6.5x47l vs 6br barrel life

[ofrn]

Thinking about switching to 6BR after I burn out this 6.5x47l barrel due to being cheaper to run.  The 6.5x47L was designed to have better barrel life than the 6BR, if you check out the overbore index over on accurate shooter the 6.5x47l is actually more overbore (case volume vs bore area) than the 6BR.  This to me would indicate that the 6BR should have better barrel life all other things being equal (loaded to equal pressure same shot rate etc)  I have seen it mentioned from Laurie himself on accurate shooter who's words I follow very closely that the 6br normally goes off around 1500 rounds vs the 6.5x47l at 2500 rounds. Hopefully Laurie sees this post and chimes in.  What would I be missing here? why would the 6BR be getting less barrel life when it is LESS overbore than the 6.5x47l all other things being equal.

[maximus otter]

Overbore chart.

maximus otter

[terryh]

OFRN,

Depending on how you are pushing the 47 I’d be a bit disappointed if it stopped at 2500 rounds?

Just personal experience but that seems a low figure - caveat I’m not running my 47 like a small 6.5-284!

that chart linked by MO is ‘interesting’ but does not take into account a lot of other variables so the hard numbers for 6BR & 6.5x47 are so close as to be the same in practical terms IMHO

Brgds

Terry

[Laurie]

If you look at Lapua's factory loads for the 6.5X47L, they are mild, so I presume the aim was to run the cartridge at lower pressure levels than the 6BR for 300 metre competition. A bit of modelling on QuickLOAD suggests they are loaded to around 56,000 psi.

Barrel life depends on so many factors when dealing with custom rifles and handloaded ammunition - pressures, propellant flame temperatures, rate of fire / barrel heat, and barrel material - that prediction is almost impossible. Is it for instance better to run a larger case cartridge at lower pressures than a small very high intensity one? If so 6.5X55mm would give a longer barrel life than 6.5X47L / 6.5CM / 260 Rem. (In Swedish Mauser loadings and with chrome moly barrels it does so by an enormous margin over most users' handloads of the smaller numbers in stainless match barrels.)

The other factor few people take into account is barrel material. Chrome moly steel erodes much more slowly than stainless and within stainless, people are finding that some makes and/or batches of custom match barrels have apparently been 'soft'. Some factory rifle owners of the 6.5s with their very hard hammer-forged barrels may get a shock when after eventually wearing them out find they get half the life or less with its custom replacement.

[Re-Pete]

To illustrate Laurie's point about barrel steels, I have a 6BR with a 30" Lothar stainless barrel that's done over 2000 rounds in my hands. The barrel was originally longer and installed on a Quadlock around 2007.

It went round the galaxy before it was shortened a bit at both ends (to get back to some solid meat?) and fitted to a Musgrave action. I bought it in 2013.

My load (RS52) produces an MV of 2900 using Scenar 105's, and can hold <1 MOA at 600yds on a calm day.

There's a bit of fire cracking extending forward of the throat about 5-6cms, but thereafter, the original button chatter marks can still be seen.

 Lothar barrels are very hard.......so much so that some gunsmiths allegedly won't work on them.

Pete

 

 

[meles meles]

We believe LW use a PH grade stainless steel from Boehler for their premium barrels and this reported performance would accord with that. It's about as wear and erosion resistant as you can get without resorting to exotic (expensive) alloys

[ofrn]

great discussion fellas I has no idea the chrome moly barrels were harder than stainless. Unfortunately where I live in the coastal tropics of Australia things rust almost instantly with extremely high humidity and heat.  The reason I ask about barrel life is I often see things quoted in the US such as barrels are like tyres and cheap to replace etc.....here in Australia we pay 2-3 times what they pay for anything gun related a customer rebarrel from a quality smith will be well over $1000 au which for me is a significant investment so barrels are certainly not like tyres for me.

[Catch-22]

If a big concern for you is cost, then all the reloading equipment required to switch calibres isn't actually that cheap either.

Obviously you need new brass, bullets (I buy in bulk to make it cheaper), possibly different powder (also bulk), but then new dies, bushings (if neck sizing), cleaning brushes/jags etc. Doesn't sound much but everything added together is likely to be around 1/4 to 1/3 the cost of a new barrel. If you're already geared up to shoot 6.5x47 (excellent calibre btw), my own personal opinion would be to just stick with it.

[Big Al]

2 hours ago, Catch-22 said:

If a big concern for you is cost, then all the reloading equipment required to switch calibres isn't actually that cheap either.

Obviously you need new brass, bullets (I buy in bulk to make it cheaper), possibly different powder (also bulk), but then new dies, bushings (if neck sizing), cleaning brushes/jags etc. Doesn't sound much but everything added together is likely to be around 1/4 to 1/3 the cost of a new barrel. If you're already geared up to shoot 6.5x47 (excellent calibre btw), my own personal opinion would be to just stick with it.

Add to the above new load development for a cartridge you dont know. This will possibly take you longer to get the right load than it would to fine tune what you already know about 6.5x47 and again it just adds to the costs. Consumables used in load development quickly add up and at the end of they day all these shots are just a means to an end, bullets primers and powder aren't cheap.

Having said that, if you dont shoot much past 600yds I would prefer a 6BR as they are generally a more pleasant caliber to shoot with noticeably less recoil. Im afraid Im in the American camp though, within reason barrels are consumables.

[Re-Pete]

"within reason barrels are consumables."....................this must be the reason I'm now using Bergara blanks at £220 a pop, posted............that and the fact that they shoot better than I can.

Krieger set up the plant and trained the operators, allegedly.

Re-Pete

[Catch-22]

57 minutes ago, Re-Pete said:

"within reason barrels are consumables."....................this must be the reason I'm now using Bergara blanks at £220 a pop, posted............that and the fact that they shoot better than I can.

Krieger set up the plant and trained the operators, allegedly.

Re-Pete

It was Ed Shilen.

Yeah I previously had a Bergara barrel in 6.5x47. Nice button barrels, and you're right - good value for money.

A good stainless steel cut barrel blank is about £100 more. 

[Chris-NZ]

The 'change the gear for lower running cost" argument reminds me of folks who trade their bigger engine car for a smaller-engine car when petrol prices go up. The extra capital spend/ realising the depreciation on the old car would probably have paid for a decade of fuel difference.

[Re-Pete]

Ed Shilen?........that helps explain why they're so good..............

Can't see how the car engine analogy applies to a gun barrel, though. The Bergara barrel on our 6.5 shoots every bit as well as the Bartlein on our 308.

Re-Pete

[Catch-22]