Genuine R4 rifles

[WCC]

Here's a pic of the Nobleteq gastubes they were selling for LM4-6 rifles. You will notice the LM4 tube has the flange where the LM6 tube is likely a cut off LM4 tube.

It is also difficult to tell which parts were imported Israeli made and which were local.

A lot of the locally made parts I have seen have a diamond mark on them. You also see this on the locally made mags.


There's a very informative thread on the Galil vs R/LM differerences here http://www.uzitalk.com/forums/showth...s-of-pictures)

[ady]

Trick question: Can anyone here tell me the purpose of the ring around the front of the gas tube? It is correct that that the very earliest versions did not have that ring. It was very soon introduced though for a very specific reason.

I have come across two reasons for the ring around the gast tube.

1. For re-inforcement. I think the SA made gas tubes are thicker than the IMI made gas tubes. A dent to the gas tube would render the rifle inoperable.

2. There were reported instances of the locking lever on the Front Handguard Holder Assembly (No 5 on the exploded diagram) working loose under automatic fire, which in turn would loosen the gas tube. With the ring the locking lever can only move so far, but not become completely loose.

I can't remember where i came on these explanations, but they have stuck with me.

[Wanderin' Zero]

2. There were reported instances of the locking lever on the Front Handguard Holder Assembly (No 5 on the exploded diagram) working loose under automatic fire, which in turn would loosen the gas tube. With the ring the locking lever can only move so far, but not become completely loose.

This is indeed the reason that the "ring" was introduced on the gas tube.

[A-R]

Where were R6s used or issued?

Navy. Daphne class submarine crews. Can't think they ordered many rifles.

[A-R]

...2. There were reported instances of the locking lever on the Front Handguard Holder Assembly (No 5 on the exploded diagram) working loose under automatic fire, which in turn would loosen the gas tube. With the ring the locking lever can only move so far, but not become completely loose...

The handguard has no bearing on the gas tube. The gas tube is kept in place by the dust cover and can only slide back when the dust cover is removed (or damaged).

The gas tube ring does indeed prevent the handguard locking lever from loosening. I have never seen it loosening itself, but since it's kept in place by friction alone, that's a real possibility, especially under hard use and frequent cleaning. This was the reason for the change then.

I think the ringless gas tubes on the LM4's were simply old stock, that they used on the LM's since they were very unlikely to ever experience the problem.

[A-R]

Now that's interesting. Please post a few pics of your LM6 sometime if you have a minute.

Will see what can be done.

I'm given to understand that these are two different issues. Initially the R series had a round and relatively sharp faced floating firing pin. This sometimes resulted in slam fires. Then the elastomer bush was introduced. The maintenance schedule required periodic replacement of this (every five years if I am not mistaken) Subsequent to the elastomer bush setup story, the firing pin was later redesigned on the R series to make the face more square and it was returned to a floating design (sprung firing pins apparently don't work too well on the full auto setup). Its not clear to me if the shape of the aperture in the bolt also changed. I am also given to understand that somewhere along the line it it was discovered that removing the auto sear on an LM could result in slam fires, which is why many LM's have auto sears. As you know many of them also have sprung firing pins - something you will not find on an R series. I have also not yet seen or heard of a square face firing pin on an LM but then I haven't been looking very hard or asking either.

In the R series, a gun that ends A1 has the elastomer bush setup, A2 the redesigned firing pin.

My LM6 has the A2 mark on the barrel, under the handguard. (Serial no. on the gasblock.) It can with a floating firing pin with relatively large tip. Works great with milsurp Berdan-primed ammo, even the hot loads. With Boxer primers it frequently punctured the primers and the pieces of primer cup tend to blow into the firing pin channel and jam it. Jammed back, it doesn't fire, jammed forward it goes buurrp... Not nice during a match!

I obtained a bolt with smaller diameter sprung pin. Works perfectly so far, no piercings.

[ady]

Navy. Daphne class submarine crews. Can't think they ordered many rifles.

Were R6's not issued to the armoured (tank crews etc.) guys as well?

[A-R]

Were R6's not issued to the armoured (tank crews etc.) guys as well?

They used the R5. Paratroopers as well.

[spiggs]

[QUOTE=WCC;1106356]Here's a pic of the Nobleteq gastubes they were selling for LM4-6 rifles. You will notice the LM4 tube has the flange where the LM6 tube is likely a cut off LM4 tube.






My 6 has a tube like the centre one.

[ady]

I got a spare tube to be modified a little for my LM5 and it looks like the tube on the right, in WCC's pic above. It was probably a LM4 / R4 gas tube cut down.