Awesome info.
I’m hoping I can hit the range today or Saturday. I’m fired up now.
After doing that a while, I’ll spring for high dollar match grade ammo and give it a run.
I second B_Smith. The results on that target at 50 yards, first time shooting an AR I believe as well, will get the job done for it’s intentions. If you are looking for marksman results, you will need plenty more practice. Most of us are not limited by our weapon, but our own ability to get the most out of it.
If you are looking to be a competitive marksman with it, then I can’t tell you anything, because I am not. But if you want to have your DD as a defensive weapon, you are on the right track. Once you are fairly satisfied that the sights are “on”, I would practice at 25, then 50, then 100 yds as others have said.
I would also start shooting from the shoulder w/out the bench, that is where you will gain confidence in knowing that you can reliably hit a target closer to real world scenarios.
I have had my DD XVM for over a year and I am still shooting iron sights, partly because I want to be proficient with them and partly because of budgetary reasons. You have a good rifle, practice with it to wring the most out of it.
Another factor to consider is your vision. Are your eyes healthy? Are you a bit older?
The front sight post width issue might be bugging you in a very subtle way. If you factor out the 3 rounds at 6 o’clock, what remains is a decent vertical cluster strung out a bit horizontally just above the center of the target area. IMO that left-right string suggests that you might have a bit of difficulty getting a really clear focus on that post. The aperture size is a good thing to consider too, as previously noted.
Nearing forty, I still have what is technically 20/20 vision, but I can tell it’s not as clear as it was 20+ years ago. I tend to print slightly horizontal groups now, using the irons, at ranges of 50-100m. Maybe you’ve got similar issues?
I’m, as my daughter would say, “40 and a half”. 
I also have 20/20 vision, but like you can definitely tell a difference in how quickly my focus changes, etc. I’d imagine you may be onto something there.
I can’t wait to try with the smaller aperture to see if it makes any difference. If it doesn’t then I’m guessing this focus thing and the front site post size is part of the issue.
The smaller aperture may help me to focus on it better too. Looking through a pin hole at something can clarify a picture for someone who doesn’t have good vision, so this may have the same effect.
This may be of help in shrinking your groups, I find it helpful myself. I noticed your target is kind of on the large size. I have found that if I use a target that is, say, no more than about 2" at fifty yards with no magnification, that it really gets me to be much more consistent in placing the front sight. You may have already done this next one, sandbag the rear of your rifle. And finally, really concentrate on a good, straight back squeeze on the trigger.
Oh btw, thecolter put up a 50 yd target on the optics forum that looks pretty good for sighting.
That looks good. Does anyone have that 25 yard target PDF that extrapolates the group out to 50/100 yds, etc?
I only have the actual pdf and print outs. That has been a HUGE help for me, since i have terrible eye sight (until LASIK)
This one?
http://www.lawofficer.com/sites/default/files/UPdated25yrdSightInTarget2.pdf
*Don’t forget to confirm at your actual “Zero” distance (50 or 100yds).
The small aperture should make a big difference. The big one is for close quarters and for low light shooting out to 200yds max (torso hits, not tight groups)
CATI
Enjoy it while you can- I’m not as lucky as oldman time is catching up with my eyes! I can still shoot the AR irons pretty well but other types are a real pain- so most of my guns now where scopes! :rolleyes:
If you’re fairly new to the AR, I’d spend some time ensuring I understood sight picture, steady hold, how to use the trigger. Manuals are good.
6 O’clock hold as others have said - after a while you start to know exactly when you are “on”.
Ubung macht den Meister.
It will come - it is a great rifle with a great barrel.
I am not a fan of iron sights… What I am really saying is that I shoot like crap with iron sights. That is an acceptable group at 50 yards. I found that after about 1000 rounds or so, my DD barrels seem to tighten up. I also shoot DRASTICALLY better with a red dot. Keep up the good work.
Thanks guys. I go shoot tomorrow. I’m sure the small aperture will help some.
I bought some smaller targets too.
I have my front sight tool in order to adjust for a 6 o’clock picture as well.
I’ll post results tomorrow night!
I’m loving this rifle. I got my bore guide and single piece rod today and gave it’s first bath. 
I know I’m just re-dirtying it tomorrow but really just wanted to clean it to tinker with it and get to know it better. It’s so sweet.
Second time at the range finally zeroing in my SPARC 2.
Shooting 62 grain (reloaded) soft points @ 50 yards.
14.5" PSA CHF barrel
To answer your question, the reason your groups aren’t good is FUNDAMENTALS. I recommend getting some training in the fundamentals of rifle marksmanship. Project Appleseed puts on a weekend course for only $60 that does a great job of this. Bring your AR, 400 rounds of ammo, at least 2 mags, and a sling, and they will make you a more effective Rifleman. It is a great basis for anywhere you want to go with your training. www.appleseedinfo.org
This thread is almost four years old, OP is not even active anymore.