Are you going to reload for this new rifle?
Do you have an ample supply of slow burning power?
Are you building from scratch, starting with an action or are you going to buy a factory rifle?
Are you going to be walking/packing with this rifle...is weight a concern?
Are you recoil sensitive?
What kind of budget do you have for this rifle?
These are all just a few of the questions you need to ask yourself.
The 300prc is an "optimized" 300wm. It's NOT some magical physics defying super cartridge hornady made it out to be. The 300prc gets rid of all the so called "flaws" the 300wm has like the short neck and that "pointless belt" and chamber slop. I have a 300wm pre 64 model 70 with a hart barrel that I will be buried with. Shoots 1" groups @ 200yds with 180gr nosler partitions...... I haven't shot that rifle since I bought a 300prc. The 300prc can just do stuff with a 230gr bullet that a 300wm won't. Yes you can get a 300wm throated long and blablabla....but is it still a 300wm? Not if you are going by Sammi spec. 300prc needs a 26" barrel. Tons of options for production rifles from $500 to over $5k. Factory ammo is decent. Lapua and ADG and I think Peterson brass. I bought 500pcs of lapua and stopped worrying about brass. RL26 is your friend
300rum is a fire breather. It's gonna give you 200-300fps over the 300wm with the same bullets. It's also going to take over a pound of power to load 100rds. And without a brake It's going to kick in a 10lb gun. Needs +26" barrel. Not a lot of production rifles chambered in 300rum these days.
300wsm performs well with a shorter barrel and recoils like a 30-06 in my opinion. If I was doing a lot of walking I'd be looking at the 300wsm, 300saum, 300 max/mega because you can put it in a lighter rifle with a 22" barrel and shoot faster burning powers and not hobble performance much. S*** brass quality but available factory ammo. Not a heavy hitter in this conversation but it's freaking efficient. Factory options are hard to find and if i was going 300wsm I'd be looking for a tikka action and change out the bolt stop to make it an "extra medium" length action.
300 norma IS what hornady claimed the 300prc WAS going to be. You will need a lapua magnum size action and bolt face. If you go this route you should go with the improved version. Needs a 26" barrel or more. I've never seen factory ammo for this chamber. And factory rifles in 300nm ain't cheap.
30 nozler.... oh 30 nozzle'er. It's faster than the 300wm and 300prc. Cartridge was hamstring'd from the get go with its 3.340"c.o.a.l.. Cram a 230 in a Sammi spec chamber and say bye bye to that precious case capacity. Yeah you can Watts box a blabla123abc and shoot the long heavies. Brass isn't as bad as everyone says it is but it dang sure ain't the blue box beauties i run in 300prc. Factory ammo is going to cost you $5-7 per loaded round. Factory production rifles are expensive and not chambered by many manufacturers. This is a rifle that needs to be planned out and built from scratch to preform to its potential. Barrel life is similar to the 300rum.
300 weatherby... is a classic. It's got a cult following. 150fps over the 300wm/300prc. Ammo is expensive and brass is hard to find.
30-378 weatherby..... is well....like feeding a teenage mutant ninja turtle meth and crack and putting them in a monster truck with jet thrusters. Super fast. Super powder hungry. Throat erosion can be measured with a tape measure. Factory ammo was $150 a box....3 years ago! Factory rifles ain't cheap. I cut a white tail spike nearly in half with one. He was walking up hill up one side of a draw and I was on the other side 175yds away. I was shooting almost perpendicular to the top of his spine. Aimed for his withers...broke him in half at the spine between the shoulder blades. Realized that cartridge is what they used to sink the Bismarck and is better suited for medium sized aircraft and trips to jurassic park. Oh and it busted my nose once......wish I never sold it lol.
In summary. 300prc if you want a little improvement over your 300wm or 300NMimp if you want something a little more saucy. But I really think you need a 7mm
