6.5 Creedmoor

[The Badger]

Can anyone advise on the ideal barrel length for a 6.5 Creedmoor. I wish to be able to shoot out to 1000m. I wish to rebarrel a 308. Will I need a 32in tube?

Thanks in advance

Badger

[Andrew]

I have a 20 inch Tikka and I shoot at 1000 with it. Twenty two/ twenty four might be better. I think 32 inches is excessive.~Andrew

[VarmLR]

To benefit from the BC advantage of the slippery bullets, mega-velocities are not needed.  To avoid running high pressures to get, say, a 140 pill to 2800fps, you're best looking for a 24 to 26 inch barrel.  You'll easily get out to 1250 yards with a 24 inch barrel without running too hot.  I don't understand why so many are being sold with 22 or even 20 inch barrels.

[Big Al]

12 hours ago, The Badger said:

Can anyone advise on the ideal barrel length for a 6.5 Creedmoor. I wish to be able to shoot out to 1000m. I wish to rebarrel a 308. Will I need a 32in tube?

Thanks in advance

Badger

You dont say in what context you want to shoot to 1000yds Badger?

As Varm says, a 140gr bullet at 2800fps is well capable of being competitive in to benchrest standards at 1000yds, this would be from a 28" barrel most of the time. A 32" barrel will cost you more money and depending on the rifle builder you choose it might take them some time to get a 33" blank to use.

If your looking to eek out every drop of BC and speed then a 32" wont harm but is seldom needed. As things stand Ive not seen enough evidence to suggest a 6.5 Creedmoor offers the most accurate solution though, the 6.5x47 on the other hand has more than proven itself.

[gbal]

If you wish to shoot  informally/for fun at 1000y with the 6.5 CReedmoor, fine-a barrel longer than 24/26 inches might offer little positive,and some inconvenience (and note Big Al's smithing point).

If you are a bit more serious and want to shoot reasonably competitively at 1000y with your rifle,then we can be a bit more specific. There are three main issues:

!) the intrinsic precision of the rifle (varies by cartridge,and by individual barrel)

2) intrinsic precision of the ammo (eg vertical dispersion sub 1/2 moa at 1000y )

3) ballistic desiderata of the cartridfge,which specified below.

Though now outclassed by the hotter 7mms,the 6.5x284 cartridge enjoyed a good run of competitive success,so let's use that ,as it's also a 6.5 calibre: wind drift is acknowledged the major consideration for good 1000y cartridges,so the 'benchmark specs' of the 6.5x284 give 70" drift in a 10 mph wind,with the popular 142 SMK bullet,at 2950 MV,and BC .565 (G1-and in the 2000-2850 velocity range- remaining velocity at 1000y will be more like 1300fps).

So,those specs are what any 6,5 cartridge has to produce to achieve parity with the no longer top cartridge,but still a decent one. The specific combination can vary a bit-eg a better BC can compensate for a corresponding lower MV.

The final important component/factor is 'accuracy', as BIg Al also raises. I'd prefer 'intrinsic precision' of the carridge design (keeping accuracy for what the shooter contributes with his firing solution and skill,unless ease of shooting fast is added-as indeed it currently often is-hence the 6mm Dasher class) but the concept is clear enough-some cartridges are just a tad better in keeping small groups than others (6PPC at 100y is the clearest example). There may not be a lot in it for the various 6.5 1000y contenders,that meet the above BC/MV criteria,and clear data ,like consistent competition successes at 1000y,over the other contenders,don't yet exist,especially under UK conditions.Add in all the other factors,including individual barrel variation-unknowable in advance between the premium makes.

   SImples-anything less  ballistically efficient than a 142 g BC .565 @2950 MV  package in 6.5 calibre,will reduce competitiveness at 1000y- Those specs will not give parity with the best current 7mms (or Dashers etc on benign days-maybe).But for a 6.5,that's where competitiveness begins.

gbal

 

 

[Vortex]

I’m using a 28 inch in 6.5 creedmoor tho I’m using 123gr running at 2970 ish FPS I could push it more but don’t need to and don’t want to push the barrel any more than I have to. 

Its great to 1000 with only 27.5 min of elevation and last time I shot about 5.5 mins windage at that range in a mild but unpredictable wind. 

going to try the heavier pills but I’ve got 750 123gr bullets to go through first. 

 

 

 

[baldie]

I've built many, many creedmoors, but only remember one with a 32" Krieger. I built it for a friend who is a very successful Diggle shooter. He shoots a lot and shot it out within a couple of years. I then re barrelled it with a bartlein. Both were the same twist and he ran the same loads through it. The new barrel was a 28" one, and it shot faster than the 32 did.

Could be different barrels and possibly bore size, but I've always had a sneaking suspicion that the creedmoor doesn't need an overly long tube.

I run a 20" Bartlien on my AX and have used it at 1000 successfully . I built it as a CSR gun and its main distance was up to 600 yards though. I wanted the portability more than speeds etc.

Personally, I think 26", 28" if portability is no problem, but anything more doesn't gain much.

I remember a good experiment which is still floating around, where some guys started off with a 28" barrel, and kept chopping it down, an inch at time [ creedmoor ]. It was losing on average, 14 ifs per inch, until it hit 19 "....where it dropped off a cliff.

Its a very balanced cartridge, and works well at all lengths.

[VarmLR]

There's an argument that once past 28" in Creedmoor, velocity starts dropping off, and that it's pointless in making Creed' barrels any longer than that as once past that length, more is lost to barrel friction than is gained from the effects of the remaining charge.  That's an assumption though as I've yet so see evidence with differing powders and loads on ther same bullet.  I have only seen one set of data derived from a shot-out barrel that was progressively cut down, and with Sierra Matchkings (142gr) optimum velocities were achieved with a 24 inch barrel, and even when the barrel was cut down to 16 inches, it still out-shot a .308 shooting 175gr smks at 1000 yards.

The article is here:  https://rifleshooter.com/2016/02/6-5-creedmoor-effect-of-barrel-length-on-velocity-cutting-up-a-creedmoor/

I think that this might be the one that you refer to Baldie?

For most club (non competitive) shooters, it probably doesn't matter what length Creed' you choose.  They're all shooters at distance.

[Andrew]

53 minutes ago, baldie said:

I remember a good experiment which is still floating around, where some guys started off with a 28" barrel, and kept chopping it down, an inch at time [ creedmoor ]. It was losing on average, 14 ifs per inch, until it hit 19 "....where it dropped off a cliff.

Its a very balanced cartridge, and works well at all lengths.

I have read this one as well. That's why I don't fret over my 20" tube.~Andrew

[Cienfuegos]

From 24 "it has enough range, with the necessary energy, if there is no transport problem, the 26" guarantee success ... But with 28 "I have a very accurate node at 2900 ft. And it has gained some 300 WSM Always a bullet of 139

[gyr]

Anyone shooting a 24” ? It seems there would be a loss of some 50 fps compared to a 26”’, but you gain maneuverability.

[Pat Allen]

I shoot a 24 inch in 6.5 CM and it holds 4inch at 1000 yds with 140 g ELD’s doing around 2650fps . So I’m happy with that and good barrel life . 

[One on top of two]

☝️

As above 

[gyr]

Thanks for the replies¡