303 British Head space

[Theiskell]

Anyone know where to adjust the headspace on a 303 British. Do you adjust it like most guns from the barrel OR was the bolt adjusted to the barrel. I have had conflicting answers on this. Any help is greatly appreciated.

[38_Cal]

If you have a Lee-Enfield rifle, you change out bolt heads. They were numbered (I think) 1 to 4. If you have a .303 in a U.S. made P-14 rifle, you'll have to do a barrel setback and re-chamber...same for a Martini-Enfield in .303 Brit.

David

[bob308]

another way i have read about for the no. 1 and 4. was to build up the bolt face with a shim. i have thought of trying hard chrome. have done it to some winchester 92 and 94. and it worked.

[Theiskell]

If you have a Lee-Enfield rifle, you change out bolt heads. They were numbered (I think) 1 to 4. If you have a .303 in a U.S. made P-14 rifle, you'll have to do a barrel setback and re-chamber...same for a Martini-Enfield in .303 Brit.

David

OK this is good info. The rifle I have is marked “Enfield 191? SLE III*” On the bolt head are markings “M” on the top of the bolt head…..On the side of the bolt head is “MP RF1” I’m not sure if that helps or not . My next question would be where can I find the correct bolt head. I have a go gauge is there a way to determine the correct bolt head I need. Would it be as simple as adding layers of tape to the go gauge until the bolt would no longer close? This was the first gun I had as a child to hunt with. It shot well for many years then all of the sudden I had a problem with the cases separating.

[Theiskell]

Ahhhhh found another mark that was hidden.......Ok ok it was just dirty but it appears to be a 2

[38_Cal]

Are your cases separating with reloads or new ammo? Check your headspace with metal shim stock between the GO gage and the bolt face...tape compresses too much and can give you a false reading. SAAMI print shows a minimum headspace of .064" from the front of the rim recess to the locked up bolt face, with a max. of .071. Normal NO-GO gage distance should be about .068" to .069".

If your headspace gages ok, and you're having problems with reloads, look at your brass, press and dies. Old brass is prone to head separations from over working it. Some dies for .303 move the shoulder back too far during sizing, and this will over work the brass as it blows forward on firing. Try neck sizing your brass, rather than full length sizing it.

David

[Theiskell]

Once again great info. I have always used reloads and full length sized the cases. The brass had probably been fired 4 to 5 times I’m not positive on that since, at that time my father kept the records. It’s been several years since I shot the gun but I don’t remember seeing any bulging or cracks around the base where they separate prior to reloading. I have some stainless shim stock I can use to check the spacing, but you may be on to something. My father was always bad to use brass until he saw failure signs during the reloading process.

[crusty]

Theiskell,

headspace is probably OK if you haven't changed anything. The SMLE No1 MkIII that you have does not have numbered bolt heads so forget that.

Full length sizing is your problem - the chambers are generous on these rifles & the dies are made to SAAMI specs which are rather bogus & too tight. If you want to stop case head separation use the Lee Collet dies - they only size the neck. I have had eight or more reloads out of my brass.

Three reloads out of full length sizing is about all you should expect.

SAAMI head space specs are also wrong. There are a number of Lee Enfield forums around, have a browse through them.

http://www.milsurps.com/forumdisplay.php?f=72

This has the best info.

[chriskat]

Neck sizing using your existing full lenght sizing dies should work as well. Back the die off enough so that you only size down to the base of the neck.

If you don't like that idea measure 10 or so fired cases from the base to a datum on the shoulder and adjust your sizing die so you only set the shoulder back about .003" from the fired dimension. With that done you'll essentially be headspacing on the shoulder instead of the rim.

Jeff

[crusty]

You won't see cracking or bulging, but you might see a bright ring which is a sign of the brass stretching. Get a paperclip, straighten it out & then bend an "L" about 1/8" long on the end. Carefully drag the "L" along the inside of the case near the head & you should feel it catch where the brass is thinning - there will be a slight groove. If you feel this, the brass is no longer useable - throw it out.

Have a read of this, ignore the smartass stuff, but Ed knows what he is talking about. see post #25 & you will understand exactly what is going on.

http://forums.gunboards.com/showthre...ght=separation