Fluted Bartlein vs Proof Research sendero contours
Help Support Long Range Hunting Forum
Oh, it looks like a shooter alright. Yum.
That Curtis on that other thread looks badass as well.
You calling me stupid!!??
Did I call you that? I thought I typed "You'd have to understand science, no?" Lot's of folk don't understand science. I wouldn't claim those folk are stupid for that reason. I typed that because the science of the thermal conductivity was presented. You must not have understood it, or you consider blah blah blah to be more credible.
I did communicate that blah blah blah was "negative", and that blah blah blah isn't science.
And now I'm typing - blah blah blah doesn't negate the science.
Last edited:
RockyMtnMT
Official LRH Sponsor
lancetkenyon
Well-Known Member
Is that Manners in "Tac Swamp"?
Got a few more photos?
What color Cerakote?
My next build that I have all the parts on order for has a Manners PRS2 coming in "Tac Swamp", so I am researching Cerakote colors.
You're stepping into the realm of the underdogs? (That's intended with a smile). Which is not the equivalent of passive aggressive, to the passive aggressive sensitive. My thoughts on your post concerning the heat felt/sensed in the middle of the CF barrel and any associated conclusion:
The location in the bore where the maximum flux of heat (BTUs) is applied for the longest duration of time is the location where temperatures of the barrel will rise the most, all else being equal. The location where the majority of the heat and highest temperature is applied is immediately forward of the chamber, precisely where fire-checking and fire-cracking of the bore is first seen through a bore scope. This is the location of maximum impingement of heat along the length of the bore.
If I understood you correctly, that's more or less where you felt a temperature rise on the carbon fiber wrap after firing three shots. That's the same place my steel barrels experience the greatest increase in temperature. That doesn't mean the steel at that location of my barrels has a different thermal conductivity than other locations along the length of the barrel. It's all the same steel and has the same thermal conductivity at all locations - the exact same thermal heat transfer efficiency. Attributing the increased temperature to some difference in thermal conductivity of the barrel at that location is clearly improper with the 100% steel barrel.
Using the increased temperature at the location of maximum applied bore heat as an indicator of the thermal efficiency of a CF wrapped barrel is likewise, errant. It's even more complicated with the CF wrap thrown into the mix overlaying the inner steel.
Touching the steel bore and sensing the temperature has clear limitations. Firstly, there has to be a second 100% steel barrel under equivalent fire, to compare the temperature to. Also, a mere three shots places us right in the realm of maximum unsteady state heat transfer, which will mask/obscure the possibility of clearly sensible evidence one way or the other. Sustained fire conditions would be the more ideal touch test, but who wants to overheat their bore? Which is why I suggested the deep freeze test. I already know the results of the deep freeze test. The steel barrel will feel much colder for much longer. This isn't a completely fair test, because the property of the steel allows it draw and store much more heat from the hand than the CF material. The science explanation is that steel has a much higher thermal capacity than CF. So the steel will draw the heat from the hand much more notably. The sense of cold in the first few seconds would be most telling after grabbing the barrel pulled from the deep freeze.
I've never stated the inferior heat transfer ability of the CF wrap is any cause to avoid a CF barrel. You stated you're in the market for a CF wrapped barrel, so I'm offering my best effort to clarify all my prior Posts in this Thread. No one should read anything further into my posts than what I've typed: that my sole focus in this thread was the common and continuing false claim from CF barrel manufacturers that CF barrels conduct heat and cool more efficiently than a 100% steel barrel. I never stated anything beyond that.
I don't expect the CF wrap will significantly limit the effective bore life of CF barrels for LRHs who can easily avoid high rates of sustained fire. I avoid high rates of sustained fire with my all steel barrels. I'd do the same if I owned CF. More power to CF wrapped barrel owners. Indeed, I myself identified some obvious benefits of CF barrels. I would never buy one because I thought they offered longer bore life due to improved cooling efficiency. I expect their reduced heat transfer efficiency to constitute a minor drawback for the typical hunter, under reasonable rates of fire. That based on my understanding and expectation of barrels used for hunting, which is different than demonstrated, or proven, by science.
There are multiple good reasons to own a CF barrel. Improved cooling efficiency resulting in longer bore life - no, not a reason.
Last edited:
RockyMtnMT
Official LRH Sponsor
My only thought is that if the cf were keeping the heat from transferring in the same way that an all steel barrel does, that held in heat would seek a way out. That would cause it to transfer to the insulated portions of the barrel. In this case the breach portion of the barrel that is relatively close to the heat that is present would show more heat. It stayed at very near ambient temp. I was shooting my 338 Lap imp at the same time and it felt very much the same.
We will shoot these rifles together again and I will get more comparison.
Steve
We will shoot these rifles together again and I will get more comparison.
Steve
My breech and muzzle end remain cool after three shots also. 100% steel barrels.
The rate of heat transfer is also partially determined by the length / distance the heat travels. So expecting to sense heat anytime soon at each end of a barrel when the heat is applied in the middle is stretching it. I'm sure you've sensed this if you've soldered pipe or welded on pipe or simply heated up some pipe with a torch. Keep your hands away from the torched section of the pipe. Takes a while for the heat to conduct out down the length of the piping.
The rate of heat transfer is also partially determined by the length / distance the heat travels. So expecting to sense heat anytime soon at each end of a barrel when the heat is applied in the middle is stretching it. I'm sure you've sensed this if you've soldered pipe or welded on pipe or simply heated up some pipe with a torch. Keep your hands away from the torched section of the pipe. Takes a while for the heat to conduct out down the length of the piping.
Crowe284
Well-Known Member
The stock is elite midnight and the cerekote is tactical grey (H-227). I attached another photo taken with a little different lighting.
Attachments
lancetkenyon
Well-Known Member
Beautiful. Thanks. That will be my next color Manners.
RockyMtnMT
Official LRH Sponsor
I agree. But if you insulate the hot section of the pipe it will force the heat to radiate farther along the length of the metal to dissipate. Correct?
Steve
Correct. More heat would travel further along the axis of the barrel, toward each end, if the barrel is wrapped with insulating media compared to a non-insulated barrel. The magnitude of the heat conductance (flux) in the differing directions through the differing materials is where it gets complicated. I can't tell you how long it will take for the heat to conduct to the ends of your CF wrapped barrel, sufficiently for you to feel it with your hand. But it will take some time whether the barrel is insulated or not. There are too many variable factors, some being the number of shots fired and the rate at which they're fired, the mass / contour of the steel core of the CF wrapped barrel, the number of grains of powder burnt and the total BTUs of heat released internal to the bore by each cartridge, etc... Makes it impossible, in my opinion, to draw any conclusion from the temperature feel test. Bring an identical contoured 100% steel barrel to the testing grounds, fire both rifles at the same rate with the same load with a sufficient number of rounds fired, and then you can maybe draw some conclusion on the CF barrel compared to the steel barrel. Such a test minimizes the affecting factors, since both barrels are put through similar conditions over a similar length of time.
I tossed out the hot/cold feel test to get members to think about the consequences of conductive heat flow in a practical common sense way that we can sense by touch.
However there's nothing more definite and definitive on the conductive rate of heat transfer than the thermal conductivity coefficients of the CF wrap and barrel steel. We now have those values for both materials. It's a done deal. End of story. I wouldn't spend a lot of time trying to contest the science with a touch test. More futile than swimming against the tide in Cook Inlet, with 25+foot tides.
The other heat transfer property that was bandied about by the CF barrel manufacturer is used to predict/calculate instantaneous, very short term heat transfer rates. From my research, it has benefits of application in circumstances of very temporary/transient/changing temperature boundaries and swings in temperature. That's termed non-steady state temperature conditions/boundaries in the world of science. I'm curious what time duration qualifies under that engineer's definition of instantaneous. Because before the CF wrap can conduct any heat at all, the heat must first be transferred across the steel barrel core. After the combusting gasses release their heat to the lining of the bore, the steel bore must next conduct that heat radially to the carbon wrap across the radial thickness of the steel core. At the same time, some of that heat is being absorbed by the steel due to the heat capacity of steel (the quantity of heat energy stored in the steel for each degree rise in temperature). Does this border on instantaneous heat transfer? Applying that "instantaneous" coefficient to represent the rate of heat transfer in the carbon on a carbon wrapped rifle barrel is a complete misapplication of that coefficient. There's nothing we can do about short term heating and heat flux into the walls of the bore, other than not firing the gun. Heat is released and damage occurs with each round fired. We can reduce the damage to the steel bore per round fired, and increase bore life, by not firing successive rounds while the surface of the bore is already pre-heated from the prior round fired. Firing at rapid rates ensures the bore surface temperatures will increase higher than with the prior round, because the bore surface temperature is elevated with each round fired. So we can't avoid the instantaneous flash heat transfer to the bore surface. We can exert control over the bore surface temperature before touching off the next round and exposing the bore to another heat cycle. We have some ability to control how hot the bore/barrel become during repetitive fire. And this is a close approximation to maintaining an upper temperature inside the bore, and maintaining steady state-like heat transfer conditions. Holding the barrel temperature to "reasonable", not too high temperatures. The proper coefficient for steady state heat transfer is termed "thermal conductivity coefficient". Which is clearly very different than the fairy tale coefficient. Is there anyone with a CF barrel that really senses conductive heat transfer through their CF wrap at a rate 1000 times greater than heat conduction thru one of their steel barrels? Heat transferred from the bore to the surface at such an amazingly increased rate compared to steel. I'd think you'd blister your skin after 5 -10 consecutive shots. Would require a heat shield to prevent 3rd degree burns. That's what the fairy tale coefficient predicts, and that's how some common sense can identify its misapplication in promoting fabulous heat transfer rates thru CF wrap.
If the entire barrel, including the bore, were constructed of 100% CF, then the fairy tale coefficient application might begin to have some application. But CF barrels aren't 100% CF. They still have the plain-Jane steel core.
Last edited:
D
Deleted member 103481
Guest
After quite a few months I found a deal that made up my mind.... can't wait to heat it up!
