I second all Long Path wrote as regards the ammo. Dunno know why but my two Enfields and a couple more I know of all like the 180 RNSP, and don't seem to care too much about what brand.
When I worked up my handload, I went with the Sierra 180 spitzer SP, to do the best I could to duplicate trajectory of the Mk VII ball military ammo--This to kinda match it up to the micrometer adjustable rear sight on my No. 4 Mk. 1 rifle. I have not been able to shoot it beyond 300 yards yet, but that's kinda academic, as I wouldn't shoot a game animal that far, even with the good peep sights.
Again agreeing with LP, I don't think most of us have any business shooting game beyond 200 yards with open signts.
One suggestion--I presume that you are well familiar with the sights and adjustments on your particular rifle. If it is possible, get an extra box of the Remington (or whatever commercial) 180 RNSP and sight to hit dead on at 200 yds, or 2 to 3 inches high at 100.
Also--Sight in with the hunting ammo. It would be mere coincidence if yout FMJ practice ammo hit same point of aim as the SP.
Take the steadiest rest possible, "go down on them sights," and P-R-E-S-S-S-S. The .303 Brit is a FINE old cartridge and is only a little bit behind the .30-06. And, up until the 1970s, probably took more eatin' game than any other cartridge above .22 rimfire.
Continue the tradition, amigo, and let us know how it went.
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