Question on 7.62mm x 51mm vs .303 BRit

[ssj]

Really? I'd say that was merely much-repeated myth that simply isn't supported by any evidence.

7.62mm/.308W No4 rifles have been around for decades, and there is no data around to suggest they are in any way inadequate. I had one Envoy accompanied by a log book showing over 9,000 rounds of 155gn match ammo - that one was still tight on a "0" bolt head - and another where the owner had really been stoking it with 168 and 190gn bullets for 1000 yds - ditto on the bolt head.

My experience with 303 1943 and S&B brass is with a low load of 38~39grains of 2208 the stretching is minimal. Take it above 41grains of 2208 and you see the case stretching. Any higher loads ie above 43grains and cases tend to fail in one use. I know this because my digital scale started to read low, (38 was 43) and lower (38 was 47) When I picked it up my no4 wasnt happy. The bolt will now close on a no go gauge and and I had 4 out of 6 cases fail in one go. Quite severe in <50rounds. On top of that I find above 41grains to have to full size as opposed to neck sizing more frequently ie every other or you cant close the bolt on a round. Stretching is typical according to NZ shooters, especially so when they 308 converted their no4s.

Have a look at the 308w ballistics at 1000yds say for 155gr HBC projectiles for (palma TR shooting). To keep them super-sonic out that far needs a min of 45gr+ of 2208. You are going to have to push a 303 a long way to get the same and the BC isnt going to be that good. I wouldn't knowingly fire a 303 that hot.

Army loads are quite moderate by comparison.

---------- Post added at 02:02 PM ---------- Previous post was at 01:54 PM ----------

The OP is talking about a purpose built match rifle. The 303 in that configuration will hold its own anywhere.

If its a purpose built say Barnard type action chambered in 303brit, I would still say no. If as was commented its based on a no4 action and 1000yds and for match shooting trying to keep it supersonic, no.

I think sometime ppl just dont appreciate how much risk they are taking when they load up guns and especially old guns to try and keep pace with modern match actions. In the last year or two Ive seen enough abused P14, Omark and other old match grade 308w actions that show signs of severe stress not to want to see another.

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[ireload2]

Case head separations abound with the #4. If you are use to shooting a front locking bolt gun the #4 seems flimsy.
One of the contemporaries of the original Lee-Enfield - the 1891 Mauser is much more rigid and gives much better case life.
I have bought tens of thousands of once fired cases in more than 50 different chamberings. The .303 is the only round that I have ever seen that separated with new factory loads. That includes the excellent .303 cases that Norma made.

Probably the best way to rebarrel to a .30/.303 is to pick out the brass, dies and bullets you want to use.
Have a custom reamer made that provides a chamber that is a very close fit to the factory case head base and those cases sized in your loading die.
Match the diameters and the head to shoulder dimensions. Case life will be much improved and so will the precision of the chamber to ammo fit.
In addition the reamer can be made without throating so throating can be varied according to the bullets to be used.

Really? I'd say that was merely much-repeated myth that simply isn't supported by any evidence.

[Bindi2]

The OP is talking about a purpose built match rifle. The 303 in that configuration will hold its own anywhere.

[Bruce_in_Oz]

I suspect that the matter of "head separation" has less to do with the action than with the "interesting" qualities of the original "issue barrels.

Much of the brass fired from bog-standard Lee Enfields shows noticeable expansion and distortion at the web of the case. This indicates excessive chamber diameter, (or seriously undersized brass, or both). If the taxpayer is providing the rifle and the ammo, most users disregard this sign.

If, like most of us, you are forking out hard-earned for your weekend fun, it is a problem.

NOTE: If you look at the SAAMI data for the .303 and compare it to the "nominal" specs for a "military" chamber, there is not much difference.

HOWEVER, it is fairly clear that a LOT of "issue" chambers are oversized. The idea seems to be two-fold:

1. Add a little "clearance" for battlefield "fouling"; mud, etc.

2. Reamers are expensive. ORIGINAL Lee Enfield chambers were NOT cut with slinky, one-piece reamers a-la Clymer or P. T. & G. The process involved several different tools in a sequence. Ultimately, if the cases did not rupture on firing and were easily extracted in one piece, all was good. There may also have been a tendancy to start with reamers "a little oversized" and re-sharpen them until they were too small to cut an acceptable chamber.

Additionally, unless you have one of the rare Lee Enfields that has never been out of its wrapper since it left the factory, there is NO guarantee that someone, somewhere, has not "freshened up" the chamber, to assist extraction and to pass "visual" inspection in some dire outpost.

Cartridge brass is there to house the other parts of the round in a neat, water-resistant package and to SEAL the breech at scary pressures. That it is potentially reusable, probably did not weigh heavily in the considerations of designers and logisticians.

If you are prepared to be gentle with the once-fired cases, they will last for a surprising number of reloads.

Try setting the full-length sizing die back a bit to do a little less "squeezing" of the body, and then run the partially sized case through a neck-sizing die that JUST nudges the shoulder. A bit of experimentation should allow you to set the lock-rings on the dies for optimum dimensions and easy repeatability.

If you make up "match" loads for a few different rifles, batch the brass (and loads) for each one. Yes, it is fiddly and requires a little "stores management", but each rifle will have subtle differences in the chamber AND in its preferred loading. This way, you extend the life of your expensive brass and have ammo optimised for your goodies.

Either all of that palaver, or just enjoy shooting the damn thing and grin and bear the cost of new brass on more frequent occasions.

For those who have a pallet of Mk7 ball stashed in the shed, all you have to worry about is throat erosion..................

As for 7.62; "NATO" ball goes subsonic before it gets to 1000yds. Attempting to load it so that it is supersonic at that range is an exercise in futility; you cannot safely get enough powder into that case to propel a decent bullet fast enough to achieve that result. Long, slinky bullets are only a partial solution, as they tend to be heavier AND potentially take up space in the cartridge case that really needs to filled with propellant. If you extend the barrel to 34 inches or some-such, it will have the rigidity of a piece of cooked spaghetti, or be so heavy that it will require a full-on carriage and trail. Besides which, if all of your magic powder is completely burned by the time the bullet gets to 26 inches, extra length will just start to slow the bullet down!

If you want to shoot little groups in the "X"("V") ring at 1000 yards, get a .30-06 / .300 WSM etc. or one of the "hot" 6.5mm or 7mm jobs. And get ready to empty your wallet!

[Peter Laidler]

That reply should be made compulsory reading for everyone in the shooting world BinO. A short sharp lesson in the bleedin obvious for those who need to keep their shooting feet on the ground and start looking at the real world how things are and not what you want/think them to be. GREAT choice of words and answer to the whole thread ...........

[CINDERS]

To me I agree with Bruce I shoot/shot full bore with the Palma @900M we reload ours with 44.* gns of AR 8208 or AR 2208 (Varget) 46.*gns with 155.5 Bergers these are pupose built actions in Single shot my wife has 2 Banards and I use a Neilsen all with match grade Kreiger 30" barrels but my rifle I love shooting is my 6.5 x 284 Savage with a 30"HART Brl 140gn Berger VLD with a BC of .612 very slippery pill down side barrels pretty tired by 1200 rnds I am on my 3rd.

To ssj you are a very lucky boy! imagine if you had been using a really hot powder like 06H (In another rifle of course with the scales out as they were.)

The three above weapons in 7.62mm are modest weapons if you want you can sink $5k in just an action Rock mountain I think, the 303 does not cut it anymore, but if your hell "bent" on doing one up get a really good one custom built by Purdey no they do shotties ummmm Holland and Holland would do you one for a reasonable fee. I did see a sequential pair of 600NE's by H&H for half a million dollars if that gives you a figure.
Build time would probably be 2-3 years so all set and done get it back to mil spec and have fun that way cheap as chips and dashed good fun you can increase the fun by using P.O.F ammo as they surely are guesswork rounds anyway that's my 5c worth like they said PL & Bruce put it into perspective,