Cracked 303 casings?

[MD]

I was just looking at a couple spent cases from when I went shooting with a neighbour's 303 # 4 Lee Enfield a while back.

Both cases look much brighter than the rest of the brass in a ring about 6 mm just above the rim and have a prominent ring at 8mm up the case.

One is even partially cracked in a ring parallel to the rim at 8mm.

What the heck?

This was commercial federal loads.

 

[sarge]

Cheap brass, it's good you didn't get the case stuck. Incipient case head separation ?

 

[David K]

.. It's a common occurrence with Lee Enfields. Not all that common with Factory Ammunition, but common with reloads. The British Military recognized the "Problem" and created" a "Stuck Case Extractor". ( Case Separation ) ... Possibly Head Space being at the Max.allowable making a major contribution to the "problem !.....David K

 

[John Sukey]

There are good cases and not so good ones. The ring near the base is common, but cheaper brass with thinner walls can crack there and in other places. I don't see cracks with HXP or Privi Partizan. Also note that Federal has thinner rims and the ammo headspaces on the rim.

 

[brownie]

the problem is caused by the over sized chambers in these rifles. they were built like that so they would work in the dirt and mud and with ammo built to loose tolerances. if you are reloading just size the cases 2/3 of the neck. this will help the cases last a little longer. the best fix if you shoot your .303 a lot is get it rechambered. I have had a couple done the cases look normal after being fired and last longer. I can,t tell you how long until I shoot them some more this summer.

 

[5440fight]

Sounds like a headspace issue, as posted above. Being a no4, check the bolt head size. If it's a #1 or #2, you can find a head next size up and see if the fixes the issue. These rifles were designed with generous clearances to ensure reliabilty in muddy conditions, but use causes compression of the bolt and stretching on the chamber side over time. Using better brass will minimize the issue, and "fireforming" and reloading for this specific rifle using techniques listed in detail in the milsurp section will probably allow safe use even if a longer bolt head is not available. Don't panic, anyone with Lee's has been down this road.

 

[TCBF]

The Lee Enfield was adopted as a SERVICE RIFLE. A service rifle is basically a club with a hole rifled through it, that can be fitted with a bayonet. It was adopted to serve anywhere over a planet-wide empire, hot and cold, rain or shine, fair weather or foul, using one type of ammunition for all conditions.

The cartridge case itself survived the transition from black powder to nitrocellulose. The rifle itself served seventy-five years frontline general issue service by it's developer, and continues to serve in secondary roles still.

It was intended to be a reliable, rapid firing rifle capable of battlefield accuracy. Where greater accuracy was needed, rifles exhibiting the necessary characteristics were selected and 'tweaked'.

They were never designed for reloading, they were designed for battle.

If we want more, we 'tweak'.

 

[sunray]

"...One is even partially cracked..." Cases hard to extract too? Cracked cases is one indicator of bad headspace. Your neighbour needs to have the headspace checked. Even if the serial numbers match. That is no guarantee of good headspace. Thousands of both models of Lee-Enfield have been assembled out of parts bins with zero QC.
"...a head next size up and see if the fixes the issue..." Without checking with headspace guages, just changing the bolt head, one number up, gives no guarantee it'll fix anything.

 

[smellie]

This is definite casing failure, caused by an excess-headspace condition. That much is definite, but it is entirely possible that there is NOTHING amiss with your rifle.

Check the RIM THICKNESS of the brass. Proper rim thickness for the .303 is .059" minimum, .063" maximum. Rims which are too thick won't chamber properly, rims which are too thin will automatically give you an 'excess headspace' condition, even with a perfect rifle. Personally, I have encountered commercial brass with rim thicknesses as low as .037": an automatic .026" OVER TOP OF whatever the rifle itself would do with perfect ammunition. This is a recipe for case separations, pure and simple, being almost three times the maximum tolerance allowed for the rifle, very near NINE times what the Americans allow for a Springfield. And you can buy it right out of a box, at your local store, simply because "everybody knows" that Lee-Enfields are sloppy.

What the Lee-Enfield ACTUALLY is, is likely the single most ammunition-tolerant rifle ever constructed! It HAS to be, just to function with some of the junk which people put into it!

Always check the cheapest item first in any failure of a complex system. It always is the cheapest to make and very often the most likely to early failure. A Lee-Enfield rifle would cost the guts out of $1,200 to make today, using the original methods; the cartridge casing is still under 50 cents. Guess which one is more liable to failure.... and to be out of spec?
.

 

[5440fight]

Good post Smellie, I never knew there was so much variance in rim thickness. How does that even happen? You'd think it would measure up to be .303 British or it wouldn't. That much variation is very sloppy for an application as critical as ammunition.