Enfield in .223

[RJW NZ]

RJW in NZ:

I have been watching buttons going through blanks a bit lately.

The initial run of 20 P-14 barrels is just about finished to profiled and threaded state and then we move on to SMLE and No5 barrels. No4 barrels are bit further away because of the issues of indexing and absolute headspace reference.

It is all happening on a very malnourished shoestring, but it is happening.

The biggest problem is not with the barrels but with the condition of the original bolts and receivers. Too much wear on the locking shoulders in the body and the effort of rebarreling is fairly pointless, regardless of how many No3 bolt heads you own.

However, if you have a "bitza" No5, a 7.62 x 39 rework will be a hoot. That style is where the M-10s started. Mini-30 mags work fine if you can get them. Alternately, if you have a stash of AK types, these can be used but with the reinforcing plates carefully ground off the top sides of the mag body. The controlling feature is the width of the existing mag well. I have never been keen on thinning the receiver side walls in rear locking actions. Previous notes about mag spring tension apply. Your biggest problem will be modifying the bolt head to run with the dinky rimless cartridge.

Hi Bruce in Oz, How about this? Why don't we see how much interest there might be for a run of H barrels, and I set up a posting on Enfield Resource.com and have people email me with expression of interests if H barrels were to be made.
Last year I set this up for James Sweets 1954 book and had over 100 replies to that before those names went across to his family to take what next steps they might.
Over to you, rjwnz

[Peter Laidler]

Any other technical views on the what I consider to be redundant collared bolthead for a 5.56mm conversion. It does seem to over complicate a very simple conversion

The actual mechanics of getting a No4 to shoot a 5.56 is simple - if you don't complicate it. But all that palaver with a bolt head seems a bit......., well, as I said, complicated to me

Just forgot to say but had a PM from non forumer that the collar was to ensure that the base of the cartridge/centre of the primer remained central to the striker in the bolthead. But it will remain central in any case UNLESS the chamber/bore is eccentric. And an eccentric bore doesn't need a collared bolthead...... it just needs a half decent fitter/turner!

Nope, I still can't see it

[Son]

Is the case supposed to be pushed across the bolt face (during extraction) to the left sidewall so it can be ejected by friction?

I thought the idea of the collared bolt face was to locate the case against an ejector post/spring during extraction/ ejection. Will the smaller diameter of the 5.56 stay on a full size boltface?

[newcastle]

It would seem that if the case is pushed to the left by the extractor then the ejection would be forced by the case hitting the ejector screw. How would headspace be set? Does a non rimmed cartridge make a difference? Peter seems to imply that if the feeding can be sorted out (this is a trial and error thing) then just having a new barrel which is chambered and fitted correctly, and with a different extractor fitted to a standard bolt head, this could be a relatively simple build.

[Bruce_in_Oz]

Regarding the extractor / bolt-head thing:

Note that when the time came to build No4s in 7.62 NATO, (L-42 etc) that the engineers designed a new extractor. This has a wider and deeper claw and a slightly different shape to its arm. That is because it had to retain a smaller rim so that it was dragging at the right pressure along the LHS receiver wall until it got booted out.

The trick with 5.56 is that the case is much smaller in diameter than the original .303. Thus, you need an entirely new extractor. The problem with this dinky case is that the amount of "swing" of the extractor that is needed to push the case sideways to achieve the correct pressure on the receiver is much larger than for the .303 or 7.62. The problem becomes one of building an extractor that can produce this swing and still be able to slide up the extractor cut in the barrel without losing its grip on the case. I think you will find that you will need an extractor claw with quite a long "nose" to achieve the desired result. Not only that, but the "rim" on a 5.56 case is MUCH thinner and shallower than on a 7.62 case, thus things get much more critical.

I was once the proud owner of a Lithgow Hornet built on a SMLE action. Now there is a dinky case. Feed was variable but extraction was good. The bolthead had a slot on the LHS and a spring-loaded ejector let into the LHS wall of the receiver. Extractor was a narrow little thing but it worked. Pity about the poor feeding on such an accurate little rifle.

Those folk who have noticed they are getting very eccentric striker marks on their primers, may want to check out the looseness of fit of their bolts / boltheads. The bolthead is supposed to be supported in the small ring in the receiver, immediately at the top of the feed ramp. The pressure of the extractor on the case tends to push the bolthead to the left. If the support ring is oversized and/or the bolt head is excessively worn / undersized, this leftward movement can be surprisingly large; hence off-centre striker marks. Receivers that are worn in the "support area imediately behind the locking recesses will "float even more. Note also that when the action is cocked, the bolt tends to tilt down at the front, albeit slightly. When the action is fired, for a brief instant the bolt body is "free". All these instances of "racing fit" can contribute to eccentric striker marks and that other interesting phenomenon; bolt handle "flip". On this latter phenomenon, I have noticed that if the bolt handle is JUST clear of the exterior of the butt socket when the action is fired, the angle of the "flip is usually less. ry-firing with no dummy cartridge in place tends to produce greater "flip" than live firing. Some individuals have relieved the under-surface of their bolt handles or attached small rubber pads to that surface to alleviate the problem; all with varying degrees of success.

All of my toys are very "pre-loved", so, could any lucky owners of "mint" rifles care to let us know what sort of striker eccentricity and/ or bolt handle "flip" they have noticed?

[tbonesmith]

Some individuals have relieved the under-surface of their bolt handles

I've noticed this on some old clapped out SMLE range rifles and wondered WHY... Cheers.

All of my toys are very "pre-loved", so, could any lucky owners of "mint" rifles care to let us know what sort of striker eccentricity and/ or bolt handle "flip" they have noticed?

Variable striker eccentricity but relatively central, similar bolt handle "flip" to plenty used ones.

[Peter Laidler]

As I said earlier, my 5.56mm No4 project only got as far as firing and extracting with a 7.62mm extractor. It extracted well enough in spite of the thicker rim of the 7.62mm over the 5.56 rim but didn't proceed to to ejecting. While on the subject of rim thickness, the extractor certainly clawed the 5.56mm rim during the primary extraction phase. ON that basis, the primary extraction operated perfectly too.

However, I did get a 9mm to extract and eject (except the the last round wouldn't eject successfully) using the left body side friction to cause ejection. What I did was modify the underside of the 7.62mm extractor so that the claw moved over the bolt face to the left more so that the repositioned tip of the claw would physically push the smaller 9mm case (but same base rim diameter as the 5.56mm case) further over to the left hand body side wall to effect ejection. This worked well and in theory SHOULD work for a 5.56mm case. I didn't do anything about the extractor spring tension.

I don't think that eccentricity of striker played any part in my feeble efforts and certainly didn't suffer with any misfires as a result of it.

Just from the 'keep it simple' engineering point of view, while there might be a case for recessed bolt heads in some instances, there isn't a need in a No4/5.56 conversion. But that's only my opinion and as I say, I'm an Armourer principally and an engineer secondly but not a gun maker or gunsmith (how I hate that cover-everything term.....)

[Son]

In a particular .22 trainer of mine, the extractor claw was pulling the bolthead so far to the right that the striker (offset positioned 180deg opposite the extractor) was pulled far enough to hit well inside the rim of the cartridge, failing to fire. I measured the movement at the time to be just under a mm- pretty huge on the base of a .22LR case!

Here's a pic of the ejector in the Lithgow Hornet. It is a simple rocking pivot with a leaf spring acting on the outside to hold it in. The bolthead has an angled slot in it to allow the ejector to get into the case as the bolt is drawn back.
They feed very reliably, they extract very reliably. (as long as the feed lips and magazine catch are set right) Other than that, the only time anyone has problems, it will be the last round of five coming out of the magazine... load four and the last one gives no trouble at all... go figure....


Attachment 26001

[trooper554877]

theres a LMG and now a GPMG in the inventory that uses an ejection system similar to the hornet.
seems to work quite well
cheers
NED

[Dr. Strangelove]

Sorry to bring this back from the dead but did anyone make much progress on a .223 Lee Enfield?

Peter - did you take your work any further?