@macgrumpy - I am by no means saying it is a "cure all" for accuracy issues. It certainly wont turn a 4 MOA gun into a sub MOA monster but it does make a substantial difference over the factory wood and synthetic non-bedded stocks available from SAI. It is definitely heavy though! Mine is around 14-16lbs loaded up. Love the ergo's and the lack of recoil though!
It certainly was NOT a perfect love story for me though. I spent considerable time a.) putting the Sparrowhawk Faux Selector Lockout kit in, b.) tweaking points of contact between the bolt carrier and the stock, and c.) doing what the stock set out to do. I was shooting 100 rounds every week or so of handloads using 175gr Tipped Match Kings and could not get them to group better than 1.5 MOA. I tried everything and it culminated in a phone call to Troy and speaking with their gunsmith "Ed" who actually told me the intended purpose of the stock.
Few people know that the MCS is designed to secure the receiver properly to free float the barrel like the Sage EBR and Blackfeather stocks do. What I found is that some of the common "fixes" for the M1A do not work in this stock. First: shimming the gas system is a no-no. This binds the front band on the MCS so that the barrel operates like a traditional ferule setup. This is NOT how it was designed to be used and no amount of front end tension ever made that setup accurate. Ed told me to take the shim out and let the gas lock do it's intended job. He said that shimming the gas system is a good "fix" for not having a unitized gas system, but is detrimental to accuracy in the MCS stock.
I did put his "word" to the test though and pulled the entire front block off the rifle and free floated the barrel. Groups improved slightly but not a lot. I went to look at the front block to see if it was contacting and sure enough, it was contacting the block in multiple locations. Relieved these locations and the block went back in without increasing group sizes. That block is only there to hold the top rail and bottom rails together.
Second, he mentioned the tension screws for the trigger pads. He described the level of force required as being "substantial" and that the force required and described in the install manual is a starting point and that "more" was what he found to work best. It didn't take much more for me to get tight groups and prevent the receiver from moving in recoil. I'm somewhere between 3/16" and 1/4" from the trigger when the trigger group tightens up instead of the 1/8" they recommended in the manual. This drastically reduced the "settling" time for the action after cleaning from 40 rounds to about 10.
The last big change I did was to drop the 175gr Tipped Sierra Match Kings for the standard 175gr SMK. This dropped my groups to where they are now in the 1" to 1.25" range. The velocity of those rounds is about 2550 and QuickTarget is saying these will fall subsonic at 1050 yards at that velocity. Interestingly enough, QuickLoad's barrel time feature says that pushing a 175gr SMK at about 2600 FPS should yield a tighter group and none of this batch of handloads in the 41.5gr of IMR 4064 got close to 2600 FPS (fastest was about 2570). With the cases I'm using (MKE from the ZQI M80 ball at Walmart) my case capacity is about 2gr higher than LC brass is and 41.5gr of 4064 in LC brass produces around 2600 FPS with a 175gr SMK. There may be sub MOA groups in this rifle with the factory barrel.
The last point Ed said was to "ditch" the M1A/M14 action for any accuracy work and buy an AR10. He said he built himself a super nice double lugged, Kreiger heavy barreled M14 in a McMillan fiberglass stock and has rarely shot it. He said he bought an AR10 with match barrel and hasn't looked at that M14 in a long time. Of course, I personally don't care for the AR15/AR10 action for the "fun" factor and recognize the accuracy for dollar value they represent, but it isn't my type of rifle for this type of work.
That all said, the two biggest issues with the M14 platform that control accuracy are the barrel and front end tension (either none [free float], or a lot) are easy to address if you buy the right one to begin with. I started with a SAI Loaded (July 2015 build) and had already bought a used Criterion 1:11 twist, Med profile 22" barrel to replace the factory barrel... that was before I switched back to SMK's over the TMK's. Had I bought the National Match, I probably wouldn't have put it into a Troy MCS stock and it would have shot the same groups as I'm currently getting. The next M1A/M14 I will own will be custom build with the proper barrel from the beginning. What stock I put it in will be up for debate at that time.
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