303 Brit, bad brass or rifle issue?

flying pig

flying pig

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I have two Enfield rifles, a No1 MkIII and a No4 MkI. Was target shooting remmington core lokt 180gr in the No1 MkIII and federal powershok 180gr ASC load in the No4. I do not have head space guages for these rifles yet, I am planning on getting go, no go and field guages after Christmas. Both rifles shoot very good groups, and the No4 has only shot about 30rds since being converted to a sporting rifle by Parker-Hale post war. The brass is kind of kinking near the base where the clearance in the chamber starts on both rifles, 1/2"ish from the rim. Its only does it for around half of the circumfrence. No light color spots or anything like I have read about with headspace issues. Junk brass? Any other ideas? Both rifles do the exact same thing, and I shot both ammo types in the No1 and samne result.
 
Generous chamber dimensions allow the brass to expand near the solid head section when the cartridge is fired.
This is a normal situation. [ not junk brass ]
Chambers are usually quite generous in dimension on these rifles.
The reason it is not all the way around the base is: the cartridge lays on the bottom of the chamber.
When it is fired, the case does not automaatically center itself, but remains in contact with the chamber wall at the bottom.
The case expands upward, and to a certain extent, sideways to fill the slightly oversize chamber, and that is what you see when you extract the fired case.
FL sizing shortens the life of this brass, so a neck sizer is a better idea if you reload for them.
Regards, Eagleye.
 
its the fact its remington brass all of the brass like remington,winchester,federal has a groove by the rim the brass likes to flow into this groove with the lee enfield a oring on the groove will help when firefroming this makes the brass head space on the shoulder you will need to neck size only

its hard to explain but heres something that should help
2v2gswz.gif
2u5z31t.gif
the is how case head separation starts in the lee enfield

this is the oring to help
headspacestretch_frame_0001-1.jpg
fireformedzeroheadspace-1-1.jpg
you will have to neck size and keep cases sorted for each gun(cant inter change them from one gun to another when neck sized) full length resizing will set the shoulder back resetting the gap in head space
 
So basically using the oring to hold the case back against the bolt allows the brass to custom size itself for that particular rifle? Kinda like how Hatcher talked about slamming the action on a given rifle shut vs closing it gently...

Just use a small thin oring then?
 
flying pig said:
So basically using the oring to hold the case back against the bolt allows the brass to custom size itself for that particular rifle? Kinda like how Hatcher talked about slamming the action on a given rifle shut vs closing it gently...

Just use a small thin oring then?
Click to expand...

oring that fits tight on the case
 
The expansion ring on .303 cases can be more pronounced than with other calibers because of the generous chamber dimensions. If the head looks off center, sometimes this is because of the case wall being thicker on one side than on the other. Often firing pin strikes are well off center. Doesn't mean anything, other than the axes of the bolt, cartridge and chamber don't line up perfectly. As noted, fireformed brass can be treated as if it were rimless in order to prevent unnecessary working of the brass.
A good thing about .303 is that if a separation does occur, there is generally no release of gas.
I have observed a problem loading brass fired in Lee Enfield for use in my Ross II** target rifle. When the brass is full length sized, it is still too large in diameter near the head to chamber in the tight Ross chamber. I made an additional sizing die which takes the case diameter near the head back down to new dimensions.
The o-ring trick is useful in other situations. I am fireforming .348 Winchester brass for use in a Type 18 Murata 11mm rifle. Base and rim diameters are fine, but the rim is on the thin side. Not much shoulder to hold the base against the bolt face, so a spacer can do the trick.
 
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