I agree with olredhead. I don't like firelapping. These 223's are deep throated enough without taking some more off.... Handlapping or running 1000 rounds through it, either one is what I would do. For immediate results I'd use hand lapping. But for the fun factor, a break in p-dog hunt would be more fun.
Also like redhead said, check the crown, or have the crown recut or pollished.
Also, the usual, be sure your scope mount hasn't worked loose, rings are tight, butt stock bolt is tight, sand bagged under hinge pin, etc. And these 223's have a 1-12" twist, so in general they like smaller bullets (55 grains and smaller). You might try some more 40-50 grain offerings. How often are you cleaning the barrel? Might try cleaning more and cleaning less. Some barrels like it clean, others like it fowled up a little (not alot...). What optics do you have? For sub moa groups a 6-18 or 6-24 (or 8-32, fixed 40x, etc....) are typically alot better than a typical 3-9x40 scope. Also, try different targets. I have targets laying around with 6" black bulls, 1" black bulls, 1" orange squares, etc. Given the thickness off the crossairs, magnification of the scope, lighting conditions at the range, etc all targets are not all the same, some your eyes will be able to see better. Does the rifle surpise you when you pull the trigger? if so, alot of people will say good, I say bad, I want the rifle to go off when the cross airs are dead center over the bulls eye. Know your trigger and the groups will shrink. What's your shooting position at the bench? Feet, shoulders, etc? Does your cheak/butt stock have the proper cheak weld? You might want to look into a cheak pad if not. Do you have only one sand bag? I like having two, one under the henge pin, one under the butt stock. After lining everything up I hold onto the rear bag with my off hand, not the butt stock. Are you shooting with a full breath in your lungs or have you exhailed first? Most people shoot better with a half full or empty (or near empty) chest of air.
Do you have any friends that are bench shooters that can take you out and look at your shooting position to see if it looks stable, consistant, etc? Also, another set of hands shooting your rifle is always a good indication if it's something the shooters doing wrong or the rifle.
whew. Gotta give the old fingers a rest. :wink:
later,
scruffy