I just bought my first bow (Martin Exile) on Saturday. I am using a 60 lb draw weight and 29.5 inch draw. It's a great bow and all but I have one problem. When I'm practicing shooting, I can shoot perfect groups all the way out to 25 yards.

However, when I get to 30 yards I am not consistent with my shots. One will be high and the next will be far right. Is this because I am doing something wrong? Or is it something with my sight?

Could be a problem with your setup. Although it is more likely you just need some practice it takes some time, just keep at it!

alot of factors..the wind is always a factor the further ya go out. maybe yer tired...if ya dont shoot everyday, dont start now...ya gotta werk up to shooting 10 shots a day er ya could mess urself up.
a good anchor point is the key..i use the spot under my ear just above the jaw bone...you should be able to open and close ur mouth with out moving the knuckle.
could be the spine on yer arrows...the arrows dont fly straight, they wabble all the way to the target, so if its wabblin alot, it wont necessarily hit the same spot every time if its wabble is an inch er more.
always make sure your sights and rest are tight.

Hard to say. Keep in mind you are a beginner and be realistic about accuracy. At 30 yards there is not that much more to contend with than you do at 25, but it is a considerable distance. Yes, there is a tad more drop and maybe ... .10 sec +/- more time for a cross-wind or weak form to push the arrow off line.

Might I make a suggestion? It could be an issue with you holding so long, trying to cut your aim so fine, that you mess up your form .... or begin to drift. Try developing a rythmn. Loosen your grip. Relax the riser hand. As soon as you are on target release, and "follow through" by focusing on the arrow's flight ... I refer to this as me "becoming the arrow".

If you are developing shooting strength, don't rush it. Approach the practice like beginning to weight train. Warm up before you start to shoot. Stretch. Start off slowly ... concentrate of form for now ... say 5-10 arrows/day at very close range aiming at a tiny target spot .... add 2-3 shots every other day or so ... work up to 50-75 arrows/session, you will be in decent shooting shape. Back up a few yards every week or two. If you have room, eventually practice out 60-80 yards. Sounds rediculous, but I promise you if you become confident at 75 yards or so, 30-40 will seem like 10 yards does now. And besides, shooting at 75 yards +/- is great fun.

Practice at weird angles. The seldom seen, dead on broadside shot, at 15-20 yards is almost mythical in the real woods. Practice on days when the wind is blowing hard, shooting purposely cross wind. It'll be an education if you have never tried it.

Coould be that 60# is too much for now. An old, superb archer showed me a cool and simple method that he said (and I agree) "measures" your optimum draw weight. Find a folding chair or stool (no arms). Sit 90 deg to a close by target (10-15 yards). Put your riser straight in front, arrow mounted. Carefully holding your balance lift both feet off the ground. Then lower them until your toes are just barely touching. Now draw straight back in one easy smooth motion, emulating a slow draw so as not to spook a close by deer. When you get to full draw, turn slowly to the target ... hold for 15 seconds +/- ... release for accuracy. If you can do this comfortably, your draw weight is OK. If you struggle, (cannot hold steady, in pain, have to "crank the bow back", lose you balance, struggle to hit dead center, etc.) either increase your strength until it is easy, or drop the draw weight. This advice comes from Clarence Yates, who I watched hit the 100 yard "Elephant" dead in the kill zone, 5 for 5 at the Harlan Hill traditional archery shoot some years ago. Best shooter I have ever known personally.

Thanks Mojotex, I will try out those tips. I definately know that I hold the bow too long and that could be why I am a little sporadic.