[37489]

Folks,

Which weight barrell: std, medium or heavy would be better at dissipating heat under sustained rapid fire? I am invisioning an E2 builid with 50 round drums and bipod for in-place perimeter defense.

Would it make any difference for semiauto use? How about full-auto?

How did the BAR manage it?

Looking forward to your comments.

 

[30Caliber]

At the last place I worked, we had little self adhesive thermometer thingies for recording peak temps. I don't recall the exact temps (I'm pretty sure I posted the results here--maybe 3-5 years back), but on my supermatch (heavy profile) the temp on the skinny part forward of the barrel was MUCH higher (40'ish+ degrees F maybe) than the fat part.

Fat barrels deal better w/ heat.

 

[30Caliber]

See here
http://m14tfl.com/upload/showthread.php?t=37066&highlight=temperature

 

[davidgcalderone]

Full auto will heat a barrel quickly. The operator really has to determine how quickly he wants to fire, the faster the rate of fire, the sooner the barrel wears out.

Now, if it is a life or death situation, barrel life goes out the window.

 

[dozier]

Yes, the heavier barrel is a bigger heat sink, and will handle the temp better. It still pays to be reasonable when using sustained fire to prolong barrel life. The use of a ventilated handguard will also help in cooling. dozier

 

[jens5]

Ventilated vs solid HG

Yes, the heavier barrel is a bigger heat sink, and will handle the temp better. It still pays to be reasonable when using sustained fire to prolong barrel life. The use of a ventilated handguard will also help in cooling. dozier

With that in mind dozier,will a ventilated HG produce more heat mirage than a standard HG?

 

[Bamban]

With that in mind dozier,will a ventilated HG produce more heat mirage than a standard HG?

Of course it does, you have vents for the heat to go straight up to your sight's view, whether irons or scope. The bench rest boys put mirage shield right over their barrels to minimize the barrel heat generated mirage.

 

[37489]

Thanks for the feedback folks

Thanks for the feedback folks. I was wondering if "thin to win like a radiator fin" was the way to go or "fat rat fink makes a better heat sink." I guess more is more in this case.

Anyone ever see any DOD advice / recommendation on full auto technique with the M-14?

 

[37489]

Interesting temp data

See here
http://m14tfl.com/upload/showthread.php?t=37066&highlight=temperature

I wonder what temps we are talking about for a glowing M-60 or MG-42. How did crews know when to make a barrell change? Round count?

 

[dozier]

Thanks for the feedback folks. I was wondering if "thin to win like a radiator fin" was the way to go or "fat rat fink makes a better heat sink." I guess more is more in this case.

Anyone ever see any DOD advice / recommendation on full auto technique with the M-14?

I'm guessing here, but I would think that 10 rounds of sustained fire as fast as you can pull the trigger in semi, would create as much heat as 10 rounds of full auto. The DoD has a recommendation in FM 23-8 on sustained fire. Info is duplicated in Kuenhausens 30 cal service Manual. dozier

 

[2336USMC]

Thanks for the feedback folks. I was wondering if "thin to win like a radiator fin" was the way to go or "fat rat fink makes a better heat sink." I guess more is more in this case.

Anyone ever see any DOD advice / recommendation on full auto technique with the M-14?

Check FM23-8, it will have rates of fire for sustained and max. Those rates need to be respected, not because of barrel life but a much more immediate reason: The M14 is not designed as a dedicated machine gun and fires from the closed bolt position. After enough rounds are fired fast enough the chamber can get hot enough to start cooking off rounds as they are chambered, which is bad. Then when rounds start cooking off and you try to clear the rifle, and a round cooks off just as it's coming out of the chamber as you pull the oprod back, that's really bad... GI8

This is why real machine guns fire from the open bolt position. Between bursts the chamber is clear and a round isn't sitting in there getting toasted. DI5

 

[2336USMC]

I wonder what temps we are talking about for a glowing M-60 or MG-42. How did crews know when to make a barrell change? Round count?

Yes, round count and rate of fire. Gunners are trained to change barrels after a certain number of bursts at certain rates, depending on the gun (and the severity of the situation... GI7)

Unless you have one of these:

[ame]http://www.youtube.com/watch?v=-iS6T8DW-h8[/ame]

 

[dozier]

With that in mind dozier,will a ventilated HG produce more heat mirage than a standard HG?

Yes it will to a degree. Will relate a story. In Basic Training we were given four full mags of ammo and instructed to engage 4-600yd targets as fast as you could pull the trigger/reload. My M-14 had a ventilated handguard. Unfortunately my barrel was slathered in oil(over-oiled). Not only was there heat mirage, but burning LSA(smoke) coming out of the vents. Even thru the smoke, I never had a problem using the iron sights engaging the man size targets. Unless you are shooting precision paper targets, I think the mirage thing is somewhat overblown. I now use Eezox on my barrels for rust prevention. It dries to the touch. Now I haven't repeated this test on my springers lately, as ammo isn't as cheap(free) as it was in those days. I'd be interested to hear other comments about rapid fire shooting/mirage from somebody who has duplicated this. dozier

 

[37489]

Sweet!

Yes, round count and rate of fire. Gunners are trained to change barrels after a certain number of bursts at certain rates, depending on the gun (and the severity of the situation... GI7)

Unless you have one of these:

http://www.youtube.com/watch?v=-iS6T8DW-h8

Kinda takes care of the pesky extra barrel tagging along don't it? Unless its WWI and you are going to need more than 15,000 rounds.

 

[brassmagnet]

I wonder what temps we are talking about for a glowing M-60 or MG-42. How did crews know when to make a barrell change? Round count?

IIRC the barrel change on MG-42's was required after 200 rounds, as they are thin barrels. Easily changed tho. The 1919 Browning didn't have a quick change barrel, but it was about 1.25" D so could withstand a lot. Cook-offs were not uncommon with the air cooled Brownings after sustained fire. I have a clip of a short barreled 1919A4 with the glowing red barrel from the heat after they put a 1000 round belt through it. I'm sure the barrel was un-rifled after they got finished! GI2

 

[pepsi71ocean]

correct me if i am wrong, but wouldn't it be easier to fit some kind of water jacket around the barrel, made from fiberglass, or something, and attach it to a condenser with a suction hose on it.

in theory it would create a coolant system similar to that of a car.

if the Op is going to use if as a S-A MG he might as well go after the look of it, lol

 

[jws1006]

Unless you have one of these:

[ame]http://www.youtube.com/watch?v=-iS6T8DW-h8[/ame][/QUOTE]

I GOTTA GET ME ONE OF THEMFOR MY BIRTHDAYP_G