View Full Version : Rainier Arms Samson Evolution Rail

19 July 2011, 23:03
I've been on a huge rail system kick lately. So when I got an opportunity to try out a Rainier Arms 12 inch Evolution free float rail produced by Samson Manufacturing, I jumped on it.

Keep tuned here for my review...


From the Rainier Arms website:

The Samson Evolution Series is the next step forward in free floating hand guards. Light weight and durable, these hand guards offer the perfect upgrade for 3 gun shooters, LE/Military and weekend enthusiasts alike. The 1.8” facetted O.D. offers a comfortable shooting platform for most shooters. Accessory rails can be added or removed easily to adapt the hand guard to your specific needs (units can also be mounted at 45 degree offsets). This version of the Evolution Rail is a Rainier Arms exclusive.


■The thermal bushing locks onto the stock barrel nut
■No special tools required for installation
■The inside diameter is large enough to fit most suppressors (1.56”)
■Continuous mil spec top rail
■Duel anti rotation tabs
■Relieved for most gas piston systems
■Thermal Bushings helps reduce heat transfer to hand guard
■Tube Matl 6010 T6, Bushing Matl. 303 Stainless
■Mil-spec Hard coat Anodized
■Weight: 11.0oz w/Heatsink
■Length: 12.37″
■Rails Included: QD Swivel Socket, 2 Inch Rail, 4 Inch Rail
■Standard AR-15 barrel nut required; not included.

26 July 2011, 19:27
Let’s face it. When it comes to rails and fore ends for your AR platform rifle, there seem to be a metric ton of choices these days. Spending time over the past few months experimenting with just a few of the newer options out there, I’ve started to really appreciate some of the nuances that make for a well designed rail system.

Not long ago, Stickman posted “The Mother of all Rail Articles” here: http://militarytimes.com/blogs/gears...rail-articles/. If you’re trying to select a rail system, you really should read this article. Stick does an excellent job talking about some features that mark a well designed rail system. With this article in mind, I’ll do my best to give you a tour of one version of Samson Manufacturing’s Evolution series of rails…

The Rainier Arms version of Samson’s 12 inch Evolution rail has everything I look for in a rail system, and some additional features that appealed to me both as a builder and as a shooter.

The EVO rail is free floating and provides a continuous top rail that creates a monolithic look and function for the entire length of the upper assembly. The 12 inch version is actually 12.37 inches in length, and so I installed this one on a mid-length upper with a low profile gas block.


I’m not opposed to rail systems that use proprietary barrel nuts, but I’m not a big fan of systems that require a non-standard or proprietary wrench to tighten that nut. The EVO rail avoids the added expense of special tools, by utilizing the standard barrel nut. You simply install the included thermal bushings over the barrel nut. The clearly illustrated included instructions show how to orient the two bushings and simply snap them onto the barrel nut.



These thermal bushings also act as a heat sink designed to help dissipate heat before it’s transmitted to your hand through the rail.

This particular rail came with three modular pieces that fill my needs well: one four inch rail, one two inch rail, and one QD swivel socket. Installing them is pretty intuitive. Not only can they attach through the holes that run along the 3 o’clock, 6 o’clock, and 9 o’clock positions, but they can also attach along the triangular vent holes that run between those positions.


With your accessory rails already attached, it’s time to slide the EVO rail over the thermal bushings.


You’ll note that the EVO rail has two anti-rotational tabs that extend along the side of the upper receiver…a critical design feature for any rail system in my opinion.


The EVO rail, like several other designs, secures with two tension screws that tighten the rail against the thermal bushings/barrel nut. These two screws should be tightened evenly to ensure the rail isn’t torqued out of proper alignment.


With everything Locktited and tightened up, you're done with the install...


To finish off this build I installed a Magpul AFG onto the 4 inch rail section. With the two inch rail at the 3 o’clock position near the end of the rail, I’ve got this set up perfectly for my preferred shooting style.



Final initial impressions…

I can’t really put into words how great this particular set up feels when I take a shooting position. I’ve got what I’d consider medium sized hands. With the AFG mounted on the rail, the EVO rail is the perfect outer diameter for my grip.

Cosmetically, I also prefer Rainier’s triangular cuts to the “S” cuts typically found on the Samson rails. It seems to me that they may actually allow for better ventilation too.



I’m really looking forward to hitting the range soon so I can give the Rainier Arms Evolution rail a real workout..


26 July 2011, 19:35
Please post any questions and discussion here: http://www.weaponevolution.com/forum/showthread.php?3297-Rainier-Arms-Evolution-Rail-Discussion&p=30660#post30660