Enfield bolt head help!

[fatelvis]

I'm trying to identify which number bolthead I have on my #4 Mk1 rifle. The only markings I see on it are these two (see attached pics). Can you tell if it is a "1" or "0" from these pics? I just want to be sure! Thanks for any help!

[Stoats]

You know why Americans fret about Enfield boltheads and Brits don't?

Cos the SAAMI specs are in fact wrong...

Not a lot of people know that...

The correct no-go gauge is .074.

Here's a quote from a proper expert:


SAAMI .303 "no go" is .067". The correct design headspace gauge to use is the Commonwealth "Field" of .074" (war use tolerance allowed up to 0.84"). Not surprising that some perfectly in-spec rifles "fail" a SAAMI gauge, as the correct minimum "go" is 0.64".

Thus SAAMI spec was wrong from the outset, and now some US manufacturers make cases with thin rims that would not pass a standard military quality check if that ammo were being procured today.

In Europe and most of the world, shoooters are best to ignore SAAMI and stick with the real headspace specs, as all surplus and most modern and recent production (HXP, PMP, Privi, Wolf, S&B, PPU, Kynoch, etc) use the normal military dimensions.

In US you have the silly situation that two specs of ammo are in circulation, but the majority of shooters don't understand the situation. This has spawned a vast internet headspace confusion, and a scramble for longer boltheads to "tighten up" headspace. The ironic thing is that most of these "headspace tighten-ers" are probably actually (a) making an in-spec rifle out of spec (most have no idea about fitting a bolthead correctly); (b) actually accelerating wear on their rifle by then having over-tight headspace when they come to use military-spec ammunition.

The other factor in this is that over-generous head space has no real effect other than possibly to shorten the life of poor quality (thin) brass. Ergo, its best to stick with the specification that was designed into the weapons system.

[fatelvis]

Wow! Thank you! That is a new one to me. I currently load S&B brass for my one and only rifle, so I guess as long as I only neck size, I'm good to go!?

[Gtek]

As a general rule .010" is the range. Now if you are on the big end on headspace and have thin rimmed cases you might be going out. Depending on how you are proccessing your brass and given headspace will also factor into case life. Bolt heads are cheap and if you can snug her up I would-IMHO. Gtek

[Stoats]

As an amateur you are unlikely to ever correctly fit a replacement bolt head.

If the bolt face ends up not entirely square, bad things happen.

I would just leave well alone unless fresh cases are splitting & neck-size or full-length size as you desire.

NB: this Enfield bolt-head obsession is a purely American phenomenon, for the reasons given above. Now, correct bedding, on the other hand.........

[blaser.306]

I have also read that running 30/40 crag brass thru the .303 br fl die and fireforming will make a fairly large difference to a "sloppy" headspaced chamber! The crag has a thicker rim and tightens things up!

[fatelvis]

Thanks for the tips guys! As far as the bedding, I heard that a business card under the barrel at the tip of the stock helps accuracy. Is that what you meant?

[nicholst55]

I have also read that running 30/40 crag brass thru the .303 br fl die and fireforming will make a fairly large difference to a "sloppy" headspaced chamber! The crag has a thicker rim and tightens things up!

Actually, that is incorrect. The .30-40 Krag has the exact same headspace specs - under SAAMI - as the .303. What you do get is a longer case neck. The big problem with headspace is the fact that SAAMI decided to use the Krag headspace specs for the .303. American brass is made to this too-small spec, which creates the problem.

[Stoats]

Thanks for the tips guys! As far as the bedding, I heard that a business card under the barrel at the tip of the stock helps accuracy. Is that what you meant?


In principle there should be 2-6lb downforce from the barrel on the muzzle bearing, and the barrel should self centre when displaced. A shim there can help. I had one that I thought would need shimming, which I did with a bit of card. It shot badly. Took the card out and it shot great.

With Enfields assume nothing unless something is clearly very wrong, like sloppy stock fit. shoot first and see.

[MtGun44]

Headspace, for a reasonably bright handloader, is WAY overratted as an issue. Fit your ammo to
your gun and go on. Getting the headspace perfect is something to ensure ammo interchangability
and safety in a wide range of individual firearms. If you are custom fitting your ammo to your
chamber it approaches irrelevance what the headspace is - as long as the brass will survive the
first firing in good shape and the dies can avoid overworking the brass, yet make it chamber OK.

Bill

[I'll Make Mine]

Headspace isn't something the handloader can fit, if it's a rimmed cartridge like .303 or 7.62x54R; you'd have to add to the rim thickness of the cartridge to correct excess headspace, and then you wouldn't be addressing the mechanical issue that causes the headspace to be out of spec -- such as, potentially, damage from an overload or excessive wear in the lockup mechanism.

[Multigunner]

Commercial Krag cases at one time had a thicker rim than you'll find on modern Winchester or Remington manufacture Krag cases.
I have an old .30-40 cartridge in my collection that has a .063 rim thickness.
The main reason reloaders were using Krag cases in their .303 was the Boxer primer of the Krag vs the Berdan primer of the .303 British, and the fact that most WW1 era .303 British cases manufactured in the U S had brittle case necks and other issues that made sucessful reloading problematic.
Krag cases salvaged from old stores of surplus ammunition broken up for components were also dirt cheap for many years.

The Krag rim has practically the same specs as the .303 rim. Pre WW1 .303 cases often had rims no thicker than .056 with a max of .064. The milspec .303 cases I've miked run from .060 to .063.
Nominal rim thickness of the milspec Krag case was .060 with the max as .065.

The Krag case has a much longer neck, but the shoulder is further back, so no .303 resizing die is necessary for fire forming a Krag case to a .303 British chamber. just trim the neck to the .303 OAL load and fireform.


British factory headspace specs for the SMLE rifle were minimum .064 and Maximum .067. Thats for a new rifle after proof testing.
The .074 Maximum is for a worn rifle. If headspace exceeded .074 the rifle would have either a new bolthead or a new bolt body or both fitted.

Seller & Bellot is well recognized as the worst .303 case for reloading. Not just my opinion, many have had problems with the S&B cases.

Both my SMLE and No.4 rifles have headspace under .068, and these handle Remington cases with great results, thirty or more reloads per case. I've never discarded a case due to case body cracking since rectifying headspace. Only neck splits have been due to deep scratches from a defective magazine feed lip.

PS
The reason British shooters don't fret about headspace is that traditionally very few British .303 rifle shooters reload.
The British NRA UK does not allow handloads to be used in sanctioned matches that the Lee Enfields participate in.
Due to the drying up of the mildly loaded British 7.62 NATO ammunition once supplied for match shooting at Bisley all No.4 rifles converted to .308 must be reproofed for the higher pressures of modern 7.62 and .308 long range matchgrade ammunition.
The British NRA always distributed surplus .303 ammunition supplied by the Ministry of Defense (or War Office) to civilian target shooters. Only a very few British target shooters experimented with hand loaded ammunition.

[Stoats]

PS
1. The reason British shooters don't fret about headspace is that traditionally very few British .303 rifle shooters reload.
2. The British NRA UK does not allow handloads to be used in sanctioned matches that the Lee Enfields participate in.
3. Due to the drying up of the mildly loaded British 7.62 NATO ammunition once supplied for match shooting at Bisley all No.4 rifles converted to .308 must be reproofed for the higher pressures of modern 7.62 and .308 long range matchgrade ammunition.
4. The British NRA always distributed surplus .303 ammunition supplied by the Ministry of Defense (or War Office) to civilian target shooters. Only a very few British target shooters experimented with hand loaded ammunition.

1. Nah, most reload and have done for many years once the HXP started drying up and the PRVI got really expensive.
2. Not true at all.
3. Not quite true - the NRA got paranoid about the (relatively new) 155gn RG loads at Target Rifle competitions, so recommended people get a reproof (there's no legal means by which they could force it). I've not heard of a rifle failing reproof though. Many had to get their throats reamed out a touch though, though this was independent of rifle type.
4. Not for many, many years has there been issued .303 ammo at NRA comps, and only then was there issued ammo at the Imperial Meeting in July, which have been essentially 7.62 only since at least the 70s. In principle you could shoot 5.56mm or .303, but I have only ever once seen either of these for issue. Never saw anyone shooting .303 or 5.56mm at these comps either cos frankly you'd be mad to - remember we're talking Palma-type rifles here.

[Multigunner]

1. Nah, most reload and have done for many years once the HXP started drying up and the PRVI got really expensive.
2. Not true at all.
3. Not quite true - the NRA got paranoid about the (relatively new) 155gn RG loads at Target Rifle competitions, so recommended people get a reproof (there's no legal means by which they could force it). I've not heard of a rifle failing reproof though. Many had to get their throats reamed out a touch though, though this was independent of rifle type.
4. Not for many, many years has there been issued .303 ammo at NRA comps, and only then was there issued ammo at the Imperial Meeting in July, which have been essentially 7.62 only since at least the 70s. In principle you could shoot 5.56mm or .303, but I have only ever once seen either of these for issue. Never saw anyone shooting .303 or 5.56mm at these comps either cos frankly you'd be mad to - remember we're talking Palma-type rifles here.

Rifles with No.4 type actions not originally manufactured and proofed as .308 rifles, including the L42 sniper rifles, are limited to ammunition that generates a mean average working pressure of no more than 3650 BAR (aproximately 53,000 PSI) unless reproofed to modern CIP standards.
Rifles reproofed at 5190 BAR are authorized for use with ammunition with a MAWP of 4150 BAR.
As for legality the NRA does not have an obligation to allow use of their ranges by anyone who ignores safety warnings and refuses to have their rifle inspected and reproofed.

The surplus .303 ammo was distributed to NRA members the same way that Radway Green ammo was distributed, till supplies of suitable ammunition ran out. Shooters bought the ammo from the NRA.
Even POF .303 was used in this way despite the incidence of misfires and hangfires of this old ammunition.

I can remember a flap in the 80's when a british police marksman unit were caught using .308 handloads in a competition. At the time there were a number of articles on how rare it was for British shooters to use handloaded ammunition. Authoritative texts from the WW1 era and later agree that reloading of .303 ammunition was very rare.
Parker Hale service rifle catalogs and other sources advertised the availability to civilian marksmen of second quality .303 government ball ammunition turned down on inspection due to minor cosmetic issues.
The commercial .308 Chamber of the Enforcer and similar purpose built .308 rifles, and even tighter chambering of many converted No.4 rifles makes for no significant reloading problems due to headspace.

I've seen nothing that indicates that British shooters were ever as interested in reloading as American shooters have been. That includes reading available PDF downloads of British ammunition and propellent manufacturers publications and such works as "the Book of the Rifle" by T F Freemantle (Lord Cottesloe).

If Headspace (and resulting head gap) of a Lee Enfield rifle is much over the British government approved factory specification of .067 or less then sucessful reloading requires use of milspec cartridge cases with the thicker sidewalls near the base, or specialized fire forming methods such as use of a circle of fishing line or a thin O-ring to use as a spacer when a case is used for its first firing.

Commercial sporting ammunition is intended for use in sporting rifles built to sporting rifle specifications. Suchammunition is not "undersized" its within original factory specifications for the .303 cartridge.
I've been told that some high quality British double rifles will not close on most milspec .303 ammunition, due to the looser tolerances of wartime manufacture ammunition.
A rim thickness a few thousandths under the maximum specification will cause no feeding problems, but a case with rim thickness over the maximum can make a rifle useless. Same goes for other dimensions, especially in tropical regions where moisture contributes to fouling and some rust in a chamber is always a possibility.

When the Ross rifles had difficulty with feeding and extracting it was not because the chambers were "undersized", the chambers met the original specification for the milspec .303 cartridge. The Ross chambers, along with many SMLE and other military .303 rifles were reamed out with an "enlarging reamer" because British supplied .303 ammunition often exceeded the maximum dimensions as set down in the original cartridge drawings.

For a modern manufacturer of sporting ammunition to use the loosened wartime expediant tolerances rather than the original specifications would not make sense at all.
Hundreds of millions of rounds of .303 ammunition were dumped in the north sea after each world war, because the ammunition was not within reasonable tolerances and there was no longer the pressure of wartime necessity in keeping the ammunition on hand for emergencies.
Most quality British manufactured Milspec .303 ammunition has long pasted its shelflife date and is not reliable for use in any serious application. Some Canadian Milspec .303 manufactured in the 1970s and kept in optimal storage conditions is still within the tolerances of regular lot testing for military use. Same can be said for some other manufacturers ammunition. Other manufacturers like POF have a very spotty record.
I'd not bother with the Lee Enfields at all if I had not found ways to handload for them despite the generous chambers and sometimes generous headspace.

Headspace, and resulting headgap is of importance to the handloader, less so to those who use only factory ammunition, and even less important to those who use only milspec factory ammunition and don't intend to reload.

The generous chamber of the British .303 rifles was never intended for ease of reloading. If within original factory specs reloading is not a big problem, but if worn to very near the point where an armorer would be obliged to rectify headspace or deliberately wallowed out with an enlarging reamer, then special precautions (such as fire forming and neck sizing only) are in order if you wish to handload with anything approaching a decent case life (two dozen or more reloadings per case).
If satisfied with at most two or three reloads before even milspec cases may fail due the cracking at annular rings formed on first firing, then so be it, thats a personal choice.
Seller & Bellot cases are if anything more likely than Remington commercial cases to form annular rings on first firing, despite a very slightly thicker rim.

PS
If anyone is wondering why many converted No.4 rifles had undersized bores, its because British and most European 7.62 NATO ammunition used bullets of .3075 or less diameter.
Target barrels were developed with bores as small as .306 to provide the best seal with these undersized 7.62 milspec bullets.
In target matches everyone had to use the same type of ammunition, at the time that was Radway Green 144 gr bullet at 48,000 CUP/50,000 PSI no handloads or speciality commercial ammunition was allowed.
Use of the Radway Green 155 grain loads with larger bullet diameter caused concerns over higher pressures.
Radway Green and the Birmingham Proof house ran tests that confirmed higher pressures, and that some tight bore/tight chamber rifles when used with modern long range match cartridges caused chamber pressure increases that exceeded CIP limitations for the .308 cartridge.

[Stoats]

I guess I must have imagined shooting every Imperial meeting from 1994-2003, and a slack handful of Phoenix and Trafalgar meets, as well as innumerable club comps at Bisley in the same period...

[Stoats]

FYI, the RG Mk.VII basically ran out by about 1995, the HXP was intermittent and basically gone by about 2001 or so. Then there was some excellent Yugoslavian Mk.8z greased up in 250rd cardbord boxes that was absolutely superb but corrosive like you wouldn't believe that was around from about 2000-2002. Then there was commercial FNM and PRVI, and for the rich Carmichael made up some "match" .303 that was about 50p a bang.

Rifle handloading in the UK is a much more recent phenomenon than in the US, to be sure - really only took off in the late 90s or so once factory got expensive.

Btw, for the 155gn 7.62, at the Imperial they gauged the freebore of every rifle & put a sticker on the barrel to indicate they had done so...

[HollowPoint]

In answer to your original question about what number your bolt head is; I think it's a number One. I've never seen an original bolt head with two different numbers stamped on top of it.

Either way, it doesn't really matter. If you're wanting to reduce your Head-Space by changing out your bolt head to a slightly longer one, you're better off measuring the length of your present Bolt Head and trying to find one that measures a little closer to what you'd like it to measure.

The number that's stamped on them really doesn't give you a consistent measurement. Before re-barreling my No. 4 I went through the same ordeal of trying to find what I thought would be the ideal Bolt Head that I could use to reduce my Head-Space based on the numbers stamped on them.

Right now I have in my possession a Number 4 Bolt head that's shorter than the number 1 bolt head that I used when I installed my new barrel. Trusting solely on the number that's stamped on it is a hit or miss affair. (mostly Missing) It's better to trust your calipers instead.

That's what I did. I found a gal that was selling factory Enfield Bolt Heads on Ebay. Each bolt head she listed for sale also listed the measured length of said Bolt Head. From the measurement I'd gotten off of my existing Bolt Head and the measurements listed on the various Bolt Heads that this gal was selling, I was able to determine which would work out best for my needs.

I found what I was looking for but, in the end I never used it because when I re-barreled I went with a No. 1 Bolt Head that I already had.

HollowPoint

[m.chalmers]

Looks like a 0. Using a larger bolt head will help the brass last long, as long a it's in standard. Mic any bolt head as the size 0,1,2,3 are in a range. Some #0's are bigger then some #1's and the like.

Good info here:
http://www.milsurps.com/content.php?r=296-Headspace-101-for-.303-s

[Multigunner]

I guess I must have imagined shooting every Imperial meeting from 1994-2003, and a slack handful of Phoenix and Trafalgar meets, as well as innumerable club comps at Bisley in the same period...
The NRA UK warnings posted at Bisley and in the NRA journals on the subject of converted No.4 rifles were after 2003. The most recent and detailed warning was in the Spring 2010 edition of the NRA journal.
The Radway Green 155 grain ammunition was of some concern earlier on, but has little to do with the more recent warnings which involve contracted RUAG long range match ammunition and similar maximum pressure .308 and 7.62 Long Range ammunition and Long Range Special Ball.




FYI, the RG Mk.VII basically ran out by about 1995, the HXP was intermittent and basically gone by about 2001 or so. Then there was some excellent Yugoslavian Mk.8z greased up in 250rd cardbord boxes that was absolutely superb but corrosive like you wouldn't believe that was around from about 2000-2002. Then there was commercial FNM and PRVI, and for the rich Carmichael made up some "match" .303 that was about 50p a bang.

Rifle handloading in the UK is a much more recent phenomenon than in the US, to be sure - really only took off in the late 90s or so once factory got expensive.

Btw, for the 155gn 7.62, at the Imperial they gauged the freebore of every rifle & put a sticker on the barrel to indicate they had done so...

You can read the NRA warnings and results of testing by Radway Green and the Birmingham Proof authority. The NRA journals are available free online and the complete report by the Birmingham Proof house is also available online.

The upshot is that 7.62 chambered No.4 rifles are not chambered to the lose tolerances of most of the SMLE and No.4 rifles chambered in .303. The 7.62 rifles were not wallowed out by use of enlarging reamers, and headspace specifications are usually within CIP or SAAMI limits.

BTW
The Maximum SAAMI headspace specs for the .303 are .071.
This is only .003 below the British milspec of .074 before the rifle must be repaired, and .004 greater than the .067 factory specification for the SMLE.

[Stoats]

I had a custom proof done at the Birmingham proofhouse.

Amateurs. Butchers.

But that's for another time...

[curator]

All of my 7.62 NATO Lee Enfield rifles, Long Branch DCRA, L39A1, A.J. Parker "Excel", and PH 4T rifles are very tightly headspaced. I have fired commercial 7.62 NATO cartridges thought them but prefer my hand-loads with lower pressures. Case life is very good with 15-20 loadings expected. Sierra 168 HPBT Match-Kings at 2400 fps seems to be the magic load. I like Reloder 15 or IMR4895 to get there.

[dualsport]

I've been planning to get .303 gauges but am now wondering if the expense is justified. I have quite a few .303s and all have decent case life. I've even fired factory loads in a couple 'DP' marked rifles without any issues. Both (to my surprise) arrived all matching even the wood and appeared hardly fired at all, just cut strikers. With no clue why they were 'DP'd I thought maybe headspace was it but can't tell by looking, of course.

[fatelvis]

Res45 ran this past me, truly a good idea! Thanks RE!
http://www.milsurps.com/showthread.php?t=24699&page=4