For shooting? Well in that case...
6.5 Creedmoor vs 308 Winchester
- Thread starter 46490
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I think one think has also been overlooked. In what type of setting are these being shot? F-Class? Sling? Off a bipod on your friend's land? One major thing to consider is the creedmoor is going to beat you up significantly less over a string of fire, especially if you're shooting heavies in the 308.
That's not as crazy as I've seen some posts for certain cartridges and velocities. I make 2880 with 168s and think that's fast. 2750 with 185s was also fast. These were accuracy velocities. I'm sure I could have gone higher but loss of accuracy always seems to happen for me at the very highest velocities.
Guys are getting some serious velocities with the Creedsters and 153gr bullets by the read of this
The UK 'Match Rifle' people reportedly use Reload Swiss RS60 (Alliant Re17 in a different bottle) with >200gn bullets. This is an unusual discipline that predates F/TR literally by decades. It's 308 Win only these days, max 5.5lb barrel weight, any sights, and although a front-rest or support is allowed the shooter's hand must still hold the forend between it and the rest / no rear support is allowed other than the shoulder. Matches are multi-stage, usually 2+15 at 1,000, 1,100, and 1,200 yards on the standard 2-MOA 5-ring / 1-MOA V-Bull 1,000 yard Fullbore target. It can go out to longer ranges - 1,500 yards in a range in New South Wales, Australia.
Throats are optimised for the very long bullets, 32-inch or more barrel lengths are employed, small primer brass used these days and some serious pressures are run. The discipline has long been known for generating MVs / MEs that other 308 shooters find hard to swallow and/or claim must be dangerous. As a result, the relatively few competitors tend to be rather reticent about their loads. However, pairs shooting is the norm as in UK TR and F/TR, so the barrel heat issue that would affect these practices in US and Australian F/TR with string shooting isn't as big an issue even with the thinner / lighter barrel from the 5.5lb rule. In the UK at any rate, much less so Canada and Australia, high ambient temperatures / large changes isn't an issue so RS60/Re17 is more practical. Competitors are obsessed with their long-range elevations to keep them within the five-ring; many of the key matches are team shoots with expert wind-coaching.
So, I don't find @Ray123 's claims hard to accept. As you say though Ned, such loads are likely impractical for use in F/TR. Actually, here in the UK, some very hot loads were used in F/TR with 155s at one time. some of which were up at the 3,500 ft/lb level. They appeared with the arrival of Lapua SP brass and used a newly available Reload Swiss powder RS40, allegedly the canister version of the powder used in RUAG's factory Swiss military GP90 cartridge, its equivalent to 5.56 M855. Even in our cool climate lacking large temperature variations and with pairs shooting, these combinations turned out to be too inconsistent over a competition season, were barrel-killers, and more than a few people retired from matches when such loads 'inexplicably' went over-pressure and started blowing primers. Knowing too what 'warm' 185/200gn small primer brass F/TR loads powered by Viht N150 do to barrel life, I'd imagine the hot MR and other RS60 loads will be even worse.
At 600 yards with the same charge as the 168 smk the 169 smk shoots 1.5 moa higher.
Most of the bullets in the advanced ballistics bullet library book see a significant change in their drag function around 15-1600 fps. That velocity range correlates strongly with my experience of the beginning of noticeable performance decay. My 308 started to lose hit percentage past 800 yards. My creedmoor starts to get iffy at my max range available of 1200. Both of those observed performance degradation points are right around that 1500 fps range. These are both with eldm bullets so it may be bullet design specific. But I now use that 1500 fps as a design floor when making new rifles. I don't have a range long enough to stretch my 7saum and win mag to test that theory with the sierras and bergers i throw in them.
I think this was the primary benefit of tipped bullets. They close up that meplat and improve bc consistency (compared to otm bullets from the same manufacture). They remove the need to sort by nose length.
True. In my opinion its much cheaper to get impressive ballistics out of a 6.5 creedmoor. 308 can match it but it takes specialized equipment.
Lapua and peterson 308 can fit about 53.7 grains of staball 6.5 full to the top. 51ish grains would probably be at the bottom of the neck. 30-06 hits 59-60k psi at around 53 grains of staball with a 200. So out of a smaller 308 case a high 40s-51 grain charge would likely reach good pressure (60-70k) behind a 200 grain pill if the throat was long and leade angle low to facilitate this.
Sierras load data has their 200 seated at 3.15" going 2550-2600 out of a 24" with 4350 class powders at 48 grains. 6 inches more barrel adds about 150fps. We're now at 2700-2750 with 4350 class. Add 2 more grains of a double base ball powder at the slowest burning end of that 4350 class and I bet you can find that last 100-150fps without extreme danger with a purpose built rifle.
300 wsm can do 3100+ fps out of a 30" with a long loaded 200 grain pill. So its not as crazy as it sounds.
You're definitely off the edge of the map though. So its not something I suggest just anyone do.
Sierras load data has their 200 seated at 3.15" going 2550-2600 out of a 24" with 4350 class powders at 48 grains. 6 inches more barrel adds about 150fps. We're now at 2700-2750 with 4350 class. Add 2 more grains of a double base ball powder at the slowest burning end of that 4350 class and I bet you can find that last 100-150fps without extreme danger with a purpose built rifle.
300 wsm can do 3100+ fps out of a 30" with a long loaded 200 grain pill. So its not as crazy as it sounds.
You're definitely off the edge of the map though. So its not something I suggest just anyone do.
If that's repeatable in all firearms shooting the 169 vs 168, I'd say that's decent progress by the company making a one grain heavier Match King bullet in the same caliber and design. My calculator shows around .75 difference at 600
Nope, I couldn't do it with Varget either. I mentioned the powders used, many more were tried but failed, and some of the load data stated, in Accurate shooter...I fired these loads in a rifle chambered and throated for this specific bullet to get max performance, like your long OAL. The pressures are on the high side, but have never blown a primer, even tried it in LC brass... but Lapua brass LR or SR both work, LR tends to get slightly higher velocities. This is a backed off load slightly was just under 2900 fps with the 200... and accuracy and single diget S/D were good at 2856 fps for my rifle only.
I hesitate to throw load data because, of chamber and throat differences, which means pressure differences... Just letting people know what is possible with the 308 and if any of it is right for their application...the brass has been reloaded 4 times...primer pockets still tight. This bullet requires a 9 twist, and it shoots good in my 9 twist light rifle...but excellent in the 8 twist where I have more flexibility with heavy bullets including the 230 Atip at 2620 fps...but that load isn't as accurate as the 225 ELDM, running at just under 2600 fps 5 shots in the .3s very low S/D in the 8 twist. I was going to try 250 Atip to see if I could get 2500 fps, but I'd have to increase the throat length to get optimum results, ruining the barrel for the 200s, which is where it's at with my barrel.
The 250 Atips ain't off the table but they are expensive, and not throating the barrel to a 3.4" COAL for 250 gr would leave performance on the table, but still feed out of the magazine. The Berger 200.2 and the 200 gr SMK ain't the same animal...the SMK is much more sleeker, (aerodynamic) longer requiring a 9 twist, with less bearing surface, so you have a longer COAL add a little more powder equals a little faster, bullet.
The Berger was accurate at 100, depending on the powder charge, but the SMK was too and sometimes beat it, hard to tell the difference but it has probably more to do with the shooter in this case. I went with the SMK, for my general purpose long range 308 load...so far. But the 230, and 225 grainers especially are showing promise, not sure if there is an advantage in my rifle yet.
None of this may be your cup of tea, or you may hate the 308, just turn the page.
But for those looking for some extra performance, it's possible. The components you choose make a difference, it takes a lot of experimentation, to see if any of it is right for you, be it competition, hunting, or long range plinking.
Nope, I don't have Quickload, and never heard of the other internal ballistics program.
Impressive.
Let the target, brass and crony show what's really possible.
Have you explored in similar depth what's possible with the lighter projectiles in the 08 ?
Nothing lighter than 155 for speed, they were going 3100, and 3150 fps when it was warm... in a 12 twist 27" barrel, but accuracy was inconsistent with the tipped MK, 3 in one hole two in another, was to common, but didn't mess with it much...like try a few different 155s. My go to 155 load was like everyone else it seems cause it worked for many years, 2975 to 3030 fps in different barrels. Shoot 15 to 20 thousand ya start to get a feel for the 155s, they worked for me all the way to 1400 yds, back before LR shooting became the rage.
Working on 18" 308 AR 10, just milled the reciever and barrel extension to feed 2.940" COAL, and modified the feed ramps and the magazine. Also working up accuracy loads with cheap LC brass and cheap bullets...just for plinking fun...with 1000 primed & ready to load LC cases. This is my 2nd 18" barrel and almost new Proof, and already shooting some good cheap bullet loads. Also abusing it with the same 200, 208, and 225 heavy loads.
Fast is the 17 Remington over 4800 to 4900 fps with a couple of powders and Hornadys 15.5 gr copper bullet.
I'm curious Ray as to how many rounds that you are able to get out of the .308 Proof barrel, before accuracy degradation?
The short answer 308 barrels are good for usually 8000 rds of shooting according to my expectations. I don't do organized competition anymore quit along time ago, and the local gun club after 10 yrs. They offered nothing I was interested in....plus they were always busy and full of events, on weekends, and the longest range was about 300 yds. So I had to go into the mountains to shoot cause they were busy with events, and no long range..so I quit.
Always subscribed to Precision Shooting mag, and the Varmint Hunters Club member, was more my style.
We were shooting ground squirrels, rock chucks, and sage rat out to 1000yds and beyond. The record was held with a 308 at 2200 yds. Studied the USMC sniper manual, Vietnam eara snipers opinions, Precision Shooting, and Varmint Hunters. Then came up with my own shooting style that worked for me. Never fired shots below 800 yards for years except to check 100 yard accuracy. Travel light when it came to gear...gave up on wind meters, used a Leica ranger finder, a 308, match load 155 Lapua loaded on a Dillon progressive and Varget $112 for 8 lbs. And a Leupold MK 4 10X USMC scope , mil with MOA turrents....ya had to convert mils to MOA. I read the wind by feel anything inside a 2 mil wind was fairly easy. I kept records in those days...I don't now.
Example 8/27/05 6900 rds on barrel 3 shots 1000 yds into 2.422" group.
8/28/05 100 yd accuracy test 4, 3 shot groups
7000 rds on barrel averaged .239"
8/29/04 1400 yds hit a pop can 1st shot
3 shots at 1400 4.25" 5 shots at 1400 7.625"
Used Schilen ultra match barrels, in those days, cause Tony Boyer used em in benchrest according to PS mag...lol. And Jewell triggers set to 2 to 4 oz. No heavy triggers, shoot fast, within 5 seconds after the rd loaded it should be fired, cause the wind will change and your barrel will likely be very hot. Wind change and heat waves off the barrel are the only things that stop you, when you are on.
Today I don't keep records of round count, and don't shoot near as much LR, cause I've already been there and done that, with alot less sophisticated gear and a 308 Win. And I won't buy a Proof carbon fiber barrel, ...just the Stainless steel for me, no fluting, if it ain't heavy it ain't right, then if it shoots, shoot the hell out if it..."saving the barrel"..for what? It's like sitting there admiring my basketball instead of shooting it...nice basketball, but I can't hit nothing with it.
Thanks Ray for that information. I have an MRAD and am working with a gunsmith on a new 308 barrel. Does Proof make just plan old vanilla s.s. barrels? I'm not a fan of the carbon fiber one that they have for MRAD, but finding a barrel conversion kit for the MRAD is very difficult these days.
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