6.5 PRC Barrels - best options?

[samdk]

‘Most of its rigidity’ is the worrying phrase here.

No one seems to have any clear idea about quite how much rigidity is actually retained. And there seems to be considerable uncertainty about what happens to the dynamics of a barrel when the flutes are cut.

If you were to take two barrels of equal length, bore size, chambering and weight, one being fluted and one being unfluted, the fluted would be more rigid.

The engineering world is full of example of this very same principle, corrugated steel sheet, RSJ’s and lightening holes in sheet metal to name a few.

While I expect the gain in rigidity in two like for like barrels as mentioned above is only small it is a gain.

I imagine most people choose it for aesthetics. I have shot several rifles that group incredibly well at long range that are fluted so would not worry about accuracy loss based on my experience.

 

[Dave_45]

I don't have a dog in this fight.

But I will say that the majority of the UK gunsmith will offer fluting.
Brock and Norris , Alan Maughan etc

These guys make rifles that win titles regularly and won't deter you from fluting.

 

[Eric the Red]

Have you found any 95g loads ?
Factory ammo or reloading recipes ?
I’ve had a 6.5 PRC for a year or so and not found any (easily listed, Sierra, Hornady, Nosler data for a bullet that light).

I’ve loaded up 130 - 147g’s and they’ve all done well.
Bergara HMR wilderness 24” & Wildcat Predator 12…….my use before buying & now…..don’t carry it far !!!

Cheers Andy

95gr VMax - N550, RS60, RL17. In the 57.5gr - 58.6gr range (brass and barrel length dependent) - producing 3550-3600 in a 26in barrel. Same trajectory as a 26in 22.250 shooting 50gr VMax at 3850 - with half the wind.

 

[JH83]

24 inch barrel,if it was me ,I'd go 26 .

I've never seen the point In getting a magnum calibre and cutting the legs off it.

The blasers seem to hide longer barrels quite well, I think there PRC offering is 24.

You can probably get a semi custom for the same or less from a reliable smith.

Agree fully.

I also don’t agree with a previous post that there is no utility in a heavy barrel. There’s a reason varmint rifles exist, and target rifles have long heavy barrels. Wether the juice is worth the squeeze for you personally is the question.

A semi custom will likely be cheaper depending on components, but much more accurate. Resale will be less, if that is a consideration.

 

[Mungo]

If you were to take two barrels of equal length, bore size, chambering and weight, one being fluted and one being unfluted, the fluted would be more rigid.

At least that’s what some claim. But you can find an equal number who claim otherwise. And then various factions who claim that it depends on how you do the fluting and how/when you stress relieve the barrel.

As I said - there is no consensus on what actually happens when you flute a barrel. In the absence of proper measurements, everyone can put forward their pet theory based on half remembered high school physics.

 

[finnbear270]

Why muck about with loads / weights?, Charlie won't come back to you for a chat. (use the stalking load)

 

[Jvoelcker]

The weight reduction will be much more that the reduction in rigidity, use an RSJ as a comparison, that has had most of its metal removed and remains incredibly rigid.

The benefits of fluting are not that great but anything that aids your cause is a plus in my opinion.

I'm a mechanic, not an engineer and would argue that fluting will weaken the barrel.

Yes, designing with ribs from the outset, like your I beam analogy will add rigidity so a ribbed/fluted barrel wil be more rigid than an standard barrel of the same cross sectional area.

If you take two barrels and flute one the removal of the material will weaken it.

 

[Jvoelcker]

Why muck about with loads / weights?, Charlie won't come back to you for a chat. (use the stalking load)

Still pondering that one. I use 87gn vmax in my 243 for everything but then use 100gn for Reds.

I have been considering the 95gn vmax as the equivalent, small, fast and flat.

Something for a later debate.

 

[Jvoelcker]

At least that’s what some claim. But you can find an equal number who claim otherwise. And then various factions who claim that it depends on how you do the fluting and how/when you stress relieve the barrel.

As I said - there is no consensus on what actually happens when you flute a barrel. In the absence of proper measurements, everyone can put forward their pet theory based on half remembered high school physics.

If you have two identical barrels, so the same cross sectional area, removing material for the fluting will weaken the barrel.

If you have two barrels with exactly the same cross sectional area, one fluted and one round, the fluted one will be stronger.

 

[Mungo]

If you have two identical barrels, so the same cross sectional area, removing material for the fluting will weaken the barrel.

If you have two barrels with exactly the same cross sectional area, one fluted and one round, the fluted one will be stronger.

And since it seems that fluting is mainly done by cutting away from existing standard barrels…

 

[Jvoelcker]

And since it seems that fluting is mainly done by cutting away from existing standard barrels…

Yes.

If I was to do it, I would go with a heavier barrel to start with to end up with a fluted standard weight barrel, that's the theory anyway

 

[Lateral]

Perhaps in therms of heat dispersion, but it does offer a significant weight saving with minimal loss of rigidity.

If you had a long, heavy profile barrel, and then had it fluted, I'm sure the difference would be noticeable, but I had a Blaser R8 20", 19mm semi-weight barrel, and as part of a weight saving exercise, swapped to a standard 17mm profile, fluted 20" barrel of the same calibre, and that only saved a disappointing 355g/12.5oz.

That was on a 9.3x62, so comparatively light, compared to many of the more common calibres, where the fluting would need to be significantly deeper, to save very much in % terms.

Unless you're trying to save every gram, it does more for looks, than anything else.

I wanted a Blaser R8 6.5 PRC barrel, wanting to load a bullet weighing circa 140gn. I chose the ELD-X 143gn, which achieved 3070fps, with a load I was more than happy with.

 

[nun_hunter]

Yes.

If I was to do it, I would go with a heavier barrel to start with to end up with a fluted standard weight barrel, that's the theory anyway

I think this is what others aren't getting

 

[Lateral]

Meant to say, Quickload predicts circa 3500fps with the 95gn Vmax.

 

[Jvoelcker]

Meant to say, Quickload predicts circa 3500fps with the 95gn Vmax.

Do you have a Blaser 6.5PRC?

 

[Lateral]

Do you have a Blaser 6.5PRC?

I didn't make it very clear, did I

Yes, 580mm std profile barrel, which appears to work ok, on paper, with the 95gn,and works well with a 143gn. Haven't tried anything heavier, that I would only do, if I wanted to shoot way out there, but I have better calibres for that.

In the US, they shoot up to circa 156gn, but I'd be surprised if the R8 barrel twist would stabilize them.

 

[Bowland blades]

100 grain are the lighter 6.5mm bullets you can actually buy in the uk on a regular basis . i shoot 100 grain seirra varminters for smaller things like fox , crow etc . 100 grain barnes TTSX for all uk deer and 120 TTSX ocasionally , in lead its mainly 120 grain . My twist is 1-7.5 and its stabilizes all the above and will do ELDX and other longer bullets . 6.5 PRC isnt my choice , i went 260 rem because i have a whole load of brass from 243 - 308 as well as the ready formed 260 to go at . Simply neck up or size down , can get up to 3300 with 100grain and the powder is easily burnt on a 20" barrel .
if you go fast twist with the 95 v max too great a velocity with a fast twist you might just run into a few bullet break -ups at 3500 fps and its totally not needed besides the lower barrel life
remember twist rate is about bullet length not weight and copper is long for weight faster twist for longer bullets , shorter bullets will still stabilize but the fater the velocity the more you can slip into "dusting" in flight

 

[Jvoelcker]

I didn't make it very clear, did I

Yes, 580mm std profile barrel, which appears to work ok, on paper, with the 95gn,and works well with a 143gn. Haven't tried anything heavier, that I would only do, if I wanted to shoot way out there, but I have better calibres for that.

In the US, they shoot up to circa 156gn, but I'd be surprised if the R8 barrel twist would stabilize them.

Yes, it was a little confusing

Presumably stability would improve further with the 25.5" barrel?

 

[Lateral]

Yes, it was a little confusing

Presumably stability would improve further with the 25.5" barrel?

I think stability relates more to the twist rate, than barrel length ? With regard to the 95gn, and velocity, it will work better in the longer barrel.

 

[nun_hunter]

I think stability relates more to the twist rate, than barrel length ? With regard to the 95gn, and velocity, it will work better in the longer barrel.

Stability is down to the rpm which is linked to twist rate and velocity. A longer barrel should allow you to eek out a bit more velocity which in turn will give you greater rpm. A faster twist rate does this more dramatically.

A 300 Blackout and a 300 Norma Magnum will both stabilise the same 200 grain bullet but at very different velocities and so use a different twist rate to achieve that.