through this shit show of a thread (sorry OP, this probably isn't want you were envisioning), and apparently missed this little steaming pile of horseshit the first time around.

I usually don't go out of my way for self-proclaimed assholes, but you sure seem to go out of your way to be a dick just for the sake of being one.

I'm sorry your wife wears the pants and has your testicles on a European mount over the fireplace, which leads you to the internet to attempt reasserting your masculinity and dominance by engaging in keyboard warfare and schoolyard name calling.

Yes, some of us rub a fast one out to data and percentages, and we do so in the same manner we would to memories of your mother and us on that long weekend in Maui - with great fervor, and with copious amounts of lube.

Following your logic, if no one gave a shit about incremental improvements, we'd still all be shooting 45 caliber buffalo rifles.
now in your incoherent rambling did you make a point?

or are you just trying to be a badass on the internet so you can get off to it later?.......cuck porn not getting you hard enough anymore?

if you are trying to be an asshole, you are out of your league......so go back to your mothers basement and leave the actual discussion to people who know what the fuck they are talking about.
 
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now in your incoherent rambling did you make a point?
Absolutely...apparently you missed it the first time through, imagine me saying it slower for you this time:

"Following your logic, if no one gave a shit about incremental improvements, we'd still all be shooting 45 caliber buffalo rifles."

Using your own 30% this or 20% that examples, there are a lot of people that 20-30% of whatever it is they're concerned about is absolutely worth it. You obviously don't think it's that big of a deal...bully for you. Just think it's pretty short-sighted to imply someone is an idiot for thinking the difference between a 308 and 6.5 cartridge is appreciable enough to pursue.
 
Nov 17, 2011
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Absolutely...apparently you missed it the first time through, imagine me saying it slower for you this time:

"Following your logic, if no one gave a shit about incremental improvements, we'd still all be shooting 45 caliber buffalo rifles."

Using your own 30% this or 20% that examples, there are a lot of people that 20-30% of whatever it is they're concerned about is absolutely worth it. You obviously don't think it's that big of a deal...bully for you. Just think it's pretty short-sighted to imply someone is an idiot for thinking the difference between a 308 and 6.5 cartridge is appreciable enough to pursue.
sorry, must have missed that in that, i didnt actually bother to read your entire rambling bullshit of a post.

if you actually got out and shot the 2.......i dont give a fuck about tables.......get your ass out on the line and shoot them.......you will see 6.5 is not DRASTICALLY superior to 308.........it is SLIGHTLY superior........

and dont try to bull shit me, because i know you havent.

now ive said this before, if you are buying a new gun....sure, buy a 6.5.......but for someone who already has a rock solid 308.....going through the expense of buying a rifle in 6.5 is not worth it........and yes, of course thats my opinion.....everyones response here is their opinion
 
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Ledzep

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Jun 9, 2009
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The OP isn't buying a new gun if I'm not mistaken. He's at the point where he's ready to replace a worn out barrel and it (the barrel) is going to cost him the same either way.

Again..... The only decision here is whether or not a new set of dies and some new brass is discouraging enough to avoid the universal increase in performance gained (using the same/similar cost/design projectiles) by switching to 6.5 Creedmoor.
 
Dec 20, 2017
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sorry, must have missed that in that, i didnt actually bother to read your entire rambling bullshit of a post.

if you actually got out and shot the 2.......i dont give a fuck about tables.......get your ass out on the line and shoot them.......you will see 6.5 is not DRASTICALLY superior to 308.........it is SLIGHTLY superior........

and dont try to bull shit me, because i know you havent.

now ive said this before, if you are buying a new gun....sure, buy a 6.5.......but for someone who already has a rock solid 308.....going through the expense of buying a rifle in 6.5 is not worth it........and yes, of course thats my opinion.....everyones response here is their opinion
Oh Mylanta...one at a time:

1. Well at least you admitted it. *slow clap*

2. I actually own one of each, and I much prefer my CM. It's no magic bullet (pun most positively intended), but I get more enjoyment out of it than my 308 (there are other reasons I prefer my CM over my 308, but you've already admitted that you don't fully read posts so I should probably keep it brief).

3. We know, we know...you appear to relish in that fact for some reason...?

4. There again, as I've alluded to above, one man's "meh, that's close enough" is another man's "oh that's DEFINITELY better!". If you're not following where I'm extrapolating that from, allow me:

"...there are a lot of people that 20-30% of whatever it is they're concerned about is absolutely worth it."

5. Au contraire, mon frere...see number 2 above. You "know"? :ROFLMAO::ROFLMAO::ROFLMAO:

6. Here's the part where I (**GASP**) agree with you. Since you admittedly don't fully read posts, I can understand how you missed it. As explained in one of my previous posts, if the guy has a boat load of components with a good load and rifle he's comfortable behind, it behooves him to keep on trucking until he's either a) out of components, or b) reached the end of his barrel's life. Then he can decide if he wants to choke the chicken to tables like the rest of us.
 
Jun 8, 2008
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I can't believe this is even a discussion. So ridiculous....

The military only still uses 308 in gas guns. Bolts are all 300WM which will be replaced by Normas soon. The gassers will be replaced by 6.5s soon as well. Its just so hard to get a company to make a working gas gun on an industrial scale, much less in a more unique cartridge. Hell, lots of boutique, niche commercial companies fuck it up all the time. Reed Knight still can't make one in 308.
 
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Sep 1, 2011
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It is fun to watch everyone take a shot at this one. One is not better than the other. It is physics. Do you want more recoil and energy on target or do you want less recoil to follow your shot and not feel beatup after 200+ rounds? Competitive shooters choose smaller calibers because they want less recoil.

99.9% of all shooting is under 1200 yards. It doesn't matter what caliber you choose if you choose a cartridge and bullet combo that maximize the caliber. For the short action not including the Magnums the numbers are pretty straight forward. 7mm is the most underated caliber and will probably be the go to caliber in 5 years after all the 6.5 CM shooters wear the new shine off.

A 24" 22-250 with a 90 at 3000 or a 24" 243 with a 105 at 3000 or a 24" 6.5 CM with a 140 at 2800 or a 24" 308 with a 208 at 2600.

If you know what you are doing then you hit your target more and if you don't then you hit it less. It's not the caliber or the cartridge that is the problem.
 

LRI

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sorry, must have missed that in that, i didnt actually bother to read your entire rambling bullshit of a post.

if you actually got out and shot the 2.......i dont give a fuck about tables.......get your ass out on the line and shoot them.......you will see 6.5 is not DRASTICALLY superior to 308.........it is SLIGHTLY superior........

and dont try to bull shit me, because i know you havent.

now ive said this before, if you are buying a new gun....sure, buy a 6.5.......but for someone who already has a rock solid 308.....going through the expense of buying a rifle in 6.5 is not worth it........and yes, of course thats my opinion.....everyones response here is their opinion
You'd make a much better point with a modicum of politeness and better grammar.
 
Likes: jg6.5
Dec 17, 2017
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It's disheartening when honest questions devolve into a pissing match and objectivity and perspective give way to ad hominem attacks.

I settled on 6.5CM as my first gun and I like it. But if I'd have had access to a 7.62/.308 and already had dies and components and experience with the .308? I'd probably stay with that. I think it depends on what yer shooting and a level of experience and expertise. I like the 6.5 over the .308 because it bucks a little less and shoots a little flatter but I doubt it's a Miracle Caliber. I was making some pretty good shots with my brothers Ruger Precision Rifle in .308.

I just shot the 6.5 better at the same ranges as a complete newbie. YMMV.

VooDoo
 
Sep 16, 2017
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It is fun to watch everyone take a shot at this one. One is not better than the other. It is physics. Do you want more recoil and energy on target or do you want less recoil to follow your shot and not feel beatup after 200+ rounds? Competitive shooters choose smaller calibers because they want less recoil.

99.9% of all shooting is under 1200 yards. It doesn't matter what caliber you choose if you choose a cartridge and bullet combo that maximize the caliber. For the short action not including the Magnums the numbers are pretty straight forward. 7mm is the most underated caliber and will probably be the go to caliber in 5 years after all the 6.5 CM shooters wear the new shine off.

A 24" 22-250 with a 90 at 3000 or a 24" 243 with a 105 at 3000 or a 24" 6.5 CM with a 140 at 2800 or a 24" 308 with a 208 at 2600.

If you know what you are doing then you hit your target more and if you don't then you hit it less. It's not the caliber or the cartridge that is the problem.
Your logic is mind-boggling.
 
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Sheldon N

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A 24" 22-250 with a 90 at 3000 or a 24" 243 with a 105 at 3000 or a 24" 6.5 CM with a 140 at 2800 or a 24" 308 with a 208 at 2600.
I like your point. A couple caveats that make it not quite so simple though.

2600fps with a 208gr bullet from a 24" 308 is possible but it's not an apples to apples comparison with those other caliber/velocity combos. 2500fps is more realistic if you match internal case pressures. 308 just is a bit too small of a case to get the really heavy for caliber bullets up to speed. The difference becomes even more pronouced if you were to choose 110 or 115gr 6mms and 230gr 30 cal.

At 2500fps you're giving up a couple tenths of wind, plus you go transonic inside of 1000 yards, about 150 yards sooner than the others. You're also more vulnerable to ranging errors in target distance.

Finally, a heavy bullet from a 308 is a lot more demanding to shoot well. You have to be on your A-game with recoil management where as a smaller caliber is more forgiving. Not making excuses for poor shooting, but the net result is that if you handed out a dozen rifles of each and had average shooters fire a bunch of rounds you'd see higher hit percentages with the smaller calibers even if the ballistics were the same. I suppose you can call a 6mm a crutch and a 308 a man's caliber, but the net effect is the same.

I've competed and shot a bunch with both 308 and 6mm, and I can say that ballistics aside I shoot better with the 6mm, especially in positions other than prone.
 
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Sep 1, 2011
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I like your point. A couple caveats that make it not quite so simple though.

2600fps with a 208gr bullet from a 24" 308 is possible but it's not an apples to apples comparison with those other caliber/velocity combos. 2500fps is more realistic if you match internal case pressures. 308 just is a bit too small of a case to get the really heavy for caliber bullets up to speed. The difference becomes even more pronouced if you were to choose 110 or 115gr 6mms and 230gr 30 cal.

At 2500fps you're giving up a couple tenths of wind, plus you go transonic inside of 1000 yards, about 150 yards sooner than the others. You're also more vulnerable to ranging errors in target distance.

Finally, a heavy bullet from a 308 is a lot more demanding to shoot well. You have to be on your A-game with recoil management where as a smaller caliber is more forgiving. Not making excuses for poor shooting, but the net result is that if you handed out a dozen rifles of each and had average shooters fire a bunch of rounds you'd see higher hit percentages with the smaller calibers even if the ballistics were the same. I suppose you can call a 6mm a crutch and a 308 a man's caliber, but the net effect is the same.

I've competed and shot a bunch with both 308 and 6mm, and I can say that ballistics aside I shoot better with the 6mm, especially in positions other than prone.

I agree that the main reason people don't shoot a 308 for competition is recoil with 200+ grain bullets is very difficult to manage effectively all day long in awkward firing positions plus it beats you up after several hundred rounds compared to the under 140s. Ranging a target is typically not the issue it is wind so the BC numbers of the larger calibers typically make up for the lack of velocity and the smaller calibers make up for lower BC with velocity. I am just quoting general velocities that I typically see and have personally used. I get over 2600 from my 24" 308 with 208s and I get a little over 2800 with 140s in my 6.5 CM and over 3000 with 105s in my 243. I have a 22-250 fast twist barrel on order just to experiment with the 90s at distance.

i just do not understand why everyone gets so up tight about 6.5 CM vs 308. If you run both in their best configuration the differences are truly negligible. The OP was trying to compare a 155 308 to a 140 6.5 and that is just not a real comparison. If you are going to shoot 155s from a 308 then just get a 6.5 already and be happy with it. People try to throw the same argument for 178s in 308 vs the 140s in 6.5 and it still is not an apples to apples comparison. If you are going to compare a cartridge then be honest. The 6.5 definitely has advantages but wind is not one of them. RECOIL and DROP without a doubt but that is not why people typically miss the shot. WIND

If everyone only had the 1st Shot then they would not pick a 6.5 CM they would pick a larger faster caliber/cartridge combo like a 7mm SAUM or larger but in today's shooting competitions they shoot hundreds of rounds and must follow up rapidly and that means they need less recoil and cheap factory match ammo. 6.5mm and 6mm are a great balance for that. Way better than the 308 that is under powered for the caliber but still a very capable round if used in a max effective configuration.
 
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Sheldon N

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Ranging a target is typically not the issue it is wind so the BC numbers of the larger calibers typically make up for the lack of velocity and the smaller calibers make up for lower BC with velocity.
I dunno, lots of the matches I've been to have had incorrect ranges in the course of fire match book. Two weeks ago at a PRS ELR match our entire squad spent 15 minutes debating whether a target was at 840 or 940 yards because of the way it was placed on a knoll with a ridge behind it. And this was with a $10k vectronix on a tripod and some of the best shooters in the country in our squad. There were steak dinner bets made and it wasn't until the second day that we had the correct range nailed down. And a little over a month ago we had a match where weather conditions made ranging targets extremely difficult. Everything was unknown distance, we shot the match anyway, we ranged targets when there were breaks in the rain, and we shared dope on what we were getting hits with. Huge disadvantage to be shooting a 308 in that situation, even though most everything was inside of 700 yards.

Other issue to consider with range is that the slow 308 is going to have roughly double the vertical dispersion of the faster 6mm out at the farther distances, assuming equal SD/ES. That makes it more vulnerable to missing because of ranging errors, updrafts/downdrafts on a hillside, etc. We see a fair number of targets that are animal shapes, maybe 2.5-3MOA wide but only 1 MOA tall. You've got to have your range and vertical dialed in solid when shooting those targets even though you've got a cushion on the wind due to target width.

I am just quoting general velocities that I typically see and have personally used. I get over 2600 from my 24" 308 with 208s and I get a little over 2800 with 140s in my 6.5 CM and over 3000 with 105s in my 243.
Not saying that your 308 vs 243 velocities aren't possible, just that they aren't equivalent. You can also make a 243 with a 105 go 3200 fps if you want. If you run heavies in a 308 it can get much closer to a 6 or 6.5, but it's not quite a level playing field ballistically. And the 308 is going to be harder to shoot well.

Not hating on 308, I spent the whole 2016/17 match season competing with one including using heavier bullets. Just being realistic about what you give up when you choose to shoot it.
 

Ledzep

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You can get 308 to match wind and elevation goes through the roof. Or you can get it to be comparable in elevation and windage falls to pot (relatively). You can't match both without fancy solids.

A 147 or 155 6.5 beats a 208 .308....

You can't get around it. For the same BC, the 6.5 is faster. You can get higher BC 308, but you have to go 215-240gr where I'm pretty sure muzzle velocity holds you back on supersonic range, elevation, etc.
 
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Sheldon N

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One other minor sidebar difference between a slow/heavy 308 and a faster 6mm.... The more you have to dial elevation, the more critical it becomes to hold the gun dead nuts level for every shot. If you tilt the rifle a couple degrees that's going to cause you to miss low left or low right. That miss becomes larger and larger the more elevation is dialed into the scope. The 308 is more susceptible to these small shooter errors than the 6mm because the 6mm has to dial way less elevation travel.

Probably falls into the broader category of "the 308 is harder to shoot well and 6/6.5mm's are more forgiving".
 
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Sep 6, 2006
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Great argument with lots of data. Thank you for the contribution!
It’s been layed out so many times in this thread. You can shoot heavier and heavier bullets in your .308 with hot loads, but you’re moving in the wrong direction. The 6.5’s are easier to shoot and in most cases a significant ballistic advantage. I think they call that “having your cake and eating it too”.

Are 6.5’s magic, no! Are they a quantifiable performance increase, very obviously, yes!
 
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I
One other minor sidebar difference between a slow/heavy 308 and a faster 6mm.... The more you have to dial elevation, the more critical it becomes to hold the gun dead nuts level for every shot. If you tilt the rifle a couple degrees that's going to cause you to miss low left or low right. That miss becomes larger and larger the more elevation is dialed into the scope. The 308 is more susceptible to these small shooter errors than the 6mm because the 6mm has to dial way less elevation travel.

Probably falls into the broader category of "the 308 is harder to shoot well and 6/6.5mm's are more forgiving".

I agree completely. The 6.5 CM is a better balance of caliber and cartridge for competitive shooting like it was designed. Light recoil with a good BC and cheap factory match ammo.

308 is under powered for the caliber but still a very capable long range round when paired with a high BC bullet even at 2600. I was simply trying to get people to look at the ballistic realities that balance caliber and cartridge. If the OP was going to be a competitive shooter for a living then he needs every small advantage possible otherwise just maximize what you have and shoot as much as possible so you know your setup.
 
Likes: Sheldon N

GM795

The Outlier
Apr 3, 2017
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So we end up pretty much where anyone with half an understanding of ballistics already new we were going to end up –

Ballistically, the 6.5 beats the .308.
So, if your main goal is to hit the target every time with as large a margin for error as you can get then go with the 6.5.

On the other hand, the .308 demands more of the shooter for the same outcome, your fundamentals and wind reading/call need to be on point every time you pull the trigger.
So, if you relish a challenge and enjoy overcoming difficult conditions then the .308 is for you.

And no, I’m not saying the 6.5 is an actual laser gun that only requires you point and shoot to make the hit, I’m just making a comparison between the two.
 
Sep 1, 2011
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Rockwall, TX
So we end up pretty much where anyone with half an understanding of ballistics already new we were going to end up –

Ballistically, the 6.5 beats the .308.
So, if your main goal is to hit the target every time with as large a margin for error as you can get then go with the 6.5.

On the other hand, the .308 demands more of the shooter for the same outcome, your fundamentals and wind reading/call need to be on point every time you pull the trigger.
So, if you relish a challenge and enjoy overcoming difficult conditions then the .308 is for you.

And no, I’m not saying the 6.5 is an actual laser gun that only requires you point and shoot to make the hit, I’m just making a comparison between the two.

Yes. If you want to increase your overall possible precision by about 8% from 900 to 1500 yards then the 6.5 CM is the gun for you. If you already have a 308 and are not shooting in rifle competitions that require a low recoil rifle or you need energy on a target for hunting etc. then I would just stick with 308 and maximize it and shoot it well.




6.5 CM - 147 ELDM - 2800 FPS - 1 MOA Target @ 1200 Yards
1521926643427.png

308 WIN - 208 ELDM - 2600 FPS - 1 MOA Target @ 1200 Yards
1521926737361.png
 
Sep 1, 2011
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Rockwall, TX
I believe your numbers show a 25% improvement, not an 8% improvement. 25% more hits is not what I would call being anywhere near equivalent.

They show an 8% increase in hit probability but you can market it however you wish. Like if your gun only hit the target 1% of the time and I had a gun that hit it 2% of the time then my gun 100% better than yours at shooting yet both of us are actually awful. I like to stick to actual numbers and not make relative statements of improvement.

The difference between the two is only 3% at 700 yards and 0% under 700 yards so it really is a situation where you need to consider the cost of changing cartridges and also the pros and cons. I am just trying to help with data and analysis so don't shoot the messenger. Obviously, there are many short action cartridges that smoke the 6.5 CM too.

Also, most people shoot factory 140 ammo at 2715 so I was just trying to make a fair analysis of maximizing each cartridge.
 
Sep 1, 2011
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Rockwall, TX
26" - 7mm SAUM - 180 ELDM - 2900 - 1 MOA Target @ 1200
1521931645967.png

In my opinion this is the best cartridge/caliber combo out there that you would actually want to shoot on a regular basis. It will be my next build. The shooter that can learn to manage the recoil of this round would have a huge advantage over the field and also have a great hunting round as well with great energy at range.
 
Sep 6, 2006
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So what you’re saying is there’s simply no amount of data that will convince you that the 6.5 is better than the 308.....


The 208 eld load, by the numbers, recoils with 50% more energy that a 140/6.5 load. Your saum, about 90% more.
 
Jan 9, 2011
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Cheapmoa I appreciate your analytical approach, as this is how I approach these questions as well. I think where I differ from you is in answering the question: how much improvement is significant enough? To me, a 25% improvement using my 6.5 Creedmoor standard 140 not-super-hot hand loads over trying to push a 208 eldm in a 308 is very significant! And the 100% increase over a 155 308 even more so.

I agree though a 7 saum is a very tempting cartridge that I will look at for a hunting build in the future to weigh against the 6.5 saum for my specific purposes.
 
Sep 1, 2011
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Rockwall, TX
So what you’re saying is there’s simply no amount of data that will convince you that the 6.5 is better than the 308.....


The 208 eld load, by the numbers, recoils with 50% more energy that a 140/6.5 load. Your saum, about 90% more.

I don't understand your comment. I never said that the 308 was better or worse. I just said that you really need to look at what you actually gain and if that gain is worth the cost. They each have their respective place in the shooting universe. I was trying to help the OP see that the 155 is the worst of both worlds. Either get a 6.5 and shoot 140s or keep your 308 and shoot 200s.

I love my 6.5 and my 308 and every other stick that makes noise.

I am going to do a more in depth analysis on a separate post. Let's find the highest Hit Probability in a short action.
 

steve123

Lt. Colonel
Mar 16, 2008
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Flagstaff, AZ
I don't understand your comment. I never said that the 308 was better or worse. I just said that you really need to look at what you actually gain and if that gain is worth the cost. They each have their respective place in the shooting universe. I was trying to help the OP see that the 155 is the worst of both worlds. Either get a 6.5 and shoot 140s or keep your 308 and shoot 200s.

I love my 6.5 and my 308 and every other stick that makes noise.

I am going to do a more in depth analysis on a separate post. Let's find the highest Hit Probability in a short action.
It's probably going to be a 6.5-4s. People load it down to 55,000 psi to promote barrel life but it can be cranked up. A 7.5 twist and 147's at 3200 fps???should be a killer combo.

In my long action, throated slightly longer with a 29", but still loaded with a medium load, 140 hybrids were going 3275 fps. I had to slow the load down to 3175 because the hybrids were blowing up at the higher velocity.