In all probability your rifle will have a chamber reamed as specified. It will be a military chamber. I expect you have inspected fired cases, and know whether there is any hint of incipient separation resulting from excess headspace, expansion in front of the solid web, or shoulder fireforming forward.
LE No4 bolt head timing to bolt
- Thread starter I Dont Care About You
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In all probability your rifle will have a chamber reamed as specified. It will be a military chamber. I expect you have inspected fired cases, and know whether there is any hint of incipient separation resulting from excess headspace, expansion in front of the solid web, or shoulder fireforming forward.
First set above are SAAMI specs for Go/NoGo/Field
Armorer spec for 303 Brit is
GO 0.064
FIELD 0.074
Woodchopper 0.074 is Field. They didn't have a NoGo
The Instruction for Armourers 1931, PART II Small Arms, Section 3 -- Examination / The War Office 1931
"4. Action: Bolt and bolt-head.
(i) Test the distance of the bolt from the end of the chamber with gauges .064-inch No. 1 and .074-inch No. 1; the bolt should close over the .064 but not over the .074; when using the latter gauge, light thumb pressure only should be applied to the knob. Also test to see that the wing of the bolt-head does not lift off the rib of the body."
NOGO would have come later via SAAMI and others to better evaluate headspace.
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Something else to consider if minimum headspace is desired...
Cartridge rim thickness can vary with manufacturer.
It would be worth checking the rim thickness of cartridges used. If they are on the thin side, efforts to minimize headspace by swapping bolt heads might be less productive.
A block or plate could be made with a close fitting hole into which a cartridge could be dropped. Then a depth micrometer or decent caliper could be used to measure rim thickness.
Cartridge rim thickness can vary with manufacturer.
It would be worth checking the rim thickness of cartridges used. If they are on the thin side, efforts to minimize headspace by swapping bolt heads might be less productive.
A block or plate could be made with a close fitting hole into which a cartridge could be dropped. Then a depth micrometer or decent caliper could be used to measure rim thickness.
- Location
- Western Manitoba
At least the 303 British gives one the option to transfer end play to the case shoulder from the case rim - if reducing that much end play makes a difference. I have a new-to-me 300 H&H - from reading, it said that the case shoulder is too shallow angle for headspace control, so pretty much have to use the belt - which I see SAAMI defines as minimum .220" and maximum .227" for the chamber cut - so .007" variance within SAAMI compliant standard. I have a selection of brass for it - I suppose one could gauge or measure the distance from rear case face to front edge of belt - sort through to select ones that match to the chamber cut in this rifle?
Although, I see SAAMI calls out .220"-.008" for the cases, so is not likely to find many that are longer than that spec? Meaning, that SAAMI is okay with a .212" belted case being fired in a .227" chamber cut (extreme ends of their compliant tolerances). It might be possible, though not something that I will likely try on this Win Model 70, to get the headspace cut in the chamber to minimum .220", but then about pointless, if the belted brass to be used, can go down to .212" dimension.
Although, I see SAAMI calls out .220"-.008" for the cases, so is not likely to find many that are longer than that spec? Meaning, that SAAMI is okay with a .212" belted case being fired in a .227" chamber cut (extreme ends of their compliant tolerances). It might be possible, though not something that I will likely try on this Win Model 70, to get the headspace cut in the chamber to minimum .220", but then about pointless, if the belted brass to be used, can go down to .212" dimension.
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The military never worried about reloading it's brass, but that may change with the Trudeauites continued neglect. 50 yrs ago I got a pi$$ pot of DA 55 .30-06 that fell off a truck somewhere and some of it is on it's 5th reloading cycle.
"Trudeauites" I think you mean "TRUDDITES" which are extreme left LUDDITES.
The belt will headspace the case for first firing, just like the 303's rim. Then you can neck size as required. The 300 H&H has a shoulder, just a very long sloping one. The 303 chambers are all over the place. In surplus rifles, Ross had the tightest chambers of any I owned, though some of those were rechambered for more realistic trench conditions as well. - dan
So .......... I just know the following is gonna garner a whole bunch of, "I told you so" comments but IMO lessons learned first hand are the most valuable and I'd always rather find out for myself than blindly accept, "Everyone knows" kind of information.
I bought a lot of new, unissued LE No4 bolts and had several different bolt heads to experiment with and find out how my rifle headspace is.
The majority of the different bolt and bolt head combinations I tried did not improve the headspace the rifle was made to. I found one bolt that is identical to the bolt the rifle came with. I found another bolt-head combination that has a slightly shorter headspace with the NOGO gauge. However that bolt combination would not close on the GO gauge. It would nearly close on the GO gauge, meaning it is only slightly long.
I'm gonna keep the long bolt as a hedge against stretch / wear of the OEM bolt. I may even give it a try with some of the commercial cases I've got to see if it will close on those cases. It would be beneficial to fire from the cases using the tighter headspace bolt and then switch back to the OEM bolt and just neck size cases after that. Of course this is dependent on the bolt closing on the cases.
In the end, I now know how a LE closes or not on a headspace gauge. It is not at all like a modern rifle, which will generally come to a hard stop on the NOGO gauge. The LE action can easily be forced closed on the headspace gauge. Thus the feel of the gauge is important to understand.
I bought a lot of new, unissued LE No4 bolts and had several different bolt heads to experiment with and find out how my rifle headspace is.
The majority of the different bolt and bolt head combinations I tried did not improve the headspace the rifle was made to. I found one bolt that is identical to the bolt the rifle came with. I found another bolt-head combination that has a slightly shorter headspace with the NOGO gauge. However that bolt combination would not close on the GO gauge. It would nearly close on the GO gauge, meaning it is only slightly long.
I'm gonna keep the long bolt as a hedge against stretch / wear of the OEM bolt. I may even give it a try with some of the commercial cases I've got to see if it will close on those cases. It would be beneficial to fire from the cases using the tighter headspace bolt and then switch back to the OEM bolt and just neck size cases after that. Of course this is dependent on the bolt closing on the cases.
In the end, I now know how a LE closes or not on a headspace gauge. It is not at all like a modern rifle, which will generally come to a hard stop on the NOGO gauge. The LE action can easily be forced closed on the headspace gauge. Thus the feel of the gauge is important to understand.
Well it led me back to where I started, but I learned some stuff in the process and now I actually know the headspace is correct, or correct enough in my rifle.
- Location
- Western Manitoba
You might come across that odd "feel" with the headspace gauge, if you try to check headspace on a P14 - that one was re-named as the No. 3 - was also designed at Enfield Armoury - so it had helical breeching, like the Lee Enfields - the bolt goes forward all the time the bolt handle moves down - so only place to get an accurate reading is the "feel" as the bolt handle hits it's stop on closing - many modern rifles, Mausers, etc. - the bolt stops moving forward when bolt handle only part way down - as you describe, a much different "feel" to it, due to the tremendous pushing forces that the various Enfield bolts can apply when closing.
The No. 4 has that replaceable bolt head - the P14 does not - so the "feel" might also be some "squishing" going on as the bolt head thread maybe crushes a bit on the No. 4 - as the head comes into firm contact with the bolt body - won't get that on a P14.
The No. 4 has that replaceable bolt head - the P14 does not - so the "feel" might also be some "squishing" going on as the bolt head thread maybe crushes a bit on the No. 4 - as the head comes into firm contact with the bolt body - won't get that on a P14.
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I also suspect the squishy feeling on a LE is a result of the longer distance from the bolt face to the locking lug. Modern rifles have the locking lugs right behind the bolt face so there is nothing to squish or move or compress. Thus the bolt handle has a hard stop when it hits the headspace gauge.
As many 303 Brits I have had I already knew the end result just from what I have experienced from different rifles and how they function. Biggest problem I see is everyone of them has a chamber that is slightly different from the next one. Hence why most people neck size. Too many people stress out on the head space on LE’s. They are what they are.
