I've had good luck with LC M855 and Serbian SS109 out of my 16" rifle, but I think it's mainly a fluke with a couple consistent lots.
We're a bit spoiled in that a 1 MOA or better gun is pretty customary with decent off the shelf ammo. In the military a 1.5 MOA or better rifle is a specialized gun with specialized ammunition.
If you think sporting ammunition is more effective or better quality than U.S. military ammunition that soldiers lives depend on, you are mistaken.
I'd bet lunch.
Not knocking the military industrial complex. It was a point of pride for me that the artillery fuses I inspected weren't going to fail because I missed something. I was even more dedicated to making sure the ( redacted ) was perfect so the guys flying ( redacted ) wouldn't miss. ( Pretty sure it's not classified anymore... but )
However....
QC for mil-spec small arms ammo in the U.S. is very, very good. I'd trust it to function. If I had a choice between 2 boxes, one from Lake City and one from Black Hills, I'd chose Black Hills. I think they put a bit more care into it, and it's proven. ( at least to me, and the government )
Hornady checks concentricity on a percentage of their ammo. Don't recall that spec in Mil-spec, but I could be wrong.
If it's "bob's valley reloaded ammo" ( available in a local town... I changed the name ) then... give me mil-spec. American please. I'd probably trust Brit or Aussie almost as much.
Doesn't mean I wouldn't use Singapore made ammo for practice. Or Russian. For practice.
Now.... More Effective? Unfair. To mil-spec. Effective is, "does it function, does it hit where aimed, ( how close enough? ) and does it do the job when it gets there.
And Geneva Convention ammo is deliberately not very good when it gets there.
Take your standard issue 5.56 ammo, and Hornady TAP For Personal Defense.
Issue rules on defeating armor. Might be close on Kevlar, but on hardened metal plate? Issue. All the way.
Issue won't expand. Against the spec. There are rules.
Hornady TAP will. Pretty darn reliably. Not even the same room on terminal performance. No doubt which I'd rather have if I need to shoot zombies, or terrorists with machetes running through a crowd. If my enemy/target is in Soviet issue body armor? Mil-spec, all the way.
And, yes, apples and pears.
There are a lot of things where the big budget ( lowest bidder ) military gear is better than a civilian can buy. Decent, tough, heavy camping gear. ( are you on your motorcycle, or walking? ) Jet fighters. Those diesel dirt bikes. ( are they selling them to us yet? )
OTOH, we have biolite stoves to charge our tablets while cooking with twigs, camping gear that makes shelter halves look medieval, and removable glass cockpit modules you can stick in a purse that can replace an entire vacuum gyro setup in a C-5 Galaxy.
M855 was designed as machine gun ammo for the FN Minimi/M249 SAW.
M855A1 is supposed to be more consistent. I would not put much faith in the Army's sales pitch. Reportedly they used 1/8 twist stainless match barrels for their advertised results. Actual field testing I've seen shows 3-5 MOA.
Military ammo is designed to be reliable and weather proof. Even the specialized sniper ammunition lags behind commercial offerings. The priority is reliability over absolute precision.
Military ball ammunition of any sort tends to fall behind commercial offerings more often than not in accuracy. That's pretty much a given.
Of course the shooter is the main component. We're taking gear, here.
In my days I saw a couple M16A2's blown up by a bad lot of ammo. One was practically right next to me.
Nothing was recalled. It was used until expended
Whenever people talk about how perfect everything in our military has to be I cringe a little. It is all maintained and run by peers and managed and funded by bureaucrats.
Efficient, yes. Best? For issued gear, maybe...when new...though we still had way too much Vietnam era gear and ordinance when I was in.
Yes. All the political anti-gun activism has has sprung entire industries and movements.
Some hollow legislation has been passed in the past few decades, but concealed carry pistols, right to carry laws, and sporting arms have become the norm despite all the opposition.
1911's are awesome. A 106+ year old design that is still just as relevant as it ever was.
Like the Ma Deuce, they are brilliant enduring designs that have no end in sight.
Full registration and serial numbers for each one.
The perfect Government program.
Lots of money and personnel, lots of managers, lots of employment for people who, frankly, couldn't handle a job at the DMV. Pretty much a permanent organization since they already fake crime stats in England to fit the needs of the politicians. And utterly useless.
I've been playing with the AR-22 with the new barrel. It does alright.
On the left is the original CMMG barrel. That's one of the better groups at 2.5." Center is the replacement barrel. That's a typical group at 1.5." On the right for comparison is the S&W 15-22 at 3/4." 20170616_004441 by Slick_Rick77, on Flickr
When I bought my much missed Varminter, just for giggles, I did a test of the fanatic "clean between shots break in" myth.
( long rant with too much boring detail deleted, almost as long as the break in. You're welcome )
Ended up that the Premium break in ammo was not stuff the gun liked, and after a really slow day cleaning & shooting, it hadn't improved much and it wasn't very good. Threw in Winchester White Box practice ammo and groups shrunk. Dramatically.
So.
You can never tell what ammo your gun will prefer.
I probably utterly wasted my time since I couldn't prove if the fanatic break in was worth anything.
IMHO Generally. .22 LR is darn picky on ammo. Can't claim it's the worst, but automated manufacturing and small powder charges?
Guns & Ammo did a .22 test a month or so back. Used a proper match rifle and the results were interesting. Some of the cheaper stuff was impressive, and some "match" grade, wasn't. And yet even they aren't able to recommend a brand and version for your gun. But they did do a lot of math, so you could pick the bargain brand with good consistency, to bias your search to the most likely best bargain.
I've had best luck with Federal Champion and CCI Mini-Mags when it comes to bulk stuff. I've never seen the need or utility for expensive match grade ammo just to squeeze out a fractional gain in accuracy.
The exception has been my 10.5" AR, just to get an idea for its outright potential. It dispels the common myth that short guns lose accuracy or utility. As long as proper stabilization is maintained it works quite well. All that is lost is some range and terminal ballistics. The latter can be compensated for with careful ammunition selection.
None of my 22's have been very ammo picky as far as function or accuracy. In the case of the original barrel in the above gun it all performed miserably.
I approach firearm or barrel break-in the same way I do vehicle break-in...use it as intended without subjecting it to undue abuse.
I used to clean my 22lr barrels religiously until more prominent shooters have suggested cleaning as little as necessary. It's the same tactic used by adult airgun shooters...clean only when there's a detectible loss in accuracy. Makes sense to me.
My point wasn't that premium match ammo is necessary. It's that bargain stuff can work as well. But you have to test it yourself. My method is to buy a little of a bunch of types, preferably on sale.
For plinking, my favorite sport, I look for best accuracy for the buck.
My Ruger 10/22 was a bit picky. If I ever get it back I'll rebarrel it.
I have a whole rant on how the five cent deposit coke can is the best target.
( a bit smaller than a deer heart or chuck torso. Immediate feedback because they move. Easy to clean up. ) Never glass bottles.
The bore snake changed my attitude on cleaning. One pass good works for me. I have an expensive composite one piece rod I bought for my AR.... and bought a bore snake while I was waiting for Midway USA to deliver. Never used the rod.