how do these two rounds compare to each other

Power vs speed. They serve very different purposes. Do you want to shoot big animals or far animals?

both haha im planning for a hunt in colorado for next year for elk and need to start looking into a bigger rifle

A 7 Rem mag is plenty adequate for Elk. However, if you like big guns, a 338 suits that niche.

Here are some things to think about. The comparison between rifle and shotgun isn't the best but it's a common reference point.

http://www.chuckhawks.com/recoil_table.htm

http://www.chuckhawks.com/shotgun_recoil_table.htm

Not to pick fly's outta te pepper but...
A. I'd really 'ov rather seen the comparison done with all 3 of those rifles weight being the same to get a IMO a better "feel" for true recoil....as they are really more comparable than not. There is no way to allow for the differences in "Gun Fit" and show them on a graph except for gross "all up" aka rifle/scope/sling/ammo weight

B. I'd also like to see a better representation of bullet weights used commonly in Elk Hunting...but I understand an appreciate the attempt at a closer comparison. IIMO I'd like to see the comparison chart use a 160gr bullet in the 7RMg vs the '06's 165gr'er, a 300WMg in 180'ger's and the 338WMg using either 210's or 225's to capture what actually being used, based on the elk hunting guys that I've talked to over the last 30/40 years.

C. the caliber spread illustrated was a good choice of commonly used calibers, but really needed to include the 300Wmg as well. After the 7Mag craze subsided a little with flatlanders establishing a reputation for not being able to adequately accurately shoot 7Rmgs in the late 70's and up thru the '80's when I got out of the Gun Bidnizz, the PH's and guides I talked to regularly in the Rockies all seemed to give me an eye roll of "Oh Chit" here we go again chasin wounded critters everytime some dude showed up carrying the Mighty Big 7. Interestingly 80/90% of my Denver/SLC based cohorts all shot 338's or 300Wmg/300Wby's (in a 4-5 to 1 ratio).

D. what cannot be shown on a graph is the Speed of Recoil Curve either. To me in guns in the apprx the same all up weight and same stock style & fit ... '06's are a little more solid thump than a 270WCF - my everyday deer shooter for 40 years, a 7Rmg has a sharper more pronounced faster heavy slap & stock shape becomes important to me, a 300Wmg is a little more pronounced thump than an '06 and a tad slower slap than a 7Rmg, and the 338Wmg in 225's is a little slower and tolerable but the same heavy thump as the 300WMg, that I shot and paired with a 270 for 30 years for my "go anywhere anytime" combo.

FWIW When Remmy used Kirt Darner & his Blue Mesa Outfitters advertising campaign they score more 7RMg sales then they expected and put the caliber on the map...My choice of a dedicated Elk Rifle by caliber would start with the 338Wmg/300WMg/7Rmg/30'06 1st to last.
JMHO and YMMV.

Any and all of these caliber will successfully kill Elk, and other similar sized critters, but The Great Average Elk Gun IMO is the 300Wmg in 180's or 200gr'ers for range and energy on target.
JMHO & YMMV
Ron

Why not a 300 win mag?

Ron, there are recoil calculators on the web that will do a good job making things more realistic. On the mobile now so if no one does it during the day will try to get it done tonight

No need to tote a 338 unless you're bear hunting, or you're a glutton for punishment. 7mm is more that adequate for an elk, and it flings a wide variety of readily available, high BC bullets. This is a no brainer.

+1

OP, buy a .338 just because you want one. I have more respect for that reasoning than anything else.

Other Online Calculators I've used are the Handloads.com site for drop tables & HuntAmerica's recoil calculator.

I really like the Handloads site ease of use, and from time to time built tables that are very close to actual field experiences vs preset BDC's.

As far a 338's percieved recoil being substantially worse than other calibers being discussed in ths thread, I'd beg to differ. Agree'd todays better bullets give the 7RMg better results than "back in my day" hands on but the same apply's to all the other calibers too.

Again my experiences were from the days when I had access to any caliber I wanted to play with in a quality line of rifles, and could write off ammo costs & range time on my taxes. I also had access thru shows and a sister warehouse operation staff and their Vendor reps in Denver for many years.

This was funny at the time... I was the only SM at our Carrollton warehouse, the Chapin, South Carolina based Ellet Bro's operation was all in house sales, but the Denver operation, Bern's Wholesale (& their super close ties to the largest retailer in Colorado in Gart Bros's) had 2 SM's, one in Phoenix and the other in the Denver warehouise with double the outside Sales staff I had. The SM guy in Tempe (Phoenix) was a close friend and had a long history as a successful Competitive trap shooter...but shot a BAR 7RMg at everything else from PDogs to Elk. We'd both won a trip from Weaver for an Antelope Hunt in Wyoming, and my 270 Ruger 77 matched his BAR's performance bullet for bullet in our tallest dog "sight in" contest on beer cans with a 20 round limit at futher and further distances...but his 465 yard "offhand" kill shot with his butt supported against the Longmont Co based Weaver Rep's ( & partime Alaskan Sheep Guide) Bronco's fender was only marginally longer than my 257 Rbt's 440 yard kill shot taken leaning across a fender and hood with an off hand shot. My Texas boss, who came from the Denver operation & Garts both before and after , was who started me looking at 338's, and opened my eyes, 'cause I also had had the uninformed opinion about the 338's way too heavy to use recoil. Later my 9.3x62 was the recoil compromise I liked best in 250gr, 270gr & 286gr'ers (never did see the need for the lighter 231gr Norma's available that'd run 2700+ fps) and fit nicely with the 300Wmg & 180's I'd been using for years.

The ancient old 9.3x62 (born the year before a 30'06 was accepted by the US Army) was good out to 350/400 yards at 2300/2400-2600+fps...or 338Wmg speeds in the upper end of the 338's bullet weight range in 250's...with a very pleasant to shoot recoil curve even off the bench.

Gotta keep an open mind and not get lost in the pre conceptions of other folks.
Ron

I had a 338 mag. would bring tears to my eyes when I shot it to sight in the scope. If you get one, have a muzzle break installed. My 06 kicked harder after that. Worth every penny.
Also the people next to you at the range will love you

Look, it's really simple. If you don't already know that you want/need a .338, you have no business buying one. It's not that a .338 has magical / overpowering recoil; they don't. That said, they have enough recoil that they demand a practiced and experienced shooter to aim them well. Do you really want to be "that guy" who shows up in elk camp scared of his shiny new rifle? If you think you might **want** a .338, buy it right now so you have time to get used to it well before your hunt. Should you decide it was a mistake, you still have plenty of time to trade it away and get something else before your hunt.

All that said, the .300 WM is a more versatile caliber and has cheaper, more available ammo.

In the end, it's good shooting with quality bullets that kills game.

I taught a big 14 year old son of another rep to shoot some guns one time, at a Shooting Expo Hands On Show, down south on Hwy 288 in the middle of nowhere north of Lake Jackson, gotta be mid '80's or so.

This very nice polite gentle giant of a young man was bored sitting in his daddy's tent Booth and was wandering up and down the firing line looking at all the other Reps shooters.

Anyway he walks in to my Booth and is looking at my SAKO's and ask's if he can shoot one of them. We were supposed to be charging a $1 a shot, but I was bored to tears that afternoon with the slow Show traffic and told him ...Son, you can shoot anything on the table, what do you normally shoot, he sez a 243.

Well this kid is just turned 14, 6'3"-4" and barely over 180lbs soaking wet with 36" arms...and I said lets start with this one - a 25-06 AIII, so he pops a few at the 50 yards targets set into the berm we are using for a back stop, and asks again what else can I shoot? We work our way thru the table with a 270.... a '06, ...a 7RMg ,....and he's shot the AIII SAKO 338Wmg twice of the 5 rounds I'm allowing him per caliber...while coaching him in his Off Hand techniques, when Daddy shows up mystified to see his kid putting up 5 shot groups you could cover with a 50 cent piece OFF Hand ...when he's never shot anything before except a 243 while seated at a bench ... and begins to freak out when he spots the big empty hole in the belted case laying on the ground.

Son sez, Hey Dad watch, grinning... and quickly puts 3 338 rounds on a 1" spotter at 50 yards ...and is PO'd that Daddy won't let him finish the table with the 375H&H that's the only thing the kid hadn't shot.

Now that kid was already a very large framed young man, who would easily carry 250lbs + full grown, and the old style SAKO AIII's were a heavy gun, but with a little coaching and no preconceived conceptions about recoil & wearing GOOD ear muffs, this kid was having a blast and never developed any kind of flinch or fear...even shooting a 338 WMg for the very 1st time....and kept the 338 Brass from his last shot as a keepsake.

We spend so much time shooting off the bench from a seated position that we forget the Recoil from a Field Position while Hunting is NOT the problem that it is from the bench doing accuracy ladders or practicing breath control and trigger discipline. BTDT I had fun, the kid had more fun than I did and Daddy was NOT Pleased but never said anything about it ever and really surpeised when I told him the kid had shot 30-40 rounds of Big Bore ...Off Hand ...very accurately ...in about 45 minutes...with a little coaching.
Ron

I'd like to revoke my initial statement. Be a real man, buy a .338. I'm not even sure if a 7 mag will kill an elk!

Should step to a .375, .378, or .416, no trifling with these small calibers. Wouldn't it be dang interesting if elk were as ill-tempered as Cape buffalo?

Wiley I cut and pasted from Chuck Hawk because it was easy. The reason I added the 12 ga. was to try and show that the recoil in a 338 isn't all that bad. If I needed something bigger than my 30/06, I'd go with the 338 WM, there just isn't a big enough difference to justify the 300 WM. A case can be made for going to 300 WM from the 308.

Nothing WRONG with killing an Elk using a 7RMg...but It's not the Giant Killer, Leaps small bldgs in a single Bound, Stops raging locomotives that it was promoted as, and somehow continues to be thought capable of...IMO there are better calibers suited for the job...with no more measurable recoil except in Off Season bored blather minutia on the Iternet.

Buy what you want, learn to shoot it accurately from Field Positions and go forth to LOAD THE ARK. But do not be afraid of recoil felt from sitting on a practice bench....unless you are as crippled up as I am at just past 70 with a history of shoulder & neck surgeries...and then learn to reload slower softer lower pressure rounds to ...as a old timey Gunwriter is famous for saying....Get Closer. Get off the gotta have a 500-700 yards Elk Killer. Folks in Scandanavia been killing Shiras Moose with 160 grain 2400fps 6.5x55's for over a hundred years. I suspect you could shoot one of those off your forehead and not get a headache...well mebbe a little one.
Ron

the 7 Mag will work (we have killed them with a 243) 338 will work. So will ALOT of others, We have 2 300 Weatherbys that have cleanly harvested good size Bulls from Colorado to New Mexico. 50 yards to slightly over 350 yards.
SO... with that said, IF you want a 338, buy one and run plenty rounds thru it. I don't like the 7 mag, but love my 300 Wby., it's a Ford vs. Chevy kinda thing.
Good Luck!

Mike, back in the day, before BDC's, Mil Dot's of any kind, turrets & Range Finders & G #4's were only on them furrin' reticles...I went with a "Paladin style Have Gun Will Travel" attitude back in those days, only because I was hunting all over the place by invitation as a guest, and expected to be an excellent shot as a Factory Rep.

I never quite knew what the critter was gonna be lots of times - a Trophy? Mgmt critter, Does Only, Exotics??? never the same thing twice... yadda yadda I discovered a 270 130gr'er in NPT, HRN & Speer, and the 300WMg 165gr'ers in the same bullets had about the same drop profile out to 4-500 yards, along with a 270 150gr'er & 300WMg 180'er doing the same thing using MPBR & a 200-250 yard Zero.

That way I only needed to train my muscle memory for ONE set of ballistics. Worked pretty good most of the time too. Lost some serious $bux playing a shooting game using cactus, stunted WTexas trees and distinctive rocks for targets one time on a new lease SWest of Sonora...with a bunch of ringer's at waaay past my practice distances.

You always BUY an Education to appreciate One.
Ron

If I ever went elk hunting, I would take my trusty .270 and never look back. I know it like the back of my hand.

There's the truth you're looking for.

Match the bullet to the game. Headstamps do not match to game like bullets do.