260 vs. 6.5 x 55

[adriandavidb]

Hi

 

This post could have equally gone in any of the other topics, but I had to pick one so here goes . . .

 

I think I may be about to resurrect a topic that's been done to death already, so advance apologies to those stifling yawns!

 

I've heard from several sources that the .260 calibre, based on a necked down .308, or necked-up 243, is a great long range calibre in that trajectory and down-range ballistics are quite similar to the 300 Winchester Magnum. This makes it of potential interest for distances at which.308 starts to loose accuracy.

 

Owing to it's parent cartridge, the .260 is useful because it shares the same bolt face with .308, which gives options for producing a .260 by simply swapping-out a barrel.

 

However, the old 'Swedish' 6.5 x 55 is effectively the same calibre, but with slightly higher cartridge capacity, so presumably shares the ballistic advantages of the .260, if not improving about them . . .

 

I'd very much appreciate some advice on which way to go? I'm guessing the bolt face diameter of the 6.5 x 55 makes it less flexible in terms using a .308/.243 doner action, but is it?

 

Thanks

[bradders]

One thing not to overlook is that the Swede requires a long action in comparison to the .260

[adriandavidb]

Good point; thinking of a T3, so having a cartridge that makes the most of Tikka's 'one size fits all' action would be fine. Thanks for pointing that out though.

[gbal]

Any of the three current 6.5s (260,6.5x47 lapua,6.5 Creedmore) offer considerable longer range advantages over the 308 W in any 'shootable' configuration-if you can handle the 308 with 220 bullets @2650 you will beballistically up with the better cartridges-check you teeth-recoil is considerable.The 6.5 need a 140 bullet @2950 to be bal park (allwith very good BCs of course)

The trio of 6.5s mentioned are stretched to reach that...the 6.5x55 Swedish achieves it in Ackley Improved ,and might be the best choice on pureballistics of the four so far. But none can compete with the current hot 7mms.

 

 

There is no way that the 260 can approach the 300 win mag-that is in a different league-and has been quite popular for long range shooting (I mean 1000Y). A brief look at basic ballistics confirms:10mph wind:

 

260 140g@2800 Nosler BC .49 drop/drift with 200 zero drop/drift at 600y is 76/28" 1000y 332/93

 

300wm 178@3000 Amax BC.495 600 65/25 1000 280/82

 

There is more scope to improve the 300-these are just SAAMI commercial loads.

 

So,for club and semi serious shooting out to say 750,the 260 will be better than the 308. If you get more serious,the 300 wm is a different class-though still not the "in cartridge" for 1000y,though it once was.

 

The 6.5s are more shootable-less recoil (that is not just a comfort thing-very few can shoot so well with a heavy recoiling rifle).

Target shooters will tend to favour the Creedmoor,but there isn't a lot in it for the club shooter,except less choice of factory rifles.

If you are seriously wanting to shoot 1000 yards none are among the best choices,currently.

 

gbal

[Rabbitter]

Always enjoy reading your posts, gbal.

 

I've seen you mention the 'hot 7mms' a few times. To be clear, which cartridges are we talking about in these terms?

 

kind regards

 

 

Ian

[gbal]

Thanks Ian, I now have the luxury of time to expand a bit. But sometimes miss too-the 7s have always been around (think 6.5 swede and 7x57 deer cartridges).

 

The currently favoured are the 7 Shehane (the once near obsolete underated 284 win ,wildcatted in an Ackley ish way),the Short magnum Winchester 7WSM,and less popular the Remington version,7Saum.

There are others ...these are big enough cases to comfortably shoot high 180 g ish high BC bullets around 2950-3000 fps-which is the current optimum compromise/balance between sheer power to beat the wind,and shootability to reduce wind variance effects,but allow reasonable shooting speed and comfort,even a string of shots in a short -20 ish secs-steady wind conditionas well as a wider shooting window in more windy conditions.

The 6BR is a much smaller cartridge,but can be loosed of fast enough to maybe get 5 shots in the same wind conditions (if the wind etc is fairly benign)..that is increasingly difficult with the big 30 cal magnum boomers; the 7s are ,well,somewhere in between ( except of course the big hot 7s-7 STW, 7WMag,7-300 Winmag...and so on ...7Dakota and on to the ragged edge of reason....7-338..The motivation for this class is long range delivery of increased energy for hunting bullets) Ouch,both ends.

 

Could a 7Rem mag work-well,yes.It's sometimes seems a bit arbitrary which cartridges get the development for LR target work...the 284Win (refered to as the straight 284, ie not modified a la Shehane) was virtually obsolete before it was picked up as a good one,and many shoot it in Fclass-brass from the box,etc. "enough is enough" :-)

 

gbal

[Finman]

Back to the OP (.260 vs 6.5x55), I think that the Swede has a lot more to offer: it can handle 140gn bullets easily (I have achieved 3000fps with 46gn N160 and a CCIBR2 primer with Lapua cases out of my 22' tube), it is inherently accurate and does it all with lower pressures than the .260. I don't understand the fascination with short actions, unless one is likely to require multiple shots in a short period of time and fancies a 'tacticool' rifle... As for the boltface, I had similar misgivings up until a number of gunsmiths in this site pointed out that one can use a .308 bolt face to build a 6.5x55 and vice versa...Paul Mauser had a few good days when designing both the 6.5x55 and the 7x57...most designers since are trying to reinvent his wheel...

 

all the best with your choice,

 

Finman

[adriandavidb]

Many thanks Guys; I think it sounds as though, should I constrain myself to the original options, the 6.5 x 55 has it! Same bolt face as the .308 family too, result!

[bradders]

Many thanks Guys; I think it sounds as though, should I constrain myself to the original options, the 6.5 x 55 has it! Same bolt face as the .308 family too, result!

Not to throw a spanner in the works, but there is a difference.

Looking on the web it would seem that a proper 6.5x55 has a head dia of .480" whereas .308 etc has a head dia of .473".

So if I have this right, Euro 6.5x55 brass may have trouble in a rifle of similar calibre built on an American action.

I did see this issue once while visiting another Gunplumber and it meant chucking the bolt in the lathe and opening the face up slightly, but it was a few years ago and I don't remember the finer details.

I'm sure someone else can enlighten this on this though

[Andrew]

Not to throw a spanner in the works, but there is a difference.

Looking on the web it would seem that a proper 6.5x55 has a head dia of .480" whereas .308 etc has a head dia of .473".

So if I have this right, Euro 6.5x55 brass may have trouble in a rifle of similar calibre built on an American action.

I did see this issue once while visiting another Gunplumber and it meant chucking the bolt in the lathe and opening the face up slightly, but it was a few years ago and I don't remember the finer details.

I'm sure someone else can enlighten this on this though

I've got a Winchester Model 70 6.5x55 and have no problems with European ammo.

I also have a 6.5x55 built on a Commercial FN action that was originally a 30-06. The European cases bit the bolt face just fine.~Andrew

[gbal]

I have a switch barrel Bat action in 7 Shehane(improved 284, a rebated .473); 6.5x55 Swedish AI (.479/.480) and 6BR (.473).The original bolt for 6.5x55 works just fine with the two smaller cartridges...maybe not vice versa (ie smaller won't take larger without some modification...or even with...?-hence a bit of confusion?)

The early Mauser Swedish rifles go back a long way (over 100 years-one reason some commercial loadings are 'conservative' (140@2650) in deference to old actions-there is no way to accurately assess pressures.

140 at 2950 (Ackley Improved) from a 25 " barrrel in a very strong modern action is enough for me for potential sub 1/2 moa at 1000y.

gbal

[bradders]

I've got a Winchester Model 70 6.5x55 and have no problems with European ammo.

I also have a 6.5x55 built on a Commercial FN action that was originally a 30-06. The European cases bit the bolt face just fine.~Andrew

Like I said, I have read about it and have seen it personally on one occasion but have also heard it at least one more time from a Gunplumber here, so there you have it

[dannywayoflife]

I've found that the T3 x55 has the same bolt face as a 308 family of cases. My mate had a x55 built on a old shot out 243 action. The x55 in a T3 is a awesome tool. I miss mine dearly.

[banus02]

good afternoon ,interesting thread .just to add I have just tried a 6.5x55 ppu case in my 308 shell/cases holder and it will not fit but 308 will fit in 6.5x55 shell/cases holder

[Rabbitter]

Surely due to the length of the case rather than the diameter though?

[gbal]

I think I can see that a .473 might fit into a .479,though it might not be an ideal fit;and that vice versa doesn't fit.......(it's mainly about diameter,though perhaps a little about 'thickness'-thicknesses may be very close.)...

[Laurie]

Bradders is correct in that the 6.5X55 case-head is nominally around 10 thou' wider than that of the cases based on the ye olde 7.9X57mm Mauser - today's 308 and offspring via the .30-06 and various other Mausers. Most bolts from rifles and actions intended for the latter will accept 6.5X55 cases, but it's suck it and see. All Savage bolt-heads for instance appear to have enough slack to take the 6.5X55 without modification and that applied when Osprey Rifles rebarreled a 6.5-284 to 6.5X55 for me, Stuart Anselm saying there'd been no problems whenever he'd tried it.

 

They don't use the same shellholders though whether press type or for the Lee AutoPrime devices. In the Lee classification, it's #2 for the standard Mauser / 308 / everything else bunch and #3 for the 6.5X55 which it shares with very few other designs, the rimmed .30-30WCF oddly enough. I can confirm that the '55 case doesn't fit the 308 etc holder having inadvertently attempted it on more than one occasion, but I'd have to try it again and look hard at it to see exactly where the mismatch occurs. (I haqve a vague feeling though that one make of dies, shellholders etc does see the 6.5X55 fit that company's 308 shellholder model.)

 

As pointed out by others, 6.5X55 doesn't see much tactical rifle use here or in the USA because its extra 0.315" OAL (3.15" COAL) over the 308 group necessitates a longer action and more often than not associated magazine, and the popular models tend to be built on short actions for 2.8-2.9" COALs. It does work in most single-shot target actions OK albeit may require a live cartridge to be unloaded through bolt removal from the receiver. Perhaps unsurprisingly, things are rather different in Scandinavia where it's used in a rapid fire competition called 'Stangskyting'.

 

See:

 

http://bulletin.accurateshooter.com/2012/04/scandinavian-bolt-rifle-speed-shooting-stangskyting/

 

for an impressive display using a modern Sauer 200 STR magazine competition rifle. STR = Scandinavian Target Rifle and is configured for magazine operation with the 6.5X55, although you could buy it in 308 Win too if memory serves.

 

Although the 6.5X55 is a superb cartridge, the potential extra performance over the smaller 6.5mm trio - 6.5X47 Lapua / 6.5mm Hornady Creedmoor / 260 Rem isn't that large and wouldn't give any great advantage in rapid-fire tactical type competitions as practised. In fact, it may be a disadvantage with extra recoil = more rifle disturbance / extra powder = hot barrel quicker (with a reduced life too). The US PRS tactical series is currently dominated by 6XC and the 6mm wildcat version of the Hornady Creedmoor with 6.5X47L, 6.5 Creedmoor, and 260 trailing somewhat behind in popularity. In single shot long-range precision disciplines, it sees some use in custom rifles, but if you want a long-range 6.5, most people will opt for the 6.5-284 first. Its niche in this type of competition is 'Factory Class' where this applies as there are some excellent off the shelf models such as the Tikka T3 Varmint. Alan Seagrave has shot several stunning 1,000 yard Bench Rest groups with his example.

[Andrew]

... In fact, it may be a disadvantage with extra recoil = more rifle disturbance / extra powder = hot barrel quicker (with a reduced life too)....

I think your grasping at straws on this one. In the case of the 260 the 6.5x55 only has a 3% larger case capacity, iirc. I doubt you'd be burning many barrels at a significantly higher rate than a 260. I think that when loaded similarly, to similar pressures, they would stand about equal.~Andrew

[gbal]

Relative Recoil Factor:

 

6.5x55 Swedish 1.72

 

260 Remington 1.73

 

243 Win 1.25 ,7-08 Rem 1.80 ,and 308 Win 1.95 just for comparison/some idea of this RCF scale.

 

(SAAMI specs-hot loading will change recoil and rifle weight and fit will change felt recoil).

[Laurie]

I think your grasping at straws on this one. In the case of the 260 the 6.5x55 only has a 3% larger case capacity, iirc. I doubt you'd be burning many barrels at a significantly higher rate than a 260. I think that when loaded similarly, to similar pressures, they would stand about equal.~Andrew

 

 

Maybe 3% as the two cases lie empty on the reloading bench. Actually ~10% as loaded due to the 6.5's long neck and very much longer usable COAL so bullets are seated less deeply in the case.

[Laurie]

I think your grasping at straws on this one. In the case of the 260 the 6.5x55 only has a 3% larger case capacity, iirc. I doubt you'd be burning many barrels at a significantly higher rate than a 260. I think that when loaded similarly, to similar pressures, they would stand about equal.~Andrew

 

Relative Recoil Factor:

 

6.5x55 Swedish 1.72

 

260 Remington 1.73

 

243 Win 1.25 ,7-08 Rem 1.80 ,and 308 Win 1.95 just for comparison/some idea of this RCF scale.

 

(SAAMI specs-hot loading will change recoil and rifle weight and fit will change felt recoil).

 

 

If loaded to CIP PMax (55,000 psi) for the 6.5 SKAN, there's not much in it between them. Using a 130gn bullet which is common in tactical comps and Viht N160, 260 Rem at 60,000 psi produces 8.9 ft/lb recoil energy and 6.7 fps free recoil velocity in a 13lb rifle compared to same recoil speed in 6.5X55 9.0 ft/lb actual recoil energy. (MVs used for the calculator assume 24-inch barrel levels in both.)

 

Most people loading the 6.5X55 though in a modern rifle using Lapua or Norma brass are going to run the cartridge at the same sort of pressure levels as the 260 though, that is at or getting on for 60,000 psi. There is no benefit at all in using 6.5X55 otherwise as it produces marginally lower MVs with most 55K psi loadings. Taking the N160 charge up to just under 60,000 psi increases charge weight by 1.4gn and MV by 80 fps. Run these levels through the recoil calculator and the 6.5X55 now runs at 9.8 ft/lbs and 7 fps.

 

To put that into context, the 308 Win which has fallen heavily out of grace in this sort of use on recoil and even more so external ballistics grounds produces 10.3 ft/lb and 7.1 fps respectively assuming a 155gn bullet at 2,800 fps MV from 44gn powder and again in a 13lb rifle. So, the trio stack up as:

 

260 ............... 8.9 ft/lb

6.5X55 .......... 9.8 ft/lb

308 Win ....... 10.3 ft/lb

 

Taken out of context, people might scoff at the difference a 'mere' 1 ft/lb recoil makes. However, in real life most people are aware of noticeably different recoil levels between a 260 Rem rifle with 130gn bullet and 308 Win with a standard pressure 155gn load and they're only 1.4 ft/lb apart.

 

This all depends on factors such as the performance the competitor loads the ammunition to of course. However, looking at the top level American scene where 308 was replaced by the 260 and .260AI then by 6.5X47 and other small 6.5s loaded with 123s or 130s, but is now dominated by sixes loaded at very hot levels shooting 105s, every external ballistics and rifle handling gain is being identified and siezed.

[gbal]

Laurie,not in disagreement-apples to apples (usually not so) there seems little difference.

Are your 6.5 swedish comments just for competitive reloaders?

 

There are very substantial reasons for hunters to use the cartridge as loaded commercially-it just plain works-and in Scandinavia,it is rightly in continued use by a great many hunters who have a 6.5x55 and see no need to change cartridge or ammo (or rifle vey often).

I'm not sure about the fast shooting competitions-they probably are mixed commercial/reload.A bit like CISM-I doubt that Norma sell so much of their excellent 6BR ammo over here as they do pro rata in Europe?

 

I'm pretty neutral,but do run an Ack Imp version,for some longer range plinking enjoyment. I'd have no problem with a factory stalker,but the 6.5x54 suffices .... it's even older than me,and very considerably lighter :-)

 

g

[Laurie]

Yes, I'm assuming the OP is asking for help in choosing between the pair for competition use being in the 'Tactical' forum. Also, if factory ammunition is used, it'd virtually have to be the 6.5X55 as I think you'd be hard put to find any such in 260 Rem loaded with FMJs or HP match bullets it being treated almost entirely as a 'hunting cartridge' by most ammunition manufacturers. (HPS-TR might undertake loading of a match version for a customer if asked and given a large enough order.)

 

Bullet types aside, the 260 is probably loaded close to SAAMI MAP pressure levels, but most 6.5X55 factory levels are anaemic because of the concern over the 19th century military rifles' strength, in particular the M1894 Norwegian Krag and its successors. Even the M1894/96 and M1938 Swedish Mausers which are regarded as strong rifles by contemporary standards should really have their loads limited to around 45,000 psi.

 

I put a 30-inch heavy Bartlein match barrel onto a Savage 12 F-Class rifle in 6.5X55 fitted and chambered with a standard dimensions reamer by Osprey Rifles a few years back and had a very successful play with it for a year using rather heavier loads and 139/140gn match bullets. (I still have the barrel and it'll go back onto the rifle at some future time as it has lots of life left in it, and it shot superbly with the 140gn Berger LRBT model.) Two factory loadings were used as ballistics benchmarks, Hornady 140gn PSP deer ammunition and Lapua 139gn Scenar match.

 

The Hornady ammo averaged 2,487 fps and had an extreme spread in three figures, also burned dirty, almost inevitably due to its being seriously underloaded. Playing with QuickLOAD suggests pressures were in the mid 30,000s psi bracket, certainly wouldn't exceed 40,000 psi - absolutely in line with most US practice because of the Krag strength issue.

 

I expected the Lapua stuff to be loaded a lot warmer maybe even in line with the CIP SKAN 55K limit and it certainly produced more velocity, now up to 2,596 fps in the 30-inch barrel. Assuming Lapua will have used Viht N160 or something close to it and running this through QuickLOAD turned up a PMax value of 40,000 psi. So again, perhaps unsurprisingly, people with great experience of loading the cartridge commercially have stuck to performance dictated by19th century rifles. Looking at Norma's ballistcs for its medium game loads suggests the higher modern limit is being used though, and Norma always has offered a large choice of loadings as you'd expect and loaded them as warmly as allowed. (Back in the '80s there was a Norma 139gn 'Roe loading' that was deliberately loaded 'soft' for the small species, but it was withdrawn after a couple of years as sales were very poor.)

 

By contrast I got the same bullet (139 Scenar) up to 2,999 fps using Lapua brass and N160 in the 30-inch barrel without blowing any primers or stretching case-heads on a single firing, not that I'd ever use such a load or recommend it to anyone as it had to be producing in excess of 60,000 psi, substantially so. The match load I developed and settled on used the 140gn Berger LRBT and Viht N165 for around 2,850 fps. I assumed it would be over-pressure for the 55,000 psi SKAN limit, but I noticed recently that Lapua's cuurent data quotes some 6.5 SKAN loads for use in modern rifles, and my N165 charge weight just fell right on the quoted maximum. QuickLOAD suggests pressures a bit below 55,000 psi in fact.

 

I'd agree that factory sporting ammunition works extremely well in its intended role despite the 'modest' loads and energies. Playing around with QuickLOAD and 43,000-45,000 psi type loadings, it still produces around 1,850 ft/lb ME with 140s in 20inch barrels, but I wonder if some of the anaemic US loadings like the Hornady I tried are actually deer legal in England and Wales with some of the really cut down rifles in use these days. Without a doubt, some 140gn factory loadings will fail the Scottish minimum velocity requirements even in standard barrel lengths never mind chopped down ones, which says more about the laws being 'fit for purpose' than the ammunition I'd suggest.

[gbal]

Laurie,I hold no brief for the cartridge especially,nor hot handloaing,especially. As Forker says " factory specifications have been set very much on the mild side' -in deference (aka damages claims)-to the many ex military surplus rifles esp in USA. The current US commercial 6.5 Swedish 140g loads,24 inch test barrel,are:

 

Norma Nosler Partition @2690 fps and 2250 ft lb

Sellier &Bellot SP 2671 2199

Fed Hi Shok SP 2650 2185

Rem Core Lokt SP 2550 2022

Win SP 2550 2020

Hornady Interlock SP 2525 1982

Lapua Naturalis 2625 2143

 

Norma 156 Oryx SP 2559 2269

Norma 156 Vulcan HP 2565 2271

Norma 156 Alaska SP 2559 2269

 

 

 

260Rem (24 inch)

 

Nosler 140 Partition 2800 2438

Federal 140 Sierra GK 2700 2365

Rem Core Lokt Ultra Bond 2750 2351

Rem SP 2750 2352

Rem Managed Recoil 2360 1731

 

The 6.5x55 Swedish is clearly down on the 260Rem as commercially loaded,but can be more or less equalised with home loading,in a modern rifle.

I don't have confirmed SKAN (1990) improved commercial loadings-maybe some above are such....(Norma?)...

 

g

[varminter]

Very interesting thread gents!!

Hope you dont mind me adding my experince in that i owned a semi custom Tikka T3 in 6.5-55 improved which could run the 140 grain bergers at 3000fps in load development but as i long range shoot and want to use the rifle for hunting to , i choose to use the 123 A-max running at a very comfortable 3000fps which turns out great for hunting and long range playing too!!!

Now for the 7mms - a while ago i fancied something that would drive the 162 A-max around the 3000fps and be accurate / good for hunting too!!

, but did not want the barrel life of the hot 7mms!!!

So it was decided to go for the 280 Ackley improved!!

Its running the 162 A-max @3025fps with great accuracy too!!!

Sorry for the plug - but its up for sale in the for sale section , due to me not been using it for quite a while now!!

Whatever you decide , i am sure you will have fun!!

All the best ,

Ray.