First, this is the Handy Rifle with the SLR Rifleworks Sentry 7 set screw (melonited) gas block at setting 7 from full closed. I’m running an A5H0 buffer with a Springco GREEN spring.
Ammo was Federal XM193 55gr Brown box.
Magazines were Magpul 30rd PMAGs gen M3.
EFAB was tested first, then I walked back to my car, switched devices, and tested the MAMS. Same gun. Same ammo. Less than 15 minutes apart.
Both devices were attached and timed using the Precision Armament stainless shim set. No POA/POI shift was observed out to 50 yards.
Very special thanks to Jerrysimons for loaning me the MAMS and shipping it to me on his dime for the benefit of the M4C community. Also thank you to my buddy Jon who did the camera work. Couldn’t have done it without you, buddy!
Thoughts, impressions, and the review proper will come later. I’m moving to a new unit in my agency (a promotion), but my free time is at a premium lately. Might not be till the weekend.
However, I’ll leave you all with a brief spoiler: my guess about how they would perform was spot on…and they are the cream of the crop for currently available muzzle devices, IMHO.
My buddy, the cameraman, had his 16" BCM ELW fluted with 13" KMR, BCM comp, and A5H2 buffer on deck as well…though it’s apples and oranges.
REVIEW:
Course of fire was 4 rounds standing with a reasonably firm hold on the gun, 4 rounds with the forearm resting in my open hand, and 4 prone with a semi-firm position behind the gun.
Not everybody weighs 230+ and lifts heavy, so me getting an Iron Mike grip on the gun would simply allow zero gun movement and give the videos zero value. Moving along…
PA EFAB:
As I stated in my previous reviews of same, it allows virtually no muzzle rise in my normal shooting stance and, in the video, still very little shows on camera. It’s recoil pulse is stronger, but slightly smoother than the KAC MAMS. It has no flash and it adds very little (if any) additional back pressure into the gas system. Muzzle movement at 15 yards remains circular within a 3-4 inch circle even with a loose hold. With a firm hold, at the same yardage, net muzzle movement is under three inches and follow up shots can be pressed at will, as often as desired. Shots from prone resulted in no discernable rocking motions from front to rear.
KAC MAMS:
The MAMS keeps muzzle movement very low and is also an extremely neutral brake (no muzzle rise or muzzle dip). Its recoil pulse is slightly sharper, but overall was weaker than the EFAB’s, and both were straight to the rear. The difference is so slight, I doubt I would have been able to draw the distinction if I had not fired them back to back. The MAMS added so little additional back pressure over the EFAB (which itself is identical to an A2 in my testing), that they appear to be nearly identical. The additional gas system pressure created by the MAMS is so minimal, that the same setting was used on the gas block for each. See the next paragraph for clarity. KAC clearly did a ton of research to ensure that gas system pressure was not unnecessarily increased over a flash hider, and it is readily apparent. Way to go KAC and PA as this is a huge benefit of these designs. The KAC has some relief cuts around the exit aperture that the EFAB does not have. These apparently work to nullify the effects of the gas expansion chamber inside the device (which would normally boost gas system pressure by a bunch, much like a suppressor does).
The MAMS 15 yard muzzle movement remained in a roughly 2-3 inch circle with a loose hold, and was also in a basically circular pattern. Follow up shots could be taken at will.
GAS DRIVE:
For this test, to ensure proper evaluation of gas system drive (and parity between muzzle devices), I set up the SLR Sentry 7 such that it would cycle the XM193, but not lock back on empty in the EFAB (setting 7 from closed). The MAMS did not lock back on any of the strings of fire except the prone string.
FLASH:
Flash was occasionally seen as a dull glow near the ports on the MAMS, while none was observed from the EFAB. I also ran Tula through both and the results were the same. Keep in mind this is through a Rainier Arms Mountain Series 18" barrel.
FINDINGS:
If anything stuck out to me, it was how remarkably well and how remarkably similar these two muzzle devices performed. Honestly, on a heavier gun, with more gas drive, it might be impossible to differentiate them except maybe for flash on some ammo, in the near dark. No additional blast or concussion that I was able to detect as the shooter over an A2. None. No adverse effects on gas drive.
Really, it comes down to what your goal is for your particular gun. If you want a mount for a (KAC) can, the MAMS is simply a foregone conclusion; nobody else is even close to this level of refined performance for a can mount. If you are shopping for a non mount, then the EFAB must be considered. The EFAB’s ability to rival true flash hiders in terms of real world flash suppression is impressive and sets it apart from most other non mount muzzle devices.
Original EFAB impressions thread:
https://www.m4carbine.net/showthread.php?t=158818
MAMS:
http://vimeo.com/118647503
EFAB:
http://vimeo.com/118647680
&
