I thought of this while reading the "How hot is too hot" thread. In Saving Private Ryan the Germans would need to replace the barrels on their heavy guns after long periods of sustained fire, assumably because they had worn out, or it was just part of their SOP to alternate them. On what guns did/does this apply to and is this still in practice anywhere? How many extra barrels did each team carry with them?

Back in the 80s we used to practice swapping the M60 barrels.

In the 3-man 60 team, the ammo bearer also carried the spare barrel bag.

Quoted: On what guns did/does this apply to and is this still in practice anywhere? How many extra barrels did each team carry with them?

Well, the MG42 type is still used in many parts of the world to this day, so yes. The MAG 58 has a great quick change barrel also. Probably carried into the US model (M240G or some such).
That's one thing the Browning series of MGs lacks, but they also have a much heavier barrel to begin with.

The M-60's barrel change was awkward and not the best system: weapon and one spare barrel. About the same as the M-240 for changeout for rounds fired.

The M-240/Mag 58 is an improvement but still takes two hands to do right: weapon and one spare barrel. Changeout at about 200 in sustained fire (in 2 min utes or less) I don't remember the other particulars though

The MG-3 has the best and about the fastest barrel change system I have ever seen on a MG. It is a world of difference from any U.S. weapon. It can be done one handed and by the gunner without him or his assistant gunner (A.G.) having to change position behind the weapon. Weapon and 2-3 spare barrels. It has a smaller and lighter barrel that cools faster than the heavier barrels of most MG's. Barrel change out at 150 sustained, 250 intermittant fire and 400 in emergency.

The Soviet PKM barrel is not that fast but I think it is superior to the M-60s' design.

The Soviet SG-43 is awkward and I would not want to have to change it under fire.

Quoted: In Saving Private Ryan the Germans would need to replace the barrels on their heavy guns after long periods of sustained fire, assumably because they had worn out

Now if I am correct it was to let them cool down, a hot barrel for a long time can cause you to not have much of a MG left.

Quoted: I thought of this while reading the "How hot is too hot" thread. In Saving Private Ryan the Germans would need to replace the barrels on their heavy guns after long periods of sustained fire, assumably because they had worn out, or it was just part of their SOP to alternate them. On what guns did/does this apply to and is this still in practice anywhere? How many extra barrels did each team carry with them?

The Danish Army still uses the MG-3 (or MG-42/59) which is the German MG-42 rebarreled for 7.62 NATO.  On some of them the cyclic rate was reduced from the original 1200 rpm to a more economical 900 rpm.  I believe a number of armies aroudn the world still uses it, mostly because the design still doesn't exist that is better for a light 7.62mm belt-fed machine gun.

It is used in 2-man teams, and the assistant carries the spare barrel in a narrow metal contained that is slung on the back.  The assistant also has an asbestos cloth/glove so he can handle the hot barrel.  The metal case is also constructed so that when it lays open on the ground, the hot barrel can be laid diagonally across it, thus cooling with very little contact with the container.

It takes about 3 to 5 seconds to switch the barrel during a firefight for a trained assistant - and it is done from where the assistant is anyway, so he/she doesn't have to move or reach to do so.  There were specific guidelines for how many rounds you should switch the barrel out after, but I've forgotten, and we mostly did it by feel (and when there was time).  

I have never heard of or seen an MG that has a barrel change as aesy as the MG-42.

Quoted: The M-60's barrel change was awkward and not the best system: weapon and one spare barrel. About the same as the M-240 for changeout for rounds fired. The M-240/Mag 58 is an improvement but still takes two hands to do right: weapon and one spare barrel. Changeout at about 200 in sustained fire (in 2 min utes or less) I don't remember the other particulars though The MG-3 has the best and about the fastest barrel change system I have ever seen on a MG. It is a world of difference from any U.S. weapon. It can be done one handed and by the gunner without him or his assistant gunner (A.G.) having to change position behind the weapon. Weapon and 2-3 spare barrels. It has a smaller and lighter barrel that cools faster than the heavier barrels of most MG's. Barrel change out at 150 sustained, 250 intermittant fire and 400 in emergency. The Soviet PKM barrel is not that fast but I think it is superior to the M-60s' design. The Soviet SG-43 is awkward and I would not want to have to change it under fire.

I like the M240 method better than the MG42 method, because you don't need an asbestos mitt.  

The one use for your weak hand is to hit the release button in order to rotate the carrying handle to unlock the barrel with the firing hand than lifting off.    

Very interesting stuff. I remember watching all the old war movies where they would show someone handling an M60 or some other, and they never addressed the barrel changing aspect. Of course those were just movies so..., anyway thanks for the info.

I never had a SAW, but I can remember changing out barrels on the M60. In a firefight you don't always have the time to stop firing long enough to swap out the barrel. There were some M60 barrels that turned white hot, so hot that you could see the rounds going through the barrel and the rifling was gone at that point, but it still fired.

From what I've read the Finns used a smg with quick change barrels & actually put them to good use in the Winter War stacking up Soviet troopers like firewood.

When we use the saw its a one man job, bolt back push release lever with left hand and pull barrel forward using the handle on it, then the new one just pops right in.  Takes all of 5 seconds

The M2 .50 cal has extra barrels to change out.Its been awhile but,as I remember there not to bad.Just  takes a few seconds.The hardest part to get used to is using those damn big mits to do it.

Nothing like a nighttime spend-x with the SAWs shooting 2 or 3 boxes in a couple minutes. You can see the flame as rounds are going down the barrell well before they leave the muzzle. It's enough to make ya stand there and shout " TAKE THAT YOU 5.56 BITCH!" Ok maybe it's just me.

  In our unit we rarely use the spare barrels for the SAW. The barrells for the 240 naturally go wherever the gun goes along with the tripod.

Quoted: The M2 .50 cal has extra barrels to change out.Its been awhile but,as I remember there not to bad.Just  takes a few seconds.The hardest part to get used to is using those damn big mits to do it.

an M2 comes with only one barrel. 'Course there is nothing stopping you from using other barrels, since matched barrels to receievers is not so important when you have to set headspace and timing manually each time you mount the barrel - hardly something you would want to deal with in a firefight. Takes more than a few seconds.

Adam
At least Marine M2s come with 2 barrels.  

Every Army .50 I have worked with has 2 bbls. it is part of the B.I.I. with the weapon. And changing them is time consuming because you need to set headspace.

In reference to the WWII Germans, the procedure was to change the bareel every time an aammo can was emptied.  That was every 250 rounds.  Manuals called for barrels to be roatated in threes.  A machine gun "group" would consist of three men.  One gunner, One assistant, and one ammo bearer although everyone in sht squad was responsible for the gun. If the gun crew goes down, the first three men to the gun take over.  This happend until the battle is over, or they are all dead.

In reality, as the war went on, this changed. Ammo was carried in cans less, more often it was Vietnam style with the links around the necks of every one. Barrels would be used as long as possible.
A good crew was to be able to change barrels on the MG-34 in 6 secons. It takes me 10.  The MG-42 was 5 seconds.

I was a Cavalry Scout in the Gulf (C 1/3 ACR) and once we came across some REMF resupply troops (Reserves, unknown unit) who had a duece and a half with a .50 mounted on top. One guy asks us if we can show him how it works because they never used one before. So, we climb up there and start showing him how it works, turns out he had never even heard of headspace and timing, just screwed the barrel on and went. We told him it was a good thing he had never fired it that way.

The HK11, HK21E, and HK23E MG's also have quick change barrels.  There's a handle on the right side so you don't need a special glove to remove the barrel.

Yeah, the HK-21 system is ok. but I am not a fan of trying to remember to put the links in upside down and loading it seems to be a bit tricky: maybe I have not been shown the proper technique though.

It takes me about 5 seconds for barrel changes when I am taking my time on the MG-3.

Quoted: an M2 comes with only one barrel. 'Course there is nothing stopping you from using other barrels, since matched barrels to receievers is not so important when you have to set headspace and timing manually each time you mount the barrel - hardly something you would want to deal with in a firefight. Takes more than a few seconds.

There was an upgrade & retro fit done to allow you to swap barrels fairly quickly without having to redo the timing.

216.239.51.100/search?q=cache:bBlm5JhLr0MC:www.gdarm.com/GDAS_Products/fact_sheets2/pdf-name/m2qcb.pdf+M2+quick+change+barrel&hl=en&ie=UTF-8

members.tripod.com/~Slippery_Jim/Machine-Guns/Browning_M2HB_Machine_Gun.htm