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Very stupid question on MG barrels

pointblank0

pointblank0

BOCN Supporter
Hello all,

Apologies for the prpbably very obvious question. When a MG is changed after the recomended amount of rounds fired, and a new one put in place (meaning the guns that can have the barrels changed in the field, and not by an armourer), can the old ones be re-used? It is something I have wandered about for many years but have never found out and keep forgetting to ask.

Many thanks,


Rob
 
The ones you can exchange are usually exchanged when they heat up too much. They can be put back into the gun after they have cooled down. Of course they are getting removed for good once they reach their limit in terms of wear and tear.
 
No stupit quistions, only stupit answers. :tinysmile_kiss_t:

You need a few spare barrels.

Rgds :tinysmile_twink_t2:
 

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Rob

The quick change barrels are usually just swapped out to cool down. And like EOD noted, their "life span" is figured in rounds fired. A concocted figure based on range testing. Respecting the firing discipline, they'll last upwards of 50k rounds. Goin' Rambo reduces that to a few thousand. Lots of variables depending on the barrel linings and ammo and many other factors. I used to have a couple of shot out MG42 barrels. Missing rifling, and even warped. Both indicators that marked them as scrap metal. Luckily, they are (were) relatively inexpensive as they made gazillions of them. Not sure what the going price is now. Used to be in the $30 range. Here are some of the spare barrel carriers in the lower right of the pic.

Rick

minigun 007.jpg

P.S. Welding gloves are real handy when swapping barrels. Actually, mandatory.
 
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So would a worn-out barrel still be illegal to own in the UK? I could really do with finding one for a MG15 as I am having difficulty getting a relic one deactivated without a barrel - seems the new regs were written by someone who had watched too many Sweeny episodes and a partial barrel is causing no end of problems!
 
I think thay still have to be plugged whatever % of the length of the barrel. I would imagine that a worn out barrel would still be more than capable of discharging some rounds. I'm not sure though. There was a post on here earlier on in the year with the scans of the proof house documants to be followed when deactivating, can't remember where they are though.
 
A "worn out" barrel is still capable of functioning as designed; just lacking in accuracy.

Rick
 
Interesting thread.
As has already been cleared up here once worn out they are scrap. They cannot be relined or bored as this costs more than to just make new.
As an aside there was an `urban legend` when I was still serving that worn barrels for the Centurion, Abbot etc were kept for use if the Cold War became a Hot one & that they were packed with preservative & buried - apparently in Canada?
 
If you have reached the point on the machine gun to when it starts to Run-away(You do not have your finger on the trigger anymore and it is still firing) this means that the barrel is melting and now the rounds are being touched off by heat in the chamber. You twist the links down away from the chamber and let it fail to fire. This barrel is worthless and cannot be used ever again. This also apples to open bolt guns as well. The barrel that is worthless should be given back to the armorer from what I have been told. But I know of a GI or two that were in Vietnam that would throw these barrels away in the bushes, wells, rivers & creeks, and so and so forth. This helped the VC to build some kind of booby-traps with it.
 
pointblank0 said:
I think thay still have to be plugged whatever % of the length of the barrel. I would imagine that a worn out barrel would still be more than capable of discharging some rounds. I'm not sure though. There was a post on here earlier on in the year with the scans of the proof house documants to be followed when deactivating, can't remember where they are though.
Click to expand...

Thanks Pointblank - I have seen the new guidelines, but that's where my problem lies - the barrel has to be plugged for a certain % of its ORIGINAL length and mine has nowhere near the required length left, which makes it a cut-down weapon and the authorities seem very unwilling to allow these to be retained - it is a total relic, heavily pitted and more parts missing, but still a section 5! Local police are aware and in the past I have had dug weapons passed locally as no longer being firearms. However now they are not interested as due to cut backs they no longer have a firearms inspector in the County!
 
Just as an example, original manual for MG34 says that if 5 belts = 250 rounds are fired in a very short time ( one burst or so ) the barrel has to be cooled down properly or replaced with a cold one before firing more rounds.
By own experience I can tell the barrel is really hot then.
 
NickW said:
Thanks Pointblank - I have seen the new guidelines, but that's where my problem lies - the barrel has to be plugged for a certain % of its ORIGINAL length and mine has nowhere near the required length left, which makes it a cut-down weapon and the authorities seem very unwilling to allow these to be retained - it is a total relic, heavily pitted and more parts missing, but still a section 5! Local police are aware and in the past I have had dug weapons passed locally as no longer being firearms. However now they are not interested as due to cut backs they no longer have a firearms inspector in the County!
Click to expand...

It appears that nothing is bloody easy!
 
The run-away firing mentioned by V40 was known to me as a `cook-off' or breech explosion, where the heat of the chamber metal is transferred to the cartridge case of the next round in the breech, causing the propellant to burn and the round to fire without the gunner pressing the trigger. I remember there was a published table relating to the 7.62 mm GPMG that gave the time to cook-off depending on how many rounds had previously been put through the barrel within a set time. Cook-offs can and do injure people and as has been said, barrels have to be written off. A good clue for a cooked off round is an apparently fired, empty cartridge case but with no strike mark on its base or even missing its percussion cap.
 
An advantage to avoid this are MG's that fire from open bolt ( cartridge remains in belt/magazine until fed in chamber by bolt and ignited at once ). I have heard that overheated Maxims also suffered breech explositions and caused accidents because the next round already is in chamber waiting to be triggered.
 
Generally, a cook-off will result in a round firing out of battery, shutting down the runaway on its own. The cyclic rates are such that a perpetual runaway, due to an overheated barrel, won't last but maybe two or three rounds. Most often a runaway is caused by a mechanical issue. The early M240s were prone to it if the gas port was not set properly. I'm guessing they've fixed that in the newer models. While MGs are exceedingly fun to play with, I would never trust my life to any of them, if the SHTF. Jams are guaranteed.
 
A friend of mine ran a thousnad round belt, non-stop, through his MG42 (converted to 7.62 NATO). At the end the barrel was glowing red and the barrel was finnished with no rifleing for the first 6 to 12 inches. The conversions were 1919 barrels fitted to the MG42 barrel extensions with an MG3 topcover. In fact he did it on two seprate occasions!!!

I heard a storey from a friend of my fathers who served in the Canadian Army in WWII. At the end of the war he was in the Army of Occupation in Germany. They were guarding an ammo dump and as he told it the "work" was rather boring. To enliven the boredom they hooked up an MG42 on a tripod and linked up all the belts they could fing and started firing. As he told it the MG42 fires 13000 rounds before it "melted down" and quite firing!!!
 
Interesting comments.
Firstly NickW regardless of length of barrel remaining why not just have it 'slotted' down one side. This meets UK spec and as you only have a smal section left it saves all this plugging! Barrels of cse can be re-bored but if the barrel is worn it is still usable, as shotgun for example, so yes in UK an old tired barrel is still licensed. With regards WWI German and British MG barrels, tired barrels remained in service and became DP, blank or wood firing. Both nations marked their 'old' barrels accordingly. For the collector a DP barrel is actually quite a nice find!!
Mark
 
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