Now that I've retired, I've been able to spend a lot more time at the range. Something that has become more apparent to me is how some rifle calibers appear to be more "picky" when it comes how they perform with different loads. Granted, there are many variables that can create differences in the performance of one load or brand of ammo to the next. Still, I have found the range of those differences seems to differ from one caliber to the next. For example, I've found that both by Remington and Weatherby .270 rifles produce individual groups with the least amount of variance between them when using different loads. In other words, the distance between the center of separate groups, each group made my a different load, is the least for both my .270 rifles. My Winchester 25-06 is a close second, with my 30-30 and .243 rifles being a little less in performance. Surprisingly, it's new 6.5 Creedmoor that takes up the rear in it's ability to produce groups that are close to one another. Don't take me wrong, the Creedmoor produces some very tight groups. However, the groups made with different loads are no where near as close to one another as those made with my .270 or 25-06 rifles.

I know that a lot of effort was put into perfecting the Creedmoor as a long-range target round, and at first glance, the geometry of the round is what catches your attention. The bullet appears much longer for its width as compared to the more common calibers. At first I thought this was more a matter of how the bullet is seated in the casing, which may in fact be the reason for it. Still, I have to wonder if the Creedmoor design lends itself to requiring a specific load to achieve such long-range accuracy. Shoot anything other than what it shoots best and significant sight adjustments are needed, even at much closer ranges.

I know that everyone and their brother recommends the Hornady 143 grain ELD-X load for the 6.5 Creedmoor, and it shoots very well in my rifle. However, is this the only load anyone should shoot when using the caliber?

I've had many 22 Hornets, everyone of them picky as can be about ammo.

Too many variables with factory ammo to even think about it. I reload for all of my centerfire rifles, and without a doubt the pickiest is a $3000 custom in 25-06. It likes one particular bullet with one particular powder and charge. Vary even a little bit and groups go to carp. Now there might be another load out there that it likes, but it nearly wore me out trying to find this one.

Least picky is probably my Tikka CTR in .260. Last year I decided on a whim to run some of my target loads that I had worked up for a different rifle through it. Ran it out to 1000 yards and it stayed well below MOA.

I swapped a rifle for a 6.5 CM Bergara. The previous owner had problems getting the accuracy he wanted, but I was willing to give it a try. Since I shoot mostly 120 gr Nosler BTs in my 260, that’s what I loaded up (over H4350), and I found a super good load. For a long time I had meant to reconnect and ask him what he had tried that didn’t work so well, but he called me first. He had been loading up bullets in the 140 gr range, and the rifle apparently didn’t like that bullet weight.

As for me, my Hawkeye in 223 has been a tough one to figure out, though some of the problems were due to bad scopes (2). Lord knows how many rounds I have run through that rifle. As much money as I had in it, I was still thinking about selling it at a big loss and getting a Tikka. But, I have the magic loads now, and I’m real happy with the rifle.

It was after changing both the scope and bases on my Creedmoor that I realized the issue wasn't me or the rifle (Savage Model 110). I'll just have to stay with the 140 grain ELD-X loads unless I want to adjust the sights for less expensive ammo. The rifle groups Remington, Federal, and Winchester ammo almost as good and plenty good for taking a deer at 200 yards or less. The center POI is just much different for each group.

Since we’re going on general observations and not facts I’d say anything that’s not a .473 bolt face is pickier.

I’ve only had one rifle that just flat wouldn’t shoot. A Sako Finnlight 243. Tried tons of loads and smallest group was about 3”. After fordamnever Beretta sent me a new one and it shoots lights out. Christmas lights.

generally speaking I think it is more a function of the rifle in which a round is chambered along with the ammo, than the cartridge selection.. Like the one Aggiehunter03 wrote about something is wrong there.

I've had more trouble with 25 caliber rifles over the years than any other caliber. Had several Ruger 25'06's in both a bull barrel VT & a couple 77 Tangers, then in 1979 I bought a USRAC M70 FWT Roberts that with it's preferred ammo in WW 100 grain Silvertip was fantastically accurate - I won lots of $5 bets about being able to put my initial's on a business card at the 100 yard backboard - while groups in anything else gave dependable albeit small Minute of Deer shotgun patterns, with RP 117gr RN the absolute worst. Not much Rbt's ammo on the market in the '70's & early '80's to choose from after the WW ST's were discontinued.

# 2 on my most difficult caliber for accuracy list would be 300WMg. Again in RP ammo the groups were shotgun patterns in several brands of rifles from Browning, Ruger and Savage that I owned in those days. I had "inherited" a leftover case of WMg RP ammo after a Shooting Event in Houston one time, and finally pulled the bullets to salvage the brass rather than shoot that ammo at game. Years later I did have a M70 SS Classic WMg with a poor trigger that was more forgiving but again generally detested RP ammo that reliably gave only 2-3" patterns in it at best. My non cataloged SAKO Classic Grade WMg would tolerate most any ammo with decent MoD sized groups, but generally not give great groups with any American factory ammo from the 1980's, but would consistently shoot teeny tiny groups with it's preferred handloads or any SAKO & Norma factory ammo I could find.

The very best rifle for Day 1 out of the box accuracy I ever owned was a NIB CZ 550 9.3x62. Shooting a cheap Speer 270 gr SP over any load of RL15 on the chart, it's 1st 5 rounds were under an inch, with 3 rounds touching at 100 yards, and would duplicate that or better in Nosler 250's & 286's at max loads. That rifle would shoot almost anything well including Privi & the other Serbian made stuff , and some stuff Lot's Mo Bettah than I was capable of with some other shooters behind it.
Ron

I can remember all of them but for my REM 700 sendero in 270 Winchester I had at one point 7+ loads comprised of factory and hand loads that would all shoot through a quarter sized hole at 100 yards without adjusting scope or point of aim.

Some I remember were
130 grain bronze points (factory load)
130 grain core lock (factory load)
140 grain ballistic tips (factory load)
150 grain partitions (handload)
90 grain hollowpoint (handload)
110 grain softpoint (reduced handload)

I still load and shoot the 150 grain partitions and 110 grain reduced load. Wife shot a doe with it this weekend.

I too found my Winchester Model 70 25-06 prefers 100 grain bullets over the 120 grain loads I also tried feeding it.

My 26 nosler was the hardest to get a load worked up for.

Mine is a 257 Roberts. Someone here suggested 110g accubonds, nosler trophy grade ammo. Shoots great now

I find that Bullet/Powder combos can be picky, but if I do a little research and figure out what folks are having success with, things go smoothly.

A sako finlight in 300 wsm I played with