You can havetrigger work done, 5lb trigger pull is minimum
Here are some other things that can affect accuracy:
1-As already stated several times you are using the wrong target
2- grab the rear sight aperture does it move side to side? If so replace the spring sight cover
3- grab the gas cylinder can you rotate it? If it moves any at all you need to
een" the barrel splines
Stock Fit is a huge factor in accuracy:
4- Unlatch the trigger guard and remove, turn rifle upside down in your lap. Grab the barrel in one hand and hold the stock in the other. Push ,pull on the barrel, does the action move in the stock? If there is any movement you will need a new stock, you cant bed it to be JCG leagal
5- Insert the trigger group how far away from the action does the end of the trigger guard stop before it gets hard to close.
If there is little or no resistance either the triggerguard lugs are worn or stock is compressed or both.
Stock and or gaurd will need replaced . You cant shim the trigger guard are and be JCG legal
6-Front handguard should be able to "slightly" move back and forth, should not be tight against lower band abd gas cylinder
7- Rear handgaurd should have a very small gap between lower band and reciver
8- stock ferrule should be ight on stock and have a gap between it an the lower band
9- lower band should fit tight on barrel, not movearound
10- Look at the muzzle is it dented or dinged? If it is dinged on the oustide of the crown its fine, if inside you should be it recrowned
11- as already stated you need to check Muzzle Wear
12-sight picture, are you using 6 0'Clock hold?
13- If you were shooting off a rest off bench do not set front handguard on rest. It is open on the bottom and op rod can rub rest affecting accuracy
14- tilt test, is usually a function test but if the op rod rubs hard it can affect accuracy
http://www.youtube.com/watch?v=tlIoxbtdPXY
15- practice, practice, practice
I'm sure I have forgot something but this will give you some things to check