Norma 303 bullets for No4 use.

[Bruce_in_Oz]

I have tried "pulled" 7.62 x 39 bullets from several origins in .303. Being a much lighter bullet, you need to use a somewhat faster NC propellant than used for 174-180 gn bullets.

Then, once you have changed bullet weight (and "style") and propellant, the point of impact will generally be significantly changed.

Lee Enfields were BUILT AROUND the ammo; "One Round to Rule Them All"; so to speak.

Even the classic Oz "Heavy' SMLE barrel so beloved of vintage target shooters has a whole different set of behaviours compared with a FACTORY bedded standard barrel, Hence all of the weird "Bubba:" things done to the old girls to squeeze one more unicorn fart out of them. The standard rifle with original factory bedding, deliberately "loaded" the barrel to tune it for ONE cartridge; the ISSUED one. The bedding regime in the Heavy-barreled Oz SMLE sniper rigs is NOT the same as the standard rifle; NO inner band, for starters. And issued sniper rigs did NOT have the muzzle-hole in the nose-cap opened out with a rat-tail file to accommodate a piece of old garden hose as a "soft muzzle bearing", either.