Over-length chamber in 1917 Lee Enfield?

MD

MD

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I just compared a couple brass cases I shot out of my buddy's 1917 BSA Lee Enfield with some unfired cases and found that the shoulder was about 3/8 farther along the bass case on the fired ones than the unfired ones.

Not only that, but there is a noticeable ring around the brass about 1/4 inch up from the rim and one has a noticeable split in it.

On the left side of the barrel it is stamped:

Crown
X
P

(something small) 17 on the reciever it says

Crown

GR

X

P

On the right side it is stamped:

E
72429

And on the barrel it says: 303" 2.22

On the metal between the pistol grip and the for end wood it says:

Crown
GR

BSA Co.

1917

Sht. LE

III *

Is there anything unusual about this rifle?

Why does it have such a long chamber?
 
Yep, your headspace is too long.

Nothing unusual for a Lee Enfield, a lot of them had generous headspace when they left the factory. It's a 94 year old rifle, so it should come as no shock that something is out of spec. Someone may have swapped out the original bolt head for something shorter withot knowing it... maybe it came that way from the factory... or maybe it has seen a lot rounds, who knows.

You will likely need to take it to a smith and have a new bolt head installed and the headspace checked. If that won't fix the problem, a new bolt may be in order. Should be about $5-$20 for a bolt head or $35 to $40 for a new bolt, depends on who you ask and what size you need.

Or if you have a set of vernier calipers, easy access to a number of different sized SMLE bolt heads, and some headspace measurment tools, you can do it yourself quite easily.
 
Your headspace may be loose...not a shock on an old SMLE.

But, aside from that, the chambers were long and loose anyway so the rifle would function no matter what was encountered. Picture the mud in Flanders, on your ammo.

I've shot No 4 Enfields(much newer), when you fired them the shoulder on the brass moved well forward.

Nature of the beast.

Definitely worth checking headspace though.

BTW, on a 1950 Long Branch No 4 I had, the chamber was the tightest I've seen. The brass barely changed on firing.
 
Headspace too long?

I often wonder just how much people know about headspace. Headspace too long? Doubtful for sure.

The .303 British headspaces on the RIM. Therefore, to get a shoulder 3/8 inch longer than a factory case, there would have to be 3/8 of an inch of headspace. A doubtful condition to be sure.

Wartime Lee Enfields had generous chambers, and some were even reamed out longer to compensate for the mud of trench warfare as has been mentioned. Ross rifles marked with an "E" for enlarged chambers or "LC" for long cone are capable of blowing out the brass like your rifle did.

Many splits in cases are caused by a defect in the brass case, or possibly a gouge or dent that weakens the case.
.
 
Buffy, you beat me to it!
Many people are pretty fuzzy on what head space is all about.
All Lee Enfields were made with lots of room in the chamber, like has been said, so dirty ammunition will work fine.
The ring mentioned above the rim, could be from too much headspace, but could also be caused by the generous chamber of the rifle, allowing the case to expand considerably, just above the solid web, or a combination of both.
 
Headspace

buffdog and H4831 are right on the money.

If you have a shoulder that has moved ahead 3/8 of an inch, there is another reason for it.

I ran across a No1 MkIII* that had been rechambered to 30-40 Krag. I have no idea why. They are almost identical in power.

3/8 inch would be about right if the chamber is 30-40 Krag.

Rifles with rimmed cartridges, headspace on the rim, not the shoulder as mentioned above.
 
That said, gentlemen, if the rifle is separating its brass, there is ANOTHER problem. This problem could be with the brass or with the rifle.

The extra expansion at the FRONT is a non-issue and quite normal on Wartime rifles. Remember, starting about the middle of 1916 ALL Lee-Enfields were made with a LARGER CHAMBER. This wasn't advertised a lot because it was the ROSS that the Brits were trying to get out of Service, but both rifles had problems with a combination of mud..... and grossly-oversized ammunition which never should have been accepted for Service. So the ROSS was reamed and well-advertised as such, the LE also got a new chamber and was marked, rather discreetly, LC, up at the base of the rear-sight bed, on the barrel.

Expansion at the REAR end is somehing else, though.

ALL brass expands UPWARDS in the chamber when it is fired. This is because Mr. Gravity doesn't take coffee breaks; he's at work all the time. So you get some expansion there, vertically,just above the web of the cartridge. If you're not doing something silly (such as firing .308W ammo in a .308NM chamber..... and don't laugh..... I've seen it done!) this expansion will be minimal and harmless. Big Ed has written a couple of excellent posts regarding his innovative use of an O-ring to control both this AND headspace issues simultaneously.
But if the rifle is separating cases, then likely you have a headspace issue or else a batch of bad brass. Bad brass (much too hard) was very common on a certain brand of Canadian ammunition about 30 years ago, but that issue got looked-after, although not without a great amount of screaming and many threats toward the guy who made the issue public (myself). The headspace issue can be controlled with Ed's O-rings and neck-sizing only, then segregating the brass for that rifle, OR by giving the rifle a properly-fitting bolthead. The only cure for bad brass, though, is to trash it.

Hope this helps.
.
 
smellie

smellie, I will bow to your explanation about chambering and headspace. I agree with all of it.

Do you not think the 3/8 in forward movement of the shoulder was excessive?

Personally, I've never seen a chamber that oversized. 3/8 in would indicate some serious problems if he's getting case head separation as well.

If his bolt head is that much out of spec or the lugs are set back that much, there is a good chance there will not only be head separation but escaping gasses and bits of metal.

Either the OP isn't giving us enough information or I'm really missing something here.
 
A question for smellie... with regards to these "hard brass" cases, why not just heat them up red hot to anneal them? Wouldn't that work? Save the lad some coin...
 
My bad.

Of course, that's why the neck area of cases are discoloured... they only anneal the neck so the bullets can get the f$%# out of there when it goes bang. Hard brass in the base to contain the pressure better.

Got it... (you can tell I don't handload).

As you were.
 
"Either the OP isn't giving us enough information or I'm really missing something here. "

What else can I tell you?

It was Federal brass that I hear is weak.
 
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