reloading and the 7.62 No.4

I started to answer a question from a guy about case life of the 7.62 No.4 but the thread was locked. I have no idea why nor was I part of any dispute that may have taken place...!!!!! :-)

In the interests of helping another shooter I can tell you that I use a 7.62 No.4 for Service Rifle competition and shoot approximately 2,500 rounds every year from my 3 rifles.

I use winchester brass, sierra 155 grain matchkings and (what is known in the USA) AS Varget...or our 2208. I wont tell you the load but it is somewhere between 42 grains and 44 grains....

I full length size cases each firing, for surety of feeding and extraction...smooth bolt action etc.

I get about 3 to 4 reloads before the shiny ring appears about 1/2 inch above the case head that tells me there is an incipient head separation imminent....then I throw the case in the scrap bin... So expect 4 firings per case....full length resizing...before throw 'em away time...

Now you MAY be able to get much longer brass life by only neck sizing....but I prefer the sweet certainty of feeding and extraction that comes with the full length sized case....rapid fire is a large part of most of our service rifle shoots here in Oz. So the thing JUST HAS TO feed and eject with no hang ups or you lose matches... :-)

As a final note...i have tried the so-called 'better' brass...such as Lapua.....or the other end of the scale 'military' spec stuff.....ok they have thicker brass....but even with full length resizing I have had cases stick in the chamber and the extractor pull over....fatal in service rifle competition....no such problems with win cases so I've stuck with them.... The Lee Enfield isnt all that strong in the primary extraction department....and (experts tell me) the springing or stretching of the rear locking action tends to shorten case life.....

In the US Winchester has a reputation for having thinner walled but harder brass. In conventional bolt guns with tight chambers Winchester brass will often take higher loads than other brass without sticky extraction.
This is due to the hardness of the brass and it's greater internal capacity.

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Originally Posted by whiterider

I use winchester brass, sierra 155 grain matchkings and (what is known in the USA) AS Varget...or our 2208. I wont tell you the load but it is somewhere between 42 grains and 44 grains....

I full length size cases each firing, for surety of feeding and extraction...smooth bolt action etc.

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Your load is similar to mine, 168gr SMK, Norma Cases, CCI BR-2 Primers and 43gr of Varget. I also full length size for the same reasons. :)

One thing that came up into my head is some of the hammer forged barrels (snake skin models) have tighter then normal bores, mine measures out to 0.307" not 0.308" which can squeeze the bullet, so just like any other firearm you should reduce the load if it was originally developed with a "proper" on size bore. :)

Dimitri

150-155gr, IMR4064, Rem9 1/2(usually), boxer primed L2A2 or fed. match cases. Neck sized 2/3 down the neck AND body sized with Redding die that does only the base and if req. the shoulder. Use redding competition neck sizer w. the bushings to keep from over working the brass.
The L2A2 cases are 1990 vintage Radway Green, earlier and later ones all seem to be Berdan primed.(?????)

I know nothing to do with the topic, but couldn't help it !

Can anyone tell me anything about these Lithgow conversions, I cant seem to find any info on them?

Thanks

Andy

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Originally Posted by AndyGC123

I know nothing to do with the topic, but couldn't help it !

Can anyone tell me anything about these Lithgow conversions, I cant seem to find any info on them?

Thanks

Andy

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Is there something that makes you think its a Lithgow conversion ?
The photo shows a Savage.

Australia evaluated some No.4 actioned 7.62 Conversions and Savage No.4 rifles have been mentioned as being used by rifle clubs.

The only government 7.62 conversions I've seen mentioned were of No.4 T rifles or L42 type rifles that may have been purpose built. I believe Australia chose not to adopt a conversion for sniping purposes.

Whether a conversion on a Savage action would have been done by Lithgow would be hard to say.

From Savage receivers I've seen I think it would be the least suitable for conversion, at least the Mk I* models.
The rifle shown appears to be a No.4 MkI with earlier takedown method with catch.
Some Savage early versions were converted to T models.

First I heard of Savage rifles having a problem with the bolt head rotating out of the track was a short article in the American Rifleman from a member of a rifle club which I think was in Australia.
My own Savage No.4 has the begining of that problem and it seems to be a matter of the rear receiver wall having spread just a hair, enough to allow a vertical tilt of the bolt as it moves forwards if the magazine is empty or no magazine is in place. The bolt head tilting down causes the underside of the lug to touch the bottom of the track and be levered up out of the track.
Photos of other Savage actions with chipped tracks show what appears to be too much material removed around the cut out for the lefthand magazine feed lip. DP'ed magazines often show signs of the lefthand lip being worn down or damaged by contact with the bolt face.
Bending the LH lip up enough to contact the bolt as it reaches the opening in the track prevents my bolt head from rotating out of the track with an empty magazine in place.

Ireload suggested that poor stress relief may be the cause of the receiver wall spread, this sort of spread was found on some No.5 carbines after hard use.
The loose fit would not be immediately noticable if not for the Mk I* modifications opening in the track.

The AIA receivers have a beefed up bolt head lug and track, probably to prevent this sort of malfunction.

>>>I use winchester brass, sierra 155 grain matchkings and (what is known in the USA) AS Varget...or our 2208. I wont tell you the load but it is somewhere between 42 grains and 44 grains....<<<<

From my view there seems to be some very well informed loading going on here.

1. The .303 and the 7.62 Nato cases have very similar water capacities.
As you might recall from physics and especially chemistry PV = PV.
(With P = pressure and V= volume for gas.)

2. The manual data for the .308 Winchester (not talking about 7.62 Nato here) is about 10% higher than .303 data with similar bullets weights and Varget.

3. Whiterider's load is in the range of top loads for the .303 with a similar weight bullet.

His advantages are the use of more readily available 7.62 brass (AKA .308 for brass identification only), a closer fit between the chamber and the brass and a much larger selection of bullets.

Apparently from collectors I have spoken to locally, the funny looking letter in the circle indicates a Lithgow conversion.

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Originally Posted by AndyGC123

Apparently from collectors I have spoken to locally, the funny looking letter in the circle indicates a Lithgow conversion.

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The circular stamp near the charger guide on the left hand side receiver wall is a type of proof stamp, indicating that the action has been "crack tested".
This seems to have been done to most Australian No 4 7.62 conversions; I believe it had something to do with the safety regulations of the NRA rifle clubs at the time.

There are two variations of this stamp, one has "L" (tested by Lithgow SAF) as the third letter, the other has "S" (tested by SPORTCO, S.Aust?).

The stamp does not necessarily mean that the rifle was converted by that factory, merely that the crack testing was done there.

When I had one of my No 4's converted in 1984, I mailed off the bare receiver to SAF Lithgow for testing, back it came with the stamp, ready for rebarrelling by my local gunsmith.