"Smooth" is good.
When you get to shoot as many different ar' configurations as paul and i do, the difference the little things make become more easily noticed and appreciated. We like our custom uppers to run "smoothly". It is a difficult quality to quantify. See new AR' guy's critique of our 6.8 SPC upper several years ago on the uppers, lowers, etc., forum, where he comments at some length on this quality in our winning entry.
Another noteworthy example regarding this "smooth" running quality came from a Special Forces weapons guy who took one of our 10.5" guns on deployment to the rock box. He said in training up with the new weapon, he had to recalibrate his "feel" for the platform. In his words, "it feels like the bolt is closing on an empty chamber every time, when in fact it is feeding properly." He also reported confirmed hits on some "man-size" targets at 600 yd with it. Yes, it was a sub-moa 10.5". Maybe coincidental - but probably not.
A gun that runs more smoothly implies one that runs more reliably, more consistently, and with with better accuracy. Also, a shooter can run a smooth gun faster than one that has the typical "choppy" quality to it.
We place great emphasis on getting the best quality components built to the highest tolerances in our custom builds. This means "straighter" parts, producing less friction. Another critical aspect of a weapon's "smooth" qualities are optimum porting for the gas system, recoil spring, and buffer weight, as well as proper lubrication. The ionbond diamondblack coating on the bolt carrier group components that mstn pioneered also is a big contributor to this.
It is accepted as fact at this point in time that a mid-length gas system in a 14.5" to 16" barrel produces a smoother felt recoil pulse, less wear and tear on the weapon, as well as enhanced reliability than the original format carbine length gas system. Sound suppressor usage tends to greatly exacerbate these differences, too. As a result, we would never consider using a carbine length gas system in a custom 16" build. Mid-length has been the proven way to go in the 16" for some time now.
When the new Knight's Armament SR15 E3 hit the streets, I was most impressed with what an outstanding job they did in balancing the recoil spring and buffer with the gas pulse in their longer than standard mid-length gas system. This rifle is as smooth running as you can find, even at its ultra-light weight, and represents a tremendous value for the money. Wearing just a generic A2 flash hider, it produces less apparent recoil than some uppers with compensators.
You'll note that the KAC SR15 E3 utilizes Knight's own peculiar mid-length gas system, longer than the "industry standard" mid-length. This I felt was a large part of their success. But they wanted $39 each for this gas tube ...
... So we turned to another pair of industry innovators, Noveske and Vltor, who came up with their own "intermediate" length gas system for 18" SPR use, within a fraction of an inch of that used by Knight's. It is #3 in the below photos:
I tried this intermediate length gas system in 18" builds and felt that it offered an actual decrease in the qualities we were after. It felt "choppy" compared to the rifle elngth gas system in an 18" build. But what about in a 16" upper?
Two identical uppers were built up with each of the Noveske barrels shown, one with the traditional mid-length gas system, and one with the new intermediate length. Matching Nightforce scopes were installed, and a side by side test was performed. Both shot equally well (0.60 moa), but the new gas system produced a "smoother" weapon with less apparent recoil.
We are so impressed with this new intermediate length gas system in the 16" that we're going to make it a part of our future custom offerings. We're even going to be able to step down another size on the gas port.
Good shooting,
Wes Grant
MSTN
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