Too flute or not to flute?!?!?

[thetonk]

My 700 is going to the smith tomorrow to get rebarreled from a 308 mtu contour 20" with muzzle brake to a 6.5 creedmoor mtu contour 26". Don't think I'm going to bother with getting it threaded. But I'm trying to decide if I should get it fluted or not. N it's a beast of a barrel. Any thoughts

 

[JSTARSZ]

The MTU is a beast of a barrel (more like a truck axel) and some deep fluting will take some weight from it. I have rifles that some are fluted and some that are not but my M24 profiles are and it took some weight from them. I can't remember how much the difference but it was noticeable. If I were going to use a MTU profile I know I would do it!

Here is one from Kampfield - M24 Profile.

 

[JSTARSZ]

here is another one from Kampfield and was built by Mark Gordon at Short Action Customs

Also a M24 Profile barrel - 6.5mm Creedmoor

 

[CF_Smith]

Fluting is a tradeoff, the more perfectly round a barrel is (IE a well made heavy barrel), the more consistent it is due to harmonics. On the flip side the more constant heat the barrel is the more consistent it is due to harmonics. A fluted barrel will stay more consistent heat wise if you're shooting a lot of rounds without letting the barrel cool in between.

So you are trading off a perfectly round barrel for a barrel that cools down quick due to the increased surface area.

James

 

[rg1911]

For me, the weight savings and improved cooling are worth the fluting.

Richard

 

[physhphude]

Fluting is a tradeoff, the more perfectly round a barrel is (IE a well made heavy barrel), the more consistent it is due to harmonics. On the flip side the more constant heat the barrel is the more consistent it is due to harmonics. A fluted barrel will stay more consistent heat wise if you're shooting a lot of rounds without letting the barrel cool in between.

So you are trading off a perfectly round barrel for a barrel that cools down quick due to the increased surface area.
James

Good point.
Now I don't have any studies for proof, but in my mind, barrel fluting makes the barrel temperature change even more rapidly.

Fluting increases surface area to volume ratio. More surface area allows more diffusion of heat. Meaning the barrel cools down faster. Depending on the rate of fire, the change in temperature in the fluted barrel is greater than the non fluted barrel for the same period of time. Larger fluctuation means less accuracy.

It is not the elevation in temperature of the barrel per say that affects accuracy, it is the fluctuation. A hot barrel can shoot well. But a barrel that changes temperature rapidly might not.

So I would think that fluting in no way aids accuracy, and is mainly for aesthetics.

 

[downrange67]

Fluting is a tradeoff, the more perfectly round a barrel is (IE a well made heavy barrel), the more consistent it is due to harmonics. On the flip side the more constant heat the barrel is the more consistent it is due to harmonics. A fluted barrel will stay more consistent heat wise if you're shooting a lot of rounds without letting the barrel cool in between.
So you are trading off a perfectly round barrel for a barrel that cools down quick due to the increased surface area.

James

Read up on the Accuracy International testing on barrel fluting. There's a reason why they don't do it to any of the rifles that they put out.

 

[300sniper]

A fluted barrel will stay more consistent heat wise if you're shooting a lot of rounds without letting the barrel cool in between.

Sure about that? More consistent heat wise?

 

[Iron Hide776]

How fast do you have to shoot to heat up a barrel that much?

 

[CF_Smith]

Sure about that? More consistent heat wise?

Yes, because the heat will be dissipated more quickly. There's obviously extremes where you won't see a difference, but at a slower rate of fire you will. The difference may also be negligible, but it'll be there.

Read up on the Accuracy International testing on barrel fluting. There's a reason why they don't do it to any of the rifles that they put out.

Link to that? I'd like to read it.

All in all, the differences are indifferent, theres .5moa guns with and without flutting

 

[300sniper]

Yes, because the heat will be dissipated more quickly. There's obviously extremes where you won't see a difference, but at a slower rate of fire you will. The difference may also be negligible, but it'll be there.

When you flute a barrel, you remove mass. The barrel will heat up faster than it would have before it was fluted. It will also cool down faster. You said shooting a lot of rounds without letting it cool down. A fluted barrel will not be more consistent heat wise. The barrel before it was fluted would have a closer shot to shot temperature on the way up and on the way down.

 

[KingE]

http://www.snipershide.com/shooting/snipers.../183467-barrel-fluting-%3D-poi-shift.html

 

[CF_Smith]

When you flute a barrel, you remove mass. The barrel will heat up faster than it would have before it was fluted. It will also cool down faster. You said shooting a lot of rounds without letting it cool down. A fluted barrel will not be more consistent heat wise. The barrel before it was fluted would have a closer shot to shot temperature on the way up and on the way down.

Assuming that the barrel heats up faster then it can cool down, hence my extreme cases provision. Having shot a flutted barrelled gun, the barrel stays cool for very long if you're taking your time to shoot and using the principles of marksmanship, yes, if you plink as fast as you can the barrel will heat up faster then a heavy barrel, but it will also cool down faster. It's not intended to stay cool under rambo-fire.

I'm not saying that flutted is barrel is better, I'm just saying that it is a trade-off and there is gain from it. I run a Heavy barrel myself and love it.

 

[leadbullet]

Fluting a barrel is a waste of money, when it is burned up that extra cash is thrown away. If barrel contour is too heavy, go with a lighter one, David Tubb said that any profile heavier than medium Palma offer no advantages in accuracy, so that what all my barrels are.
Cheers.

 

[Supersubes]

Fluting a barrel is a waste of money, when it is burned up that extra cash is thrown away. If barrel contour is too heavy, go with a lighter one, David Tubb said that any profile heavier than medium Palma offer no advantages in accuracy, so that what all my barrels are.
Cheers.

This^^^


Get rid of your MTU contour barrel and use something reasonable, and fluting is not an acceptable solution IMO. I've owned many fluted barrels, I just don't bother anymore. I do use med palmas, but not because Tubb said to, it's because they have enough shank to do a setback, and don't give up any accuracy

 

[300sniper]

Assuming that the barrel heats up faster then it can cool down, hence my extreme cases provision. Having shot a flutted barrelled gun, the barrel stays cool for very long if you're taking your time to shoot and using the principles of marksmanship, yes, if you plink as fast as you can the barrel will heat up faster then a heavy barrel, but it will also cool down faster. It's not intended to stay cool under rambo-fire.

I'm not saying that flutted is barrel is better, I'm just saying that it is a trade-off and there is gain from it. I run a Heavy barrel myself and love it.

My mistake. I thought you said "A fluted barrel will stay more consistent heat wise if you're shooting a lot of rounds without letting the barrel cool in between."

 

[The Gump]

My 700 is going to the smith tomorrow to get rebarreled from a 308 mtu contour 20" with muzzle brake to a 6.5 creedmoor mtu contour 26". Don't think I'm going to bother with getting it threaded. But I'm trying to decide if I should get it fluted or not. N it's a beast of a barrel. Any thoughts

You will not gain anything in the accuracy department. You could hurt accuracy. A 26" MTU is FUCKING heavy to being with. Fluting won't take much weight out. Who cares if it stays cooler for longer? Frank did a barrel heat up, cool down, keep it hot all the time test and pretty much determined that it doesn't really matter if you're shooting anything but benchrest. I would even argu that constant cycles of heating the barrel up and letting it full cool and then heating it up again will cause more firecracking than running the piss out of the barrel and keeping it hot. But that's just my opinion/theory that I have never tested or seen tested.

I say dont flute it or go to a lighter profile barrel if you want to save weight.

 

[agbm]

Check out this video: SNIPER 101 Part 10 - Fluted Barrel Rigidity and Cooling Dynamics - Rex Reviews - YouTube

 

[CF_Smith]

My mistake. I thought you said "A fluted barrel will stay more consistent heat wise if you're shooting a lot of rounds without letting the barrel cool in between."

All good!

 

[mallrat]

Like the look? Flute it in the desired pattern.
Want less weight? Run a slimmer profile.
Want it to run cooler? Increase the clearance/airflow around the barrel.
JMHO, Spend your money as you see fit.

 

[RHunter]

So I would think that fluting in no way aids accuracy, and is mainly for aesthetics.

This is absolutely correct.

If barrel contour is too heavy, go with a lighter one, David Tubb said that any profile heavier than medium Palma offer no advantages in accuracy

A heavy barrel assists with recoil which is a real plus if you are shooting 100 rounds of 338 Lapua Mag in one day and the time it takes to re-acquire your target in semi autos.

Some barrels shoot better when hot, some better cold. It depends on the load dynamics. I.E. was the load developed for a cold bore shot or a hot one. I have one rifle that shoots a bit more than 1 MOA higher when hot than cold so I load my "cold bore" rounds 1-2 grains hotter than loads developed for the gun when it is hot to reduce this vertical spread in a long string.

Another factor you will encounter is how long the round sits in a hot chamber before being fired. If you use a temp sensitive powder like Reloader 22 and chamber a round in a hot chamber, you can see a difference of 100FPS in velocity pretty easy if the round sits in the chamber 1-3 minutes. Picture shooting in 30 degree weather and after 30 rounds your chamber is 130 degrees. Your powder in the first round was 30 degrees and your powder in the last round was 130... Big accuracy difference. These issues are not affected by the fluting of the barrel.