A characteristic of many AR-based MSRs is that they rattle. Specifically, there is slight play between the upper and lower receivers, even with high priced MSRs.
I have viewed and read about various techniques to eliminate the upper-to-lower rattle and decided to settle on one method, the UTG Accurizing Wedge AR-15. Like any product, one that works for one person may not be another person’s choice. This one; however, works for me and my Windham Weaponry “SRC” MSR.
Note: Product may require trimming for ideal fit.
It seems that what is contained in the note is what has generated negative reviews of the product. The good news is that the product “can’” be trimmed to fit and that a gunsmith is not required to do the work. The bad news is that you may actually be required to work with some fine sandpaper, emery cloth, or an emery board to make it fit correctly. In severe cases, I recommend an X_ACTO knife and a steady hand.
The UTG Accurizing Wedge AR-15 is actually a piece of molded polymer that has a stiff feel to it, but can be compressed – up to a limit. The limit is what is adjustable and, as such, may take more work in different MSR lowers than others.
The fit is more ‘felt’ than anything else. The bottom of the Accurizing Wedge consists of a circular “ledge” that is approximately 1/32” (0.03125 inches or 0.79375 millimeters) in height. To obtain what I felt was a comfortable fit; I removed approximately 1/64” from the base. So, what were my guidelines for the fit (which may vary from person to person)?
First of all, I did not feel the need to use excessive force in attaching the upper to the lower. Secondly, I wanted a rattle free upper-to-lower fit, but not at the expense of having to remove the rear take-down pin with a tool (pin pusher or a loaded cartridge), or for that matter, have to use a tool to install the rear take-down pin.I have read where purchasers of the Accurizing Wedge have trimmed the bottom with an X-Acto knife. Given the material of the Accurizing Wedge, which is similar to that used in Shok-Buff systems to dampen recoil, the use of an X-acto knife can lead to misery (and, perhaps, some slicing and dicing of digits of the hands). I have also read of folks using Dremel tools and even hand sanders. I prefer, instead, to use a flat surface and a simple emery board whenever possible. However, there may be extreme cases where surgery on the Accurizing Wedge is absolutely required (more on that later in the article).
A little sanding of the bottom, a test fit, and more sanding and test fitting gave me what I felt was the perfect fit. I rotated the Accurizing Wedge as I sanded to help keep the base even
With the MSR on a padded Surface, I can simply push down (with little effort) on the rear of the upper until the rear-take-down pin slides into place. To remove the rear take-down pin, some simple pressure on the rear of the upper allows me to push the take-down pin by hand where I can pull the pin free from the right side without any effort or special tool that I may not have in the field (or at the range).
My Windham Weaponry ‘SRC’ is now rattle free and I feel good about that. The cost of the part was $2.99. The cost of feeling good is priceless. I don’t feel that there is a strain on the MSR by having the UTG Accurizing Wedge AR-15 in place and that gives me confidence in the MSR.
Given the cost of the part, I can afford to have several on hand and ready to install, since everything wears over time and use.
THE SEVERE CASE:I mentioned earlier about “severe cases” and installing the UTG Accurizing Wedge AR-15 in the Ruger AR 556 proved to be one of those cases. The area for the Takedown Pin on the Ruger SR556 is quite a bit shallower than that of the Windham Weaponry “SRC”. Light sanding of the UTG Accurizing Wedge AR-15 was out of the question; this would take some serious surgery. In fact, about 3/4 of the base of the UTG Accurizing Wedge AR-15 was removed to achieve an acceptable fit. Essentially, the UTG Accurizing Wedge AR-15 was laid on its side and a #2 X-Acto knife was used to cut away the base of the UTG Accurizing Wedge AR-15. Essentially, the base was reduced from 1/4-inch to 1/16-inch in this case.
The wedge was installed in the Ruger AR 556 and after applying slight downward pressure on the upper, the Takedown Pin slid into place. The upper-to-lower fit of the Ruger AR 556 is now tight as a drum. The Takedown Pin is tight; tight enough to warrant a push with the tip of a round, or a brass roll pin punch, to force it out of its detent and enough to pull it the rest of the way with the fingers.
A rattle-trap of a vehicle does not instill confidence that the vehicle will get you home. Likewise, a rattle-trap of a rifle does not instill the confidence that I want during my time of need. The UTG Accurizing Wedge AR-15 works, and if little things count, this UTG Accurizing Wedge AR-15 thing counts for a lot in my book.
UTG Accurizing Wedge AR-15: http://www.midwayusa.com/product/518277/utg-accurizing-wedge-ar-15 and other fine on-line retailers.