[TMan51]

Find a better brand of ammo?

I've pulled the bullets on a few steel cased rounds. Some bullets won't even stand up straight on a flat surface. The FMJ stuff, the bullets are not even evenly filled just looking. Even the brass case blasting ammo is for guys shooting it out on a 25yd indoor pistol range. Barely. There's good 5.56 FMJ and 7.62X39 ammo, you can tell by the cost. The steel case stuff is pretty much junk, or the people shooting are horrible shots.

 

[TMan51]

I always clean new firearms before the initial range visit, just to be sure the bore and chamber don't have microscopic metal chips, crud, or some other debris present.

The new Ruger's I've encountered with a couple recent purchases have hammer forged barrels. Checking them with my bore scope, they are the smoothest barrels I've ever seen.
I also do the pre-shoot clean on rifles that come home, and it takes a few passes with a mild bore cleaning solution, (I'm old, so I still use Hoppe's and a cotton patch), and it takes a few passes before the patches come out clean. My guess is the hammer forge process uses a lube of some kind. I swab the chambers with the RamRodz I get from Midway.

 

[TMan51]

i think the problem may be with the rifling twist, which is 1:9.

I've been shooting and hunting with .223's for about 40 years. The 1:9 twist is possibly the best thing that ever happened to the 5.56/.223 round. The only snag with the 1:9 and faster is some bullets will self destruct, often as close as 25yds or so.
My current crop of .223/5.56 rifles with a 1:9 twist includes a Ruger Hawkeye Predator/22" barrel, a Mossberg MPV/18" barrel, and a home built AR/16" barrel. The shorter barrel on the AR will stabilize a Hornady 68gr BT Match and/or a 70gr Speer SSP out to 300yds. The Ruger Hawkeye is a 1/2 MOA at 100yds, closer to 1 MOA at 200yds, and 300yds with 55gr to 70gr bullets. I also have 1:7 and 1:8 barrels, but I have not played with bullets heavier than 70gr. There doesn't seem to be any "penalty" with the faster twist barrels and bullets as light as 55gr, or as heavy as 70gr.
Sighted in dead on at 200yds, most bullets land about 1.5" high at 100yds and 8" low at 300yds from the Hawkeye, the drop in velocity for the 6" shorter barrel sighted in for 200yds is closer to 2" high at 100yds and 10" low at 300yds.