This is my 1st post here (1st post on any hunting/firearms site honestly).
Out of the gate, i'd like to mention that i'm not a complete NEWB who's seen too much Hollywood or read too many hunting magazines. I started shooting when i was 6, 'bout 4 decades ago, and competetively for a number of years when i served under Pres. Ronald Reagan and lived in Fayetteville, NC - go Red Falcons!!!! I know long-distance marksmanship is a life-style commitment and i shot simply for the joy of it (as well as prep for hunting season - whitetails were nice, interactive targets as well as good food!).
Anyway, i've had about a 12-year break from hunting and shooting and am thinking about putting together another long-range rig. I had a Rem 700 chambered in .300 Win Mag, 24" semi-custom full-bull bbl, Brown Precision stock, Mark IV Ultra 10x optic, Shilen 2-ounce trigger plus the "stock" trigger i honed and adjusted to 1.5lbs (yup, did a bit of 'smithing in there). It was a serious shooter.
With Winchester brass, 71.2 grns of Reloader 22 (i think - it's been a long time), 190gr Sierra MK's, and CCI Mag primers it would hold 5 shots in a nice little cluster avg. .225" at 100yds. Fortunately/unfortunately, i had a significant change in the trajectory of my life (tactical, professional, civilian 'marksmanship' came off the vocational table) and sold it before i got to see what it'd do at 1k and out.
So here i am today considering putting together another LR rig - strictly for hunting. I plan on using it for North American game up to elk. For larger species (or larger bears), i'll consider something with greater mass (.375 and up).
I have a donor action (my high-school graduation present - a Remington 700 ADL chambered in 7mm Rem Mag). I'm thinking to screw on a Lilja 416 SS 26" bbl (fluted w/ Sendaro contour), adding a Timney or Jewell trigger (still have the 2 ounce Shilen too) and putting it in a MacMillan A2 or A3 stock. I am undecided (but not too concerned) about which optic, though will likely use a Picatinny rail and detachable rings/mounts.
My dilemma is this:
Do i go with the tried-n-true .300 Win Mag (which i have a couple thousand rounds of experience with) or the wicked-hot .300 Remington Ultra?
There are a few questions for me sort out as well.
Q1 - will the .300 RUM even fit in my donor action?
Q2 - will the .300 RUM be a barrell-burning monster?
Q3 - is the .300 RUM recoil that much more punishing than the .300 Win?
Only i know this....though i'm reasonably OK with recoil, i don't wanna rock my fillings loose either...
Again, the plan is to use it for North American game up to elk - at "long" distances (as in i'd love to do some elk hunting 'out West').
I'm considering only the .300 Win or the .300 Rem Ultra.
I don't see why you would change calibers if you have so much saddle time behind the .300 you have. Make more sense to me, for you to leave it the way it is. You'll have plenty of punch for LR game.
The Win mag will work for what you want just fine . The RUM will up the power and trajectory
and energy if you want more and to tame the recoil just add a heaver barrel (1 pound more
of barrel weight more than the Win Mag will bring the RUM down to the same neighborhood as
far as recoil.
With a good quality stainless barrel ,barrel life will be almost the same.
I agree both will do well on elk for longer range, With your experience with the 300wm and the fact that you don't sound interested in a brake, I would say a 300 wm.
Heavy bullets in a 300 rum do give quite a bit more felt recoil, but as JE said a heavier rifle will help some with that. But consider the fact of carrying extra weight and weather or not thats something you would want to do.
Personally I would go 300 rum, just because they shoot exceptionally well, and are very easy to reload. I would also use a muzzle brake because it makes shooting a rum enjoyable.
I would stay with the 300 Win mag of the two choices. The RUM w/o a brake is not fun at all.
However, if you have a donor action I would recommend a 300 WSM over the 300 win. Here is why, 2-3x the barrel life and same ballisitics so no basic retooling your ballistics memory. You can run the 190s at 3000 fps+ and 210s at 2850-3000 depending on barrel and length. We have LR BR competition winning WSMs with 2500-4000 rds down the tubes. No Win Mags do that.
I would sell the original action bolt and go buy a Pacific Tool and Gauge (PTG) bolt from Dave Kiff with WSM bolt face and either the M16 or Sako extractor set up correctly.
No matter what choice, I would buy the PTG bolt and go with a Wyatts extended box.
The other stock to look at is the Manners stocks. Less expensive and faster delivery.
as for barrels, Lilja is good, Broughton, Bartein, Krieger, Brux, Douglas, Shilen etc are all good and will make a great shooting gun.