I too like the KNS ant-rotational pins, and I have them installed on most of my AR's. Firstly, they're functional, but IMHO they also compliment the aesthetics of the rifle.
Of course, they are indeed another "do-dad" for your rifle. So, why not? Right?
aawrenchbndr is correct on the size that you need to order (.154"). +1!
With regards to your question about "creep", I personally don't think the KNS pins would do the trick. I could be wrong, but the anti-rotational pins are just that...the stop the pins from rotating in the receiver, in order to mitigate any undue wear to the pin holes on the lower receiver.
Now, I do have a couple of suggestions:
#1 => As others have mentioned, the RRA National Match two-stage trigger is an exceptional
trigger at a reasonable price. And, it's something a novice armorer can install (just take your time and ask questions if you get stuck).
If you go with a RRA NM two-stage trigger, you'll immediately notice a difference. Keep in mind that with a two-stage trigger, there there will be some "take-up" in the trigger, before the hammer releases. THIS IS BY DESIGN!
A two-stage trigger helps the shooter to gauge when the hammer will fall. In short, as the trigger reaches the second stage, you know the hammer will release with slight additional pressure.
Alternatively, with a single-stage trigger, you simply have to "know" your trigger's release point. And, this can be slightly more difficult to determine and/or train yourself to.
For some (like my brother, a military-guy and qualified expert marksman), a two-stage trigger is NOT preferred. For others, they swear by a two-stage trigger. So, the point is that it will come down personal preference. And...with practice...you can become a proficient shooter with each.
OK...sorry, I rambled there. Now onto the second suggestion.
#2 => Since I have replaced my factory triggers with either a Chip McCormick single-stage match trigger, or the Rock River Arms NM two-stage trigger, I have several factory triggers/hammers lying around in my gun case.
Anyway, I ran across a video on youTube regarding "tweaking" a factory AR-15 trigger, in order to remove the "take-up" in the trigger. So, I figured I'd give it a go. Again, I had some spare parts lying around. So, what the heck?
Now, over the winter I put together my recent AR-15 build, my Yote-Getter
. So, I decided I would try this trigger modification for it, just to see if it worked.
Anyway, after doing the "mod" and working the hammer (as is shown in the video) the trigger was surprisingly crisp. It definitely took away the "slop/creep" you may experience with a standard/factory AR-15 trigger.
I've shot my Yote-Getter with this trigger job, and I thought it did quite well. Of course, it's not a "match" trigger, but for the price ($0), I was definitely impressed. In fact, I'm thinking of doing it again for a future AR-15 build.
So, if you're game, this might be a good...and CHEAP...option for you to consider.
As far as the difficulty scale (1-10), I'd rate this "mod" a 2 or 3. Again, just take your time and be patient.
Before I give you the video link, I have to offer a disclaimer.
Remember, you're modifying the fire control group in a high-powered rifle. This, by the very nature of this "mod", it can be very dangerous. More importantly, if you do something wrong, and you damage the functionality of the fire control group, this could lead to personal injury or death. (I'm not trying to scare you, but 'dems the facts.)
In other words, any modification made to your AR-15 fire control group should be done with great care. And, you should function-test the rifle as you go, as well as once it is fully assembled in a safe manner.
My apologies for the disclaimer, but keep in mind, if a "mod" breaks-bad on you, it can become a VERY serious matter for you or someone else. And, we don't want that, right?
OK...here's the link:
Also, there is a trigger job listed as a sticky in the AR-15 talk section:
Let us know how it goes.