Your favorite or pet load should probably be the one your barrel shoots the best, not necessarily what somebody else's barrel shoots the best.

Here's how the Service competition teams do it - I originally wrote it to answer a 5.56mm question on another forum, but applies to them all:

Working up 5.56 Loads

It's been nearly a decade since I used an M16A2 in competition, so I'm not up on the VLD stuff - ask the guys on Jouster. I sold mine because it didn't perform at 600yds and out as well as 7.62 - but that's all changed - I was premature.

You need once-fired cases to set your sizing die. I like Lake City from Jeff Bartlett at GIBRASS.COM. He tumbles and swages primer pockets for a small fee. But be aware that you cannot mix mil and commercial brass - the military is heavier with less volume and higher pressures per charge. Sort your brass by lot, or buy only one lot.

I like RCBS sizing dies and Forster Bonanza BR seating dies.

Clean primer pockets w/Forster Lathe-type scraping tool.

Trim cases to uniform length, whether they need it or not. Case length not critical, just take a minimum amt off to get them uniform. Forget about neck turning until you get to the 1000yd line.

Set resizing die beginning at tallest setting by turning down in tiny increments until the case just fits the chamber - as tight as possible and still functions reliably.

Set seating die to insert bullets as tall as possible - just touching the rifling - but not so far that ejecting ctg causes the bullet to be pulled. With a magazine to fuss with size them so they barely fit. I use two lengths for competition - the long-range loads are chambered singly.

Make a primerless/powderless dummy(s) - mark w/fingernail polish - and keep it with dies as your length reference to be checked w/calipers. Don't fall in love with it - you may have to redo it after your powder test if it's set too long.

Reprime w/ CCI BR-4 or any small rifle primer. I like match primers. Just keep them consistent by not changing brands/types.

Your Ruger should be 1-in-10. But double check with a clng rod with tight brush - with the rifle in a vise, push the rod thru the bore and measure how many inches it takes to make a complete revolution - I clamp a yardstick to the vise jaws parallel to the bbl and mark it w/ a Sharpie.

That twist likes 55-70gr bullets. But 1-in-7 is best for the heavier ones. Boat tails are by far the best choice. I liked 69gr Sierra HPBT Match - and whether it's a soft point/superexpando or not doesn't mean much with this ctg on critters.

Assuming 69 gr bullets and Lake City Cases, make a dozen or so test ctgs beginning w/22.0 gr W748 in .2 gr increments = 22.0, 22.2, etc - all the way to max of 26.0 if you want to. Label them w/Sharpie. But watch pressure signs as you fire them. 26.0 gr is a popular match load in M16's that should print inside 1" at 100 @near-2800fps. Remember your #1 bbl is longer, so you should get more velocity w/less powder.

Swab oil from bore w/Hoppes followed by a dry patch - never shoot a bore/chamber w/oil in it.

Shoot them at 100yds, marking and plotting/labeling each hit w/spotting scope and scorebook - or go downrange each time if you have to. You will get 3 or 4 in one ragged hole - the powder weight in the center of that hole is YOUR load. That's the one your bbl shoots best, given it's individual harmonics. Forget about velocity.

Examine closely each case as it is ejected for flattened/blown-by primers, case stretching, and any bright ring near the case head (headspace excessive). The primers should gradually flatten until they practically melt into the case head with the hottest loads - but I don't recommend going that high - no need to and hot loads aren't as accurate.

Double check how your load resizes and seats/fires once more to make sure you are not too tight or too long.

Good shooting.