LE No4 bolt head timing to bolt

[I Dont Care About You]

Keep in mind that if your rifle "barely swallows" your NOGO gauge, you are only .003" over minimum, and no where near maximum. And all the commotion about head space in a No. 4 Lee Enfield, using those gauges, is only about clearance for the case rim - nothing, really, to do with the fit of the cartridge body to your rifle's chamber.

The No Go is the maximum, that's the entire point of the No Go dimension. Field is a determination of safety.

Headspace in a LE has a relation to the stretch of the case body upon firing. For those of us reloading for our LE rifle, correct headspace will help to minimize body stretch and potential case head separation.

I have exchanged bolt bodies in Lee Enfield rifles, but as per the various articles by Peter Laidler on milsurps.com, I do not think that is a minor thing to do - is some stoning or at least checking that is required. I think the bolt and receiver were originally made / fitted to stay together - then the bolt heads were the parts that had a process / standards to swap out.

I wouldn't take a stone to my bolt but the lugs can easily be lapped to correct uneven bearing surface between the lugs. However that can increase headspace.

 

[bearhunter]

There is a way to ensure nearly "zero" end play in 303 British - was described some time ago on CGN - run new unfired brass into a die with a larger diameter neck - like 8mm or .338 - then into a 303 British FL size die to bring that neck down to size - but adjusting that sizing die to just so allow that "false shoulder" to create the "head space" - then you know the case head (rim) is tight to bolt head face when you first fire that round - after that, be careful not to push that shoulder back any more than you need to for easy chambering. The amount of end-play - "headspace" - is under your control by how much you push back that fired shoulder. If you want to do similar with store bought ammo, can use the O-ring trick to get about same thing.

Thanx for the details, I just assumed the OP knew how to do this. Others of course may not, so your post is spot on.

 

[slug]

A while back, I bought a No. 4 sportier for cheap. The ask price was $75, and I told him $100.
If it were totally pooched, the magazine and Singer sight were worth it.
I hadn't realized that the bolt head was very tight on closing and the bolt handle wasn't closing fully.
For $100, I wasn't looking too closely.
So, I put the bolt head in a padded vice, and with fine grinding compound on the mating surfaces and upper threads, rotated the bolt handle back and forth.
After about 40 or 50 cycles, the rotation was much smoother, and the bolt operated properly.
Headspace wise, the bolt closed with slight force on the No-Go gauge which was acceptable, but not great.
I found a new bolt head, and all looks good.

 

[Potashminer]

The No Go is the maximum, that's the entire point of the No Go dimension. Field is a determination of safety.

Headspace in a LE has a relation to the stretch of the case body upon firing. For those of us reloading for our LE rifle, correct headspace will help to minimize body stretch and potential case head separation.

I wouldn't take a stone to my bolt but the lugs can easily be lapped to correct uneven bearing surface between the lugs. However that can increase headspace.

I could not find where SAAMI defines what is a NOGO gauge - go here to read what Forster says about it: https://www.forsterproducts.com/product-category/gunsmithing/headspace-gages/ If you follow this link, you will see "Read More ..." to click near top of page - then scroll down a few screens to this:

"Ordering Information

Forster offers three lengths of headspace gages for most rifle calibers, in order from shortest to longest:

GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gage, the chamber will accept ammunition that is made to SAAMI maximum specifications. The GO gage is essential for checking a newly-reamed chamber in order to ensure a tight, accurate, and safe chamber that will accept SAAMI maximum ammo.

NO-GO: Corresponds to the maximum headspace we recommend for gunsmiths’ chambering new bolt-action rifles. This is not a SAAMI-maximum measurement. If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications, or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. The NO-GO gage is a valuable tool for gunsmiths’ reaming new chambers, in order to ensure tight and accurate headspace. (Bold added by me)

FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI-specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin."

Even if you get your rifle chamber to gauge to perfect SAAMI minimum for 303 British - .064" - and then use commercial ammo that is made within SAAMI tolerances, you can still end up with a commercial rim that is up to .010" shorter than GO - in other words, about "triple" the "headspace" (end play) that you have now? I think what you have described is a chamber that is at the long end of tolerance for a newly installed / newly chambered barrel - as per FORSTER - I could not find where SAAMI says anything about that. I have no clue what standards were used by the makers of the No. 4 Mark 2 rifle - I think they were made in Great Britain, where I doubt that SAAMI applies.

 

[Hitzy]

Neck sizing pretty much solves this headspace issue.

 

[I Dont Care About You]

So, I put the bolt head in a padded vice, and with find grinding compound on the mating surfaces and upper threads, rotated the bolt handle back and forth.
After about 40 or 50 cycles, the rotation was much smoother, and the bolt operated properly.
Headspace wise, the bolt closed with slight force on the No-Go gauge which was acceptable, but not great.
I found a new bolt head, and all looks good.

I would surmise that the lapping of the bolt head to the body shortened the OAL of the bolt assy and resulted in slightly long headspace. Slightly long headspace is where I am at this time.

 

[I Dont Care About You]

Neck sizing pretty much solves this headspace issue.

It's a crutch to circumvent the actual problem, which is excess headspace. The proper solution is to correct the headspace.

 

[I Dont Care About You]

Even if you get your rifle chamber to gauge to perfect SAAMI minimum for 303 British - .064" - and then use commercial ammo that is made within SAAMI tolerances, you can still end up with a commercial rim that is up to .010" shorter than GO - in other words, about "triple" the "headspace" (end play) that you have now? I think what you have described is a chamber that is at the long end of tolerance for a newly installed / newly chambered barrel - as per FORSTER.

This is what I think too. I'm not doing major surgery to correct this, but if I can swap out some combination of bolt and bolt head to minimize the headspace dimension, then that would seem to be a viable solution. A couple of hundred dollars to correct this issue would seem to be reasonable investment.

 

[bearhunter]

It's a crutch to circumvent the actual problem, which is excess headspace. The proper solution is to correct the headspace.

No, it isn't a crutch. It's a very viable and simple solution for a problem that really doesn't exist under the parameters the firearm was built under. If your existing bolt head is clocking up as designed, then leave it alone and work within it's capabilities.

Tightening up the headspace can easily lead to other issues, depending on the cases you intend to use.

Fireforming your cases, for a particular rifle is a long established Bench Rest tradition.

Why are you trying to fix something that isn't broken????

 

[cosmic]

It's a crutch to circumvent the actual problem, which is excess headspace. The proper solution is to correct the headspace.

Dude - A Lee Enfield with zero rim headspace will still have its brass balloon into its oversize chamber, with the resultant stretching issues. Neck sizing eliminates brass stretch! Additionally, neck sizing reduces neck runout. Guess what that does?

 

[purple]

Neck sizing extends case life and tends to produce more accuracy. It's a good way to go with a LE which headspaces on the rim and allows the brass to expand to the far horizons in a chamber of unknown dimensions. It's a well proven practice when reloading for the .303, even when the rifle qualifies on headspace gauges.

 

[I Dont Care About You]

No, it isn't a crutch. It's a very viable and simple solution for a problem that really doesn't exist under the parameters the firearm was built under. If your existing bolt head is clocking up as designed, then leave it alone and work within it's capabilities.

Tightening up the headspace can easily lead to other issues, depending on the cases you intend to use.

Fireforming your cases, for a particular rifle is a long established Bench Rest tradition.

Why are you trying to fix something that isn't broken????

Because it isn't correct and it can be fixed relatively easily. Why wouldn't I fix that?

Dude - A Lee Enfield with zero rim headspace will still have its brass balloon into its oversize chamber, with the resultant stretching issues. Neck sizing eliminates brass stretch! Additionally, neck sizing reduces neck runout. Guess what that does?

Who said I'm not doing the neck sizing?

 

[tiriaq]

You have a No Go that is .067. Go is .064. Set your micrometer to .003 and hold it up to the light. That is what you are dealing with.
The rifle is well within military spec for use with service ball, and .003 is irrelevant if you handload.

By all means, if you have access to assorted boltheads, try swapping them and see if you can get something under .067 - but it isn't going to make any practical difference.

 

[I Dont Care About You]

You have a No Go that is .067. Go is .064. Set your micrometer to .003 and hold it up to the light. That is what you are dealing with.
The rifle is well within military spec for use with service ball, and .003 is irrelevant if you handload.

By all means, if you have access to assorted boltheads, try swapping them and see if you can get something under .067 - but it isn't going to make any practical difference.

I am well familiar with how small 0.003" is. I have chambered numerous barrels.

Having the correct headspace is not irrelevant and I understand the practical application of sizing dies with respect to the case shoulder. IF 303 headspace is irrelevant, why do guys suggest the O-ring method?

I started another thread on headspacing 303 to the shoulder and everyone wanted to talk about 303 headspacing to the case rim. Here I began a thread about 303 headspacing to the rim and everyone wants to talk about headspacing to the shoulder. WTF?

I found a guy with an assortement of NOS bolts for $40 a piece and bolt heads can be had for $30 each. I can try various combinations to find one that headspaces correctly and then sell off the rest ... probably at a profit, thus making the entire enterprise free to extremely cheap. Why on earth wouldn't I do that?

I have experience lapping bolt lugs and the lapping compound on hand. It's simple and quick and ensures that a replacement bolt will fit my rifle correctly.

Everyone seems almost offended that I wouldn't simply accept a rifle that is out of spec? I don't get it.

 

[tiriaq]

Out of whose spec? SAAMI's?

At those prices, I should be selling bolt heads. Have a decent selection of unaltered 2s and 3s, including LB ones.

 

[I Dont Care About You]

Out of whose spec? SAAMI's?

At those prices, I should be selling bolt heads. Have a decent selection of unaltered 2s and 3s, including LB ones.

Outside the headspace gauge spec. And if we are going to argue that the headspace gauge is not relevant, then why on earth do we have them? Those gauges exist for a reason.

I might hit you up for a #2 bolt head if I can't find something that works. The one I have doesn't time properly with the original bolt.

 

[woodchopper]

well there a more then the headspace issue at play

Headspace based on military spec is NO GO of .074"

The next issue is with generous / oversized chambers. You could have a minimum headspace but end up blowing cases all out of shape because the chamber was cut oversize to accommodate war time production and mud.

 

[purple]

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.

 

[I Dont Care About You]

well there a more then the headspace issue at play

Headspace based on military spec is NO GO of .074"

The next issue is with generous / oversized chambers. You could have a minimum headspace but end up blowing cases all out of shape because the chamber was cut oversize to accommodate war time production and mud.

True, however .....

A. I can't easily and cheaply correct a chamber size problem.
B. My rifle is a 1954 built Mk2 and so that is unlikely to be the case.

 

[cosmic]

Well - The o-ring trick is only employed on the first firing, in an attempt to minimize case stretch at the web. No need after that. Whether this has any quantifiable benefit, is hard to determine.
Over the years, I have collected a number of bolt heads ranging from 0 to 4 (yes 4!). A fella cannot rely on the bolt head number to ascertain the critical length dimension. Armed with a proper measured candidate bolt head, if it didnt clock sufficiently, I would have no issue stoning the end face of the bolt body. That would allow one to keep the original matching bolt, which was likely fitted for proper lug engagement.