Probably hand loading can be more accurate.  I am not set up for hand loading.  Looking specifically for your most accurate factory ammo for deer.

With my rifle today I was getting 3" groups at 100 yards:
Remington 700 xcr 30.06
Nosler ballistic tip 150gr

I'm not sure if it is the rifle or the ammo.  Could have been the shooter.  I have not shot any match (Sierra Match King) ammo from this rifle, so I don't have that baseline to compare it with.

I have a 7600  30-06 from 1996 that I use for deer hunting. For most of my life I have used 180 grain Remington pointed soft point Corelok. I buy it when it is on sale for around $10-12 a box.  Off the bench it will shoot 1/2” groups at 100 yards.

Cheap, accurate, and it works. I have never lost a deer.

You do have to watch for copper buildup!

There are tons of ammo out there. Expensive does not always equal better.

I’ve had Fusion 308 shoot MOA out of two different AR-10s.

Not to be overly negative, but what is "most accurate" in my rifle has absolutely no relevance in another rifle.

Some ammo brands have a tendency to be more accurate than others.  A great example is Federal Gold Match.  This stuff, and similar Black Hills loads, has a reputation for shooting EXTREMELY well.  Its well crafted, highly uniform ammo made with great components. The worst stuff on the market?:  Some third world mil surplus (anyone remember Guatemalan M193?) and the basic Walmart level Remington Corlokt.

Unfortunately, this is all a sweeping generalization that has no bearing or relevance on other firearms. What works in mine won't work as well in yours.  And its inconsistent rifle to rifle.  I've got a rifle that shoots 6.5 Creedmoor Hornady Precision Hunter 143ELDX  extremely well.  Of course this rifle also shoots just about everything else very nearly as well too.  On the flip side, I've had a Weatherby Vanguard II Backcountry 30-06 that I fed about $300 worth of every premium factory load on the market, and I NEVER saw a group (pattern?) better than about 3 inches at 100 yards off a benchrest.

There was a time when hand loading was the way to make "better than factory".  With the exception of the aforementioned basic loads like Rem's Corelokt and similar "value" loads, much of the current factory loadings tends to be quite decent.  I've seen Federal 45 ACP 230 loads clock 903, 903, 903, 904, 902, 903, 903,....   over a chrono.  That level of consistency is near black magic voodoo....

Overall, its VERY hard to make a crappy bullet shoot well.  In general, Ive found Nosler to make very good bullets.  Factory ammo loaded with Nosler bullets generally will be a good performer.  If your 150's were shooting poorly, your rifle may have a preference for heavier bullets.  try some 180's.  Poor shooting could also be the result of poor scope mounting (VERY frequent issue), a crappy scope (if its a $169 Walmart special you got what you paid for).

At one time Remington was a maker of high quality, accurate rifles.  Your Remington is a more recent offering, and recent Rems are, unfortunately, prone to some fairly shoddy workmanship.  I'm really hoping you got "a good one".  Buying a current Remington is often a little like playing Russian roulette....  Sorry.....

For what its worth, I'm using a 25 year old Rem Seven in .308.  Wonderfully light compact woods carbine, perfect for Adirondack big woods hunting.  I've been loading handholds and using factory in that for decades.  Nothing, no one single load, will consistently do any better than 2 MOA.  Its disappointing, but that level of accuracy is all this rifle is capable of.  I suspect the shitty synthetic Tupperware stock is a big factor.  It would not surprise me if your 700 XCR is the same ( a 2-3 MOA gun).

You've got no option but spend $100 on four different boxes of ammo, and bang away.  For 'cheap" ammo, federal fusion has been shooting well in various weights and calibers.  150 Noslers at 30-06 speeds are explosively opening.  Not a great choice.  Try 180 Noslers, perhaps some 180 Hornady SST....

You have to try many different flavors to find what your gun likes.

Me personally feel that's to light of a bullet for that rifle.   I would try some flavors in  180g.

Have someone else shoot it and see if they group tighter as well.

You have to experiment with different loads until you find what your rifle likes... then stock up.

Me? A Sako 85 Bavarian in 6.5x55 is the most accurate with 139 grain loads... even factory loads run into 1 MOA. Hand loads will put her into sub MOA.

My ar 308 was getting 1.3" groups with hornady sst165gr superformance. before i started working up loads. It got 3"groups with fgmm. 168gr

Like others have said, you're going to have to test different stuff to find what's most accurate. A load that shoots like garbage in one rifle might be amazing in another. I would stick with 150gr though. If you look at the ballistics within deer hunting ranges, the 150gr is typically the winner. The heavier loads may do better at long range, but deer hunting isn't typically a long range game. If your barrel is a faster twist than normal then look on the heavier end. Some rifles just like heavier loadings too. If either of those are the case, go heavier. Otherwise, stay in the 150gr range.

7mm-08 Remington Core-Lokt 140gr SP...the same 150gr in 30-06 is known to be pretty good.

For my Browning BLR 243... Hornady 100gr American Whitetail.  I had it shooting sub-MOA consistently at 100 yards.

For my Model 70 in 300 Win Mag, Hornady Precision Hunter 200gr ELD-X.  Also shot sub-MOA consistently at 100.

My circa ‘93 700 in 06 likes 165 or 180gr PSP Corelokt equally.
Like an above poster, I stack it deep when it hits $14 or less a box.
More deer taken with them than I care to count, from 15 to 300 yards. Never had any issues.

Now if we ever get to use semi-autos on deer here in PA, my 223 Wylde upper prefers 64gr Gold Dots over 8 other loads I’ve tried, and the 8.5” Blackout gets equal accuracy from Barnes TacTX (110) and Fusions, hates Winchester Deer Seasons.  I plan to try the new Sig all-copper 120’s to see how they perform...

Hornady Precision Hunter

All I used for many years, was ~1.5 MOA ammo in my bolt gun if I rolled the lead tips smooth, plenty good for my needs.

Current favorite in my 6.8 SBR is Hornady SST 120gr.  Would like to try some 95gr TTSX.  Think Wilson is the only one selling loaded ammo right now....

Or, better- 10 shots, 200y


For whatever reason, my rifle loves the 140gr stuff.

ETA I think I lied- I think the bottom group is 143gr hornady precision hunter.  That’s what I get for not having my sharpie that day. I confess to cherry picking a little on that one, I had several groups that day that were more like 2” but hey, gotta make myself feel good.

The 140gr “black” ammo shot similarly at 100y. Here is me shooting several different types of ammo (Lower right target is my first pic above)

Sounds like the test with different types of ammo is the way to go.  Thanks folks.

Yeap, try them all, and when you find one that works well, figure out the batch number and buy a bunch.  I've had different batches of the same brand/model ammo shoot differently out of the same rifle side by side.

For reference, my M77 30-06 generally shoots the best with Remington Cor-lokt ULTRA 150gr. Generally under an inch if I don't fuck it up.  It shoots the normal non-ULTRA branding remington ammo about 3-4" @100.

I hanve't found any other ammo that shoots as well as the Ultra.  Even the high end Nosler branded, Winchester Silvertip, Federal premium with high end Nosler bullets....I wanted the Nosler stuff to work so bad, but it just doesn't shoot well in my rifle.

X2.  My Ruger 6.5CM loves this stuff.

I shoot a lot of 30-06.  Without knowing your exact rifle, I would combine a couple of the previous suggestions and try Federal Premium or Federal Fusion in 180 gr bullets.

Federal Fusion ammo shoots excellently in every caliber I own. I understand the notion of "every barrel is different" but somehow that stuff just works for me consistently. I see many similar reports from others as well. Also had fine results (across all calibers) from Nosler BT and Hornady SST.

-Stooxie

I have had good success with Federal premium loads, both Nosler partition and Accubonds. Not cheap, but dependable accuracy for me, and usually just a little over MOA, or right at MOA.

I generally shoot three round groups in my thin barrel hunting rifles, and let the barrel cool between groups.

Of course 3 inches at 100 yards can work, but I am not happy with the rifle or ammo until I am close to MOA. If I want to take a longer shot at a game animal under field conditions, every variable needs to be in favor of success.

Are those one shot groups?  180grn/30-06 core-lokt ammo out of a pump rifle at 100 yards, and you are shooting 1/2" groups??  I am either really impressed or really skeptical.  Not sure which one yet........

Figure out what your gun shoots well, AND make sure it is capable of a clean kill on the deer you will shoot at the distances you anticipate you will  shoot them at.

The most accurate may not be the most deadly, or even remotely ethical/legal to shoot deer with.

I know which one I am.
That is not a consistent 1/2MOA gun, regardless of ammo.  Just like the 7400, the barrel is held into the receiver by one nut about an inch below the bore...

I have had some sub-MOA 3-shot groups from a 7400 with 150gr CorLokt, but nothing I would brag about, since that is the exception, not the rule.
With decent ammo, it's a 2-3MOA gun if you don't get it hot.
Just checking zero for my dad on my lunch break.

I heard they are even more accurate/consistent when you hang a sling on the barrel?

I know a bunch of people that own/shoot/hunt with them.  Never seen a single one shoot anywhere near 1/2".  But I guess there could be a freakishly accurate one that Remington accidentally let slip out of the factory.....

I've shot a box of Hornady Precision Hunter from my Remington 700 308 Varmint sps and my Ruger American.  Both rifles shot back to back sub MOA two 5 shot groups.  My Tikka 7 mag doesn't like the Precision hunter ammo.  I've hand loaded the Sierra Game Changer 165gr to shoot three rounds touching.  The barrel is very thin and heats up way to quick for a 5 shot group.

Federal Fusion has been surprisingly accurate for me in .30-06, and .223. Also surprising was the Rem CorLokt 165 gr in .30-06, both as factory ammo and the bullets in handloads, darn near as accurate out of my Sako A7 as 168 BTHP match handloads!

Other than those it seems to vary but I always try Hornady Custom or Fusion as a starting point.

There are two that have been equally accurate and precise in both of my Grendels.

120 gr. Nosler BT and 123 gr. Hornady SST.

I haven't killed a deer with either, but they're both well suited for that.

Corelok is available everywhere and usually on sale or rebate.  We say minute of deer.

3” groups at 100 I would guess your scope mount or rings are not torqued down. That’s pretty poor for that rifle and Nosler ammunition has been pretty good in my experience.

For me, its Hornady Black. I shoot a 6.5 Grendel for deer usually, and it was the first ammo I tried. When it shot ~.65-.75 Moa out of my gun, I figured I was done looking for a load.