Opinion on the British .303?
Do you like rimlock? I love rimlock. I like spending 10 minutes poking the magazine spring of my rifle because one of them slightly nudged above the rest and now they don't feed properly.
I'm glad I paid a dollar a round for this.
Before we had the L85 for British squaddies to pretend is good, we had the .303 cartridge. Brits would smile and laugh at us Yankees for not having "muh fast action" while they were pretending they remembered how to exactly load their stripper clips so they fed into their rifles properly. Meanwhile we just slap a en-bloc into a Garand and we're good to go. While every other nation in Europe replaced their ancient ammo with something better, Britain decided to stick with this. Slow burning, low chamber pressure, a pain to work in any semi-automatic system and with a whopping 26 variations in ammo type.
And you all call the Americans assholes for having A2-6's when the Brits have more stars than space for just one cartridge.
The mid 1880's was a weird time for military arms, as most nations began to figure out repeaters but were still limited by the concept of black powder ammunition. However, the tides were starting to shift to repeaters. Everyone saw Plebna during the Russo-Turkish War, wanted a repeater and wanted them now. Kropatchek, Vetterli, Mauser 71/84, everyone was getting on the bandwagon and England was not going to lose to that. So they turned to a trials process and the Lee won. So the Lee needed a cartridge, and so .303 was initially developed for that, combined with Metford rifling to reduce overall fouling in the bore. Naturally, the Lebel knocks out the need for that and so the .303 is swapped to nitro-cellulose, or Cordite as the Brits called it. While decent at the time, the Second Boer War showed issues with .303 that needed to be addressed. Namely the round nosed variants tended to drop off steeply, especially in comparison to 7mm Mauser. While they would address it with the Mark VII load, they also tried to experiment in replacing the cartridge with the .276 Enfield round. Then WWI happened. And then they just gave up on replacing it and it stuck around by proxy through WWII and into the 1950's, only being nudged out by 7.62 NATO and the SLR. Even then, it still vestigially survived with units like the Canadian Rangers, although finally replaced by the Tikka T3.
While not as obnoxious as other 1890's era rimmed cartridges like 8mm Lebel, 8x56R or 7.62x54R, .303 is still a pain. Ballistics aren't bad, 160-180 grain rounds, 2,500 Ft-lbs of force, but they're usually sub 3,000 FPS. Usually around 2.5k to 2.75k. Not exactly all that impressive or potent when .30-06, 8mm Mauser can slug up to 3k with certain loadings and hit even heavier ft-lbs of force. Plus other cartridges like 7.5 French, 7.5 Swiss or 6.5 Swede can hit similar numbers without rimmed ammo, hell shit like 6.5 Swede can match .303 for ft-lps and FPS with less grains too. And all of these cartridges I've listed are rimless, so they're much easier to load and run in other systems than .303. It's ancient in all the wrong ways, and if it wasn't for the Lee-Enfield memes, no one would care for this round anymore.