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Worn breech

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Category: Enfields
Forum Name: Enfield Rifles
Forum Description: Anything that has to do with the great Enfield rifles!
Printed Date: June 05 2023 at 6:29am
Software Version: Web Wiz Forums 12.04 -

Topic: Worn breech
Posted By: Jturn
Subject: Worn breech
Date Posted: March 17 2023 at 5:23am
New to Enfield Rifles, and this is my first post. I recently bought my first Enfield, it appears to be a 1943 B.S.A. dispersal SMLE. I’ve been watching as many videos as I can. Trying to do as much online research as I can before I shoot it. I found a video where the man shows how to check the crown and the breech using an unfired round. By this estimate my crown seems great, but my breech seems worn, as the round drops right in (bolt and mag removed...without having to push within my finger). Is this common? Is this safe? Thanks in advance for taking the time to help!!

Posted By: Goosic
Date Posted: March 17 2023 at 1:31pm
The chambers are very generous to allow for dirt and debris in battlefield conditions so, for you to have a cartridge fall into place is quite common...

Posted By: Jturn
Date Posted: March 17 2023 at 2:00pm
Thanks for the reply!

Posted By: Shamu
Date Posted: March 17 2023 at 4:40pm
Both tests are more folklore than science!

"The bullet test" depends heavily on the individual bullet contour. One can go in a long way & the other barely at all. It also ONLY checks the crown. Many will tell you its a test for the bore but that's nonsense. For the test to be valid you need a specific single bullet to use as your gauge. Not one similar to another out of the same box, but one exact one. Even then it's an implied measurement, not a solid one.

"Chamber Test" This one opens a whole can of worms. Some things to factor in.
HEADSPACE: The drop a round in won't tell you anything about it at all. The case is rimmed & you have to separate the methodology for Rimless from the one for Rimmed. A lot of stuff has been posted where the two of them have been merged & used where not applicable.

A rimmed case headspaces on the space between the standing breech & the bolt face. NOWHERE ELSE. That's why it measurements are so short compared to rimless cases. 0.067" for the .303 British being "perfect" but anything between 0.064" & 0.074' being "acceptable" (there's also an even sloppier 0.080" "wartime expedient" emergency one allowable! Nothing further forward into the chamber is headspace!

Now there are "chamber variations" & "Generous Chambers".
The case is tapered & the shape of the shoulder taper & neck junction can all vary too. Its also, as has been mentioned "generous" to allow dirt to not bind up or prevent chambering of muddy or corroded ones.

Rimless cases use a "datum line", much further forward, usually the mid point of the taper to the case neck. For them the Headspace is from the closed locked bolt face to this datum line. example 7.62/.308 has a 1.6355" to 1.6455" range.The chamber shape & length to the neck & shoulder are also standardized.

Got a headache yet?
Evil Smile
Now some shooters intentionally set the brass of rimmed cases to contact the taper of the chamber, supporting the round by "wedging" the case between the standing breech & the tapered section. It does have some advantages like longer brass life & better alignment in the chamber. BUT there is no "Datum Line" & no single defined contour, so its a unique hand-fit to that exact chamber only.

This is why many Lee Enfield reloaders ONLY neck size their brass. Not full length.

Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)

Posted By: Jturn
Date Posted: March 18 2023 at 2:58pm
Yes, that does sound like a lot!! 

Posted By: britrifles
Date Posted: March 19 2023 at 12:33pm
Those so called “checks” really won’t tell you anything about how the rifle will shoot. Yes, if a .311 bullet gets swallowed up in the muzzle all the way to the cartridge case mouth, it probably won’t group well. 

Dropping a cartridge into the chamber doesn’t tell you anything either, except that there is no obstruction in the chamber.  It should drop in, and is stopped by the rim contacting the back of the barrel.  As Shamu said, the .303 cartridge headspaces on the rim.  Rimless rifle cartridges headspace on the shoulder. 

Probably worth getting headspace checked out, unless you already know it’s good. The serial number on the bolt should match the serial number on the receiver.  

Posted By: A square 10
Date Posted: March 20 2023 at 7:59am
welcome to the site , 

Posted By: Jturn
Date Posted: March 21 2023 at 11:21am
Thanks for the welcome and information! I was able to fire off a few rounds Sunday evening. It was very accurate at about 30 yards and the spent cartridges looked really good. I hope to be able to put it through more of a test this weekend!

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