Yesterday I took my M60E6 out to shoot, and I had a broken shell. It is stuck in the chamber. I'll be ordering a broken shell extractor tomorrow. This is the second time that I've had a broken shell. The first time I used a small hooked screwdriver to get it out. This time it is stuck and needs a broken shell extractor.






I went home and was cleaning the cases, and I noticed I had other cases that were about to separate. I reload, and this is my third time through this batch of 308 brass.




Does anyone have a hypothesis as to what is causing this? I don't think that it is excessive pressure, as I am within the range of the powder manufacturer (although admittedly on the higher end).




Is this something that is a common occurrence in open bolt guns?





 

Case head separations are caused by brass getting stretched while shooting.  In a bolt gun with a nice tight chamber, you can fire casings over and over (assuming you are resizing them the minimum amount needed for them to chamber freely) because the brass doesn't stretch much each time.  Military rifles are made with "generous" chamber dimensions for reliability.  Troops can't be using a gun that will quit because a grain of sand or two got into it.  These oversized chambers cause the brass to get stretched a lot when fired, so the useful life of the casing can be only one or two loadings.

I experimented with a small batch of brass fired in a WW I Lewis gun and started getting case head separations after two reloads.  You have to remember that the military doesn't give a damn about reloading fired casings, so if it makes it through the gun once with great reliability, they're happy.

With the separations you have showing up, it's time to scrap that batch of brass.

So the solution would be to replace the barrel with one that has tighter dimensions?

You should check the headspace and barrel erosion. Provided you are using good ammo chances are high your barrel is due for replacement.

Sometimes changing the bolt can correct it but you would need a test bolt and headspace gage to know for sure.

A tap will get it out.

Well, that's one possible solution.  Considering that M60s were all built for military use and the barrels have Stellite inserts, it would be kind of expensive to have a custom barrel made up just to prolong brass life.

As mentioned, you may have an excessive headspace (even by military standards) situation going on.  It may be time to change out the barrel and/or the bolt.

Or you could switch to cheap steel-cased ammo, pick the casings up with a magnet, dump them in the trash and not worry about reloading.  

Well what you need is one of these:











Guaranteed to remove a case separation.





But as for reloading goes, I have reloaded upwards of 50,000 rounds for my ANM2 beltfed (30-06) and have found that  not counting the original load, best case for reloading the brass is 2 more times.  This will result in about 1 case separation out of 600 rounds.  Reload a third time, and you will have a minimum of 2 case separations per 100 rounds.  And it really goes down hill after that.  Now you will experience more separations if your barrel is shot out.   If your only on your second re-load, then I would suspect barrel erosion beyond acceptable levels.  They do make .30cal gages to measure the erosion.  





I would try a new barrel.





Good luck
   

 

Anm2, what is that a pic of? It is not loading on my screen. Do you have a link to the item? I was told that a normal case puller won't pull out the separated case.


Your ratio makes perfect sense.i am getting about 1 separation per 100 now, it seems.


I spoke to a former military armorer today. He said that the M60 has a fixed headspace, so it's probably not the headspace. Most likely, it is the result of reloading MG brass on an open bolt gun. He says two reloading a max per case. Open bolt belt fed guns like the M60 violently extract the case while it is hot, thus leading to a shorter lifespan for the brass. Also, he said that the chamber is looser, as stated above.




I've shot about 20,000 rounds through this barrel, which for this barrel, shouldn't be that much. I purchased five of these E6 barrels new.


 

I only shoot brand new Federal Lake City M80 through my M60E4 and never have this issue.

With  M60s you need to be somewhat careful on the ammo you use as if you get a case separation like that that dislodges the extractor out of the bolt you can lock the bolt into the barrel extension.  The M60 doesn't have much in terms of egress to the internals unlike other machineguns like the M16 where the whole top half comes off via pushing out two ping.

The only fix if you get a bolt stuck in the extension due to bad ammo is to try and beat the bolt out via the op rod via the front of the gas block (after removing the piston) and if that fails to put the gun in a mill and cut the bolt in half forward of the op rod yoke, allowing you to extract the barrel out the front of the gun with the bolt still stuck in the barrel extension.

As the other posters have mentioned, military barrels are on the looser edge of spec for reliability, which equals a lot more stress on the brass and is probably leading to the head case separations you are seeing on reloaded ammo.

Edited to add.  M60s have fixed headspace when they are manufactured.as the headspace is set between the barrel and the barrel extension at the factory.  M60s  are not like a M2 or 1919 where you set headspace each time you install the barrel.    However headspace on an M60 will change as you get erosion in the throat and the barrel extension socket to some degree.  20,000rds on any single barrel (even a stellite one like an M60) is a lot of wear and tear.    I get less than half that out of chrome lined M16 barrels.  I would certainly get a set of go/nogo gauges to confirm  if headspace is still in spec on a barrel with 20K+ rounds down the tube.

Fortunately, I have a lot of spare bolts and barrels. I still want to find a way to pull out the broken case and rescue this barrel. They aren't cheap, at like $800 each, new.



I really didn't think that 20,000 rounds was that many rounds.






It is going to hurt to throw away all that 308 brass. I have around 10,000 that is going to hit the trash. That's gonna be terrible, but I'm going to do it.










 

The barrel may very well still be serviceable after 20,000 rounds.  A lot is going to depend upon how much abuse it saw. (i.e. are you regularly dumping 100rd belts, letting it cool between belts by swapping it out,  firing in small bursts, etc.)  A set of headspace gauges will quickly help you determine if the barrel is still in spec headspace wise.

However, you are going to get some throat erosion every time you pull the trigger.  A barrel with 20K down the tube is going to have more throat erosion than a new in bag barrel.  This may still be fine if you are using new brass case ammo, but take a barrel with 20K worth of throat erosion and brass that has been through a machinegun 2 or 3 times and you have the recipe for head case separation you are seeing.

Reloading can save you time/money but when you are talking about US Ord M60 parts cost  it doesn't take many wrecked or damaged parts to quickly start negating the reloading savings.  (not to mention the headache of a jammed up gun)

Guns like M16s where a whole new upper is less than $500, a barrel is sub $200, and anybody with two opposable thumbs can fix it in the field/range by dropping a new upper onto the gun the economics may make more sense to run reloads/steel case/ or surplus.

I would be surprised if the brass couldn't be removed from the barrel.  It may just require sending it out to somebody who has the knowledge and tools to get it out without damaging the chamber or stellite throat insert.

Scrap the brass, don't trash it.

Yes 2 reloads would be the max I would expect before the cases were in need of replacement. That gun is hard on brass.

ive had this happen. broken shell extractor is mans best friend. i load ammo three times. thats it. and thats counting the first firing if
it was factory loaded. i did find backing off the die to help this greatly. it doesnt work the brass as much.  you can back off the die slightly and test the brass with a bolt
and fitting into the barrel socket. to where its not tight.

the brass piece will pop right out with the shell extractor. its very easy to use.

 
 

I own head space gauges for all my center fire machine guns. It is always a good idea to keep track of head space in guns that in several cases are near 100 years old.



MG chambers also tend to be on the large size as well as head space so it works the brass pretty bad. I would not reload brass more than 2 times.

I ordered the Brownells broke shell extractor. It was completely useless.


I'm sending the barrel to an armorer to have the broken case extracted.




I've learned my lesson. Two reloads max on a belt fed. Good lesson to to have learned now, as I have a pair of beltfeds incoming.


 

weird, i never had an issue. brass would pop right out.

That's what I thought, too. The first time I had a broken shell, it came out with a hooked pick. This time it was stuck good.


I've already sent the barrel back to the armorer. I've asked him to sell me a special broken shell extractor, in case this happens again.


 

did you have the tool that you put into the barrel socket and close the bolt ?

Yes. I closed the bolt on it, and it wouldn't catch the front of the neck. I ordered it from the Brownells website.

I tried for a good hour or so. At the end, the charging handle got stuck. I'm guessing the charging handle was stuck because the broken shell extractor was finally able to engage the case neck. But the handle would not pull back no matter how hard I yanked the charging handle. Not wanting to bend the charging handle, I then pulled the barrel off the M60. After applying considerable force, the barrel dislodged from the gun, but the case was still stuck in the barrel.


I just gave up and sent the barrel back. I also sent the gun back to have it checked.

With that kind of shell extractor, I find it safer to use a range rod to tap on it from the front once it has engaged the broken shell instead of using the bolt and charging handle to yank on it.  Usually the broken piece pops right out but it sounds like you have one REALLY stuck in there.  The only other thing I can suggest in a case like this would be to pull the barrel and submerge the rear end of it in penetrating oil like Kroil for a day or two, then heat the chamber area with something relatively mild like a propane torch before trying the shell extractor/range rod again.

Agreed I personally wouldn't use a broken case extractor to remove stuck cases that requires closing the bolt on the case extractor tool for the very reason that you could end up with the gun locked up if the case remnant wont come out.

Pull the barrel, insert the tool into the stuck case and than use a dowel down the barrel to gently tap it out.  Worst case if the case still wont come out at least you don't have the breach locked up.  

On a 60 it is a bit more critical since you really don't want to  yank back hard on a stuck charging handle since the portion of the receiver channel that support the charging handle is just sheet metal and really not designed to take much lateral force and can be damaged if too much force is applied.