New Manufacture No4 Barrels

[Res]

What would be the best way to get one of these barrels in New Zealand?

[Peter Laidler]

Simply apply for an import permit and make a private import. Simple as that! Think that it's going to be difficult....... Think again. My friend in ChCh did it with a siongle shot SA80

[Res]

Done that plenty of times for ar parts.
Have had a couple of pm with tbonesmith so well under way

[MJ1]

I would like to thank all the posters for this very informative thread. I look forward to future postings. For several years I had thought I was very lucky to have two like new barrels in 303 and 7.62 and two serviceable receivers to mate but this has let a great deal of sunshine on the larger picture of our sport/ passion.

I have been away to middle earth for a good long time with no shooting at all but now reading this post I feel the juices starting to warm and flow again. Thank you all.

Note to self, contact Brain.

[Surpmil]

Bruce in Oz makes an excellent point about worn bodies. I know the telltale signs of one thats too far gone to mess with but sure wish I could lay my hands on a calibrated test bolt. I just know I'm going to get worn out Century Arms and other "imports" from God knows where belonging to people who are looking for a new rifle with a new barrel! The real world will strike!!

A test bolt to gauge what? The wear on the recoil lugs or the alignment of the boltway to the barrel threads/shoulder, or the diameter of the bolt way?

[Brian Dick]

Since I've never used one, I'd let Peter or someone else with experience answer just exactly what the test bolt does and how it works. Most receivers I've seen that are known ZF have worn bolt ways which usually means the sear is dragging or even catching on the LH locking lug. It's a given that the hardening in the sear lug recesses is most likely very tired when the weapon has seen such extensive use. I've seen two No.4T rifles that were both marked ZF because of worn bolt ways. The interesting part is that both rifles had been through complete FTR in the mid 1950's then must have failed the test gauge so were culled and surplused to the civilian market. They looked as new. One wonders why they weren't gauged and culled at the beginning of the FTR process instead of afterwards.

[Surpmil]

Since I've never used one, I'd let Peter or someone else with experience answer just exactly what the test bolt does and how it works. Most receivers I've seen that are known ZF have worn bolt ways which usually means the sear is dragging or even catching on the LH locking lug. It's a given that the hardening in the sear lug recesses is most likely very tired when the weapon has seen such extensive use. I've seen two No.4T rifles that were both marked ZF because of worn bolt ways. The interesting part is that both rifles had been through complete FTR in the mid 1950's then must have failed the test gauge so were culled and surplused to the civilian market. They looked as new. One wonders why they weren't gauged and culled at the beginning of the FTR process instead of afterwards.

Indeed. But then our government is known for spending vast sums refurbishing items only to sell them at knock-down prices shortly afterwards. Perhaps other governments do the same!

I must say I've always wondered about the wear to the recoil lug faces question. Looking at the hardening marks on the left receiver/body walls the electro-hardenings looks as much as 1/4" wide at times and never less than 3/16". Is it really possible to wear through the hardened face and how does one detect that? I wonder if actual stretching of the body could be a factor.

[Peter Laidler]

You'll just have to believe me Rob that the hardening of No4 bodies is a problem and is always tested during Base workshops. Once it's gone through, that's it - scrap/DP etc etc! It#s not just worn through locking lug hardness that the bolt will test for. Lots of other things as Brian has suggested

I have mentioned this many many times on the forum and during the trials to test the feasibility of a No4 bolthead just to save needy bodies. The calibrated gauge bolt was the final arbiter. After all, if the examiner didn't have a gauge standard bolt, all that he could have was a gauge standard body on which he'd have to breech up the barrel from the rifle he was testing.

Brian asks why it would appear that a rifle iis ZF'd seemingly AFTER it'd been through the process. That's easy. Somethimes you have to repair the rifle to ascertain whether your work will correct a fault. Do the work, re-test and it if still fails, that's it.

[Surpmil]

It#s not just worn through locking lug hardness that the bolt will test for. Lots of other things as Brian has suggested

Would you care to expand on what those things are Peter and how they are checked? It seems to me to be a good thing if more of this knowledge is in the public domain, lest it be lost to time.

[Peter Laidler]

Another important one was worn bolt way. To test whether the cocking piece will run into or touch the nose of the sear. This fault can only be repaired once. A second time and the body is scrap.

I mention elsewhere that this test was relaxed during L42 conversion as many No4T bodies were within the failure range