Clues From Fire Formed Brass - 303 Enfield

[josmund]

I have a new to me Enfield Mk 1, lll*. It's a 1918 BSA version which was reworked sometime over the past century.

The bore looks great but I was worried the chamber may be eroded. I shot a box of factory brass and the measured the difference from the spent vs factory cases.

They are identical in length. The neck was opened as expected, The body was the same diameter above the rim but opened up .004 right before the taper to the neck.

I don't have much experience here but this seems like a pretty good indication the chamber is within specs. Can I tell anything about head space by brass which does not grow in length? Any other thoughts?

Thanks

 

[jaguarxk120]

Many Enfields have a chamber that is sloppy or large.

Don't forget the British Army did not care about reloading.

Whit a overly large or longer chamber when firing the case gripps the chamber and the head is forced back against the bolt face. This action stretches the brass just ahead of the rim.
That's why there are case head separations on first or second reloads. You can check for this stretching with a paper clip bent with a small hook feeling the inside of the case.

One solution is to place a "O" ring at the base of the shell forcing the base against the bolt face. That way the case will fire form properly.

 

[WelshShooter]

The Lee Enfield chambers are very generous. I believe the purpose for this was that you could effectively fire "dirty" ammunition so you didn't have to worry about your so much if your ammunition had mud, grit, dirt etc on it. The downside is that the brass does stretch a lot for handloaders and is very prone to case-head separation as jaguar has pointed out.

You might want to get your headspacing checked by a competent gunsmith as the Lee Enfields are notorious for losing headspace over time because of the rear locking lugs. I have a No4 MkI and had to swap out the bolt head because my headspace was too large. The shoulders of fired brass would jump out way too much. When I swapped the bolt head for the next size up I didn't get any problems.

 

[josmund]

Thanks for the feedback
If I've shot 20 rounds and the cases are nearly identical to factory ammo, does this not tell me had spacing and the chamber are good?

 

[WelshShooter]

It would indeed, but checking with go/no-go gauges is easier! Also, if your brass looks identical to factory ammo I;d say that you would have a very good chamber indeed. The shoulders on factory brass are very short and tight, whereas on fired brass the shoulders have a longer taper as shown in the image below:


FYI, these aren't my images. Stole them from Google.

 

[GooseGestapo]

I recently acquired a Fazerkerley #4MkI. It has obviously had a rework and has a splendid barrel and chamber. With my exploration of loads and bullets, I'm using BLC2 to load factory equivalent at ~15% less pressures and H4895 for cast bullets for practice. I intend to use it for vintage military matches. With my added Fazerkerley milled rear vernier sight, I'm set. Can't say I enjoy shooting my Garands more than the Enfield. To match it, I was given a Webley MkII with a shaved cylinder (accepts .45acp In moon clips- yeah I know- 3.0gr of Bullseye w/200gr SWC...). The Limeys were well armed!!!
It's ~ 2moa with 150gr Hornady PtSpts and 150 gr PPU JACKETED. Even better with 174gr Hornady BTHPT match bullets.