Those of us who have been around firearms for any length of time know that gun barrels heat-up from repeated firing.  The more rounds that go down the barrel, the hotter it gets.  The more frequent the interval between rounds, the hotter it gets.  This is very easy to see when completing a rapid fire string or several bursts with an selective fire weapon.

 

Unfortunately, some folks have to learn the hard way.

 

I was on a two week cruise with the Naval Reserve in 1967.  The USS HALSEY POWELL (DD-686) was a World War 2 'Fletcher'-class destroyer.  Our armory was well-stocked with WW2 weapons including .45 pistols, .30 Garand rifles, .30 carbines, M1 Thompson submachine guns, M1918A2 Browning Automatic Rifles, and M1919A4 .30 light machine guns.  About half way through our cruise, we had a familiarization shoot with the various weapons for members of the regular and reserve crew.

 

For some reason, we had a lot of people that wanted to shoot the BAR.  Every shooter got to fire a full magazine from the weapon.  By the time my student was ready to shoot, the BAR had fired approsimately 200 rounds on full automatic and its barrel was HOT.  My student came up to receive the BAR.  I told him that he should grab the BAR by the forearm while I held it by the heel of the stock and the upper part of the forearm.  All my instructions were in vain: his right hand grabbed the gun across the barrel!  The student let out a blood-curdling scream and jerked his hand back.  I yelled: "Corpsman!  Corpsman!!"  The hospital corpsman was with us almost immediately and my student's palm had a two-inch wide blister from the web of the hand to the backside.  The corpsman quickly took my student back to sick bay where is burn was treated and his hand bandaged.  The rest of the shooters who witnessed the scene gained a healthy respect for hot barrels.

 

In 1970, one of our Mobile Support Team detachments was getting ready to deploy to support SEAL/UDT operations in South Vietnam.  The normal procedure was to go to the Marine's Camp Pendleton, California, ranges to give the deploying crews weapons training.  Unfortunately the detachment was deploying within a week and the Marine ranges weren't available.  A phone call to North Island Naval Air Station on the opposite side of the town of Coronado from the Amphibious Base, solved the problem.  They said to come over and use their range.

 

On the morning of the shoot, we loaded weapons and ammunition aboard a 2-1/2 ton truck and drove to the North Island range.  The range was run by a crusty old Chief Aviation Ordnanceman.  The chief was very proud of his range; it had just been rebuilt by a bunch of brig rats (prisoners from the base lock-up).  We had 9mm and .38 pistols, M16 rifles, M60 machine guns, and two .50 M2HB Browning machine guns (with another two held back to replace the hot guns with cold ones). 

 

I asked the AOC whether the .50's were too powerful for his range. 

 

"Naw, Gunner.  If the .50's chew-up the backstop too much, I'll just get another batch of brig rats to rebuild it."

 

"OK, Chief.  If you say so, we'll shoot them."

 

The pistols were fired first and everyone picked up on the idea that they were defensive weapons at best.  The M16s, M60s, and the .50s were then arranged on-line.  The M16s were fired first in both semi-automatic and full automatic.  They were then returned to the racks.

 

Next came the machine guns.  We broke up the detachment members between the M60s and .50s.  We showed the students how to load the guns and where the controls of the individual guns were.  I gave the .50 gunners some extra instructions:

 

"The student will get a chance to run about 50 rounds through the .50 BMG.  I want you to use short bursts of 3 to 5 rounds.  We'll swap hot guns with cold guns about every 250 rounds.  When you are done firing your 50 rounds or you get at 'cease fire' from me, I want you to immediately open your top cover, drop the belt out, and cycle the cocking handle to remove the live round from the barrel.  I don't want to see any cookoff discharges caused by hot barrels."

 

The first batch of students got about 300 rounds through each of the two guns before we decided to swap them for cold guns.  I put asbestos gloves on both hands, gripped the gun by the barrel carrier and rear spade grip, and had a student trip the pintle latch lever on the M3 tripod.  I jerked the gun out of the tripond and carried it over to the wood rifle rack.  I sat the spade grips in the bottom cutouts of the rack and rested the barrel against the barrel cutouts in the top of the rack.  As soon as the hot barrel hit the wood, it was just like a wood burning set -- lots of white smoke and scortched wood smell.

 

"Anyone have a cigarette?" 

 

One of the students offered me a smoke. 

 

"Watch this!"  I lit the cigarette from the hot .50 barrel. 

 

That really made the student's eyes widen.  By the time we were done on the range that day, all our students had a healthy respect for hot barrels.

 

Later, overseas, we had one of our guys burn-up a .50 barrel.  In his case, it was returning fire that came from an ambush.  Harry's gun had 700 rounds; one 100-round box was on the tray attached to the gun cradle and six 100-round boxes were stacked against the engine firewall of the Light SEAL Support Craft's crew compartment. 

 

The LSSC got hit on extraction.  The SEALs were recovered without incident and Harry hosed-down the beach with the .50.  Harry was "Mr. Leadfinger" when it came to firing the .50.  He dumped the whole 100 rounds in one burst, cleared the empty can, and reloaded another one.  He did the same thing with that one and the other five remaining cans.  All .50 ammo was expended when the LSSC cleared the ambush site.

 

The next morning, Harry came up to me and asked me to check his gun, because "It got a little hot last night."  I grabbed my bore erosion gauge and we went down to the boat.  Harry used the cocking handle to pull the barrel extension back about a 1/2-inch and I unscrewed the barrel.  I took the gauge and dropped it into the chamber.  To my surprise, the gauge went about 1-inch below the end of the barrel.  The barrel was shot-out. 

 

We replaced the barrel with a new one and scrapped the old one.  As I was headed back from the armory, one of the guys that had been with Harry on the LSSC the night before asked me, "Did you replace the barrel?"

 

"We sure did.  It was shot-out.  The erosion gauge was off the scale."

 

"Well I figured it couldn't have been much use after last nigh.  Harry put so many rounds though it so fast that the whole barrel was glowing a bright orange-red.  Boy, was that sucker hot."

 

"No wonder that barrel was junked.  He could have saved me from gauging the barrel if he'd told me that."