What if ... ?

[Jerry R]

Over the years, I have assembled around two dozen AR platforms. Most were to sell when I had an FFL. I have noted with great interest the builds being created by members here. Some pretty cool stuff being done by some very talented people. I started wondering what if someone wanted a custom build and they …

a) Didn’t have all the tools required.
b) Didn’t feel they have the ability.
c) Didn’t want a readily available off the shelf build.
d) Had some very specific requirements that were not stocked by dealers.
e) Just didn’t want to do it themselves.

Would someone like Rainier Arms accept a parts list and build-to-spec something “special”?

So, I browsed their web site looking at my idea of dream pieces for a new upper for the SBR. The parts I selected (along with required adjuncts) were:

Rainier Arms Stainless Match .223 Wylde Barrel – 14.5” Midlength 1:8 Twist
Rainier Arms UltraMatch Billet Upper Receiver – MOD 2 (M4 Feed Ramps)

Syrac Ordnance .750 Set Screw Low Pro Adjustable Stainless Gas Block
I wanted an adjustable GB for suppressor use. I also wanted the barrel drilled so the Gas Block could be pinned in addition to the set screws. The Syrac has a dimple in the appropriate location for drilling the barrel.

Gas Tube – Midlength
Gas Tube Roll Pin
Rainier Arms BCG – Precision Match Grade Nickel Boron
Fortis Hammer Charging Handle – Black Teflon
AAC 5.56 51T Muzzle Brake – timed but NOT pinned – suppressor mount.
Troy Front Folding Battle Sight – HK Style (not installed)
Troy Rear Folding Battle Sight – Not Installed
BCM KMR KeyMod Rail 5.56mm 13”
Assembly Fee
Gas Block Pinning Fee

I called Rainier and spoke with a technician. Nine days later the upper arrived at my door. Washington to Florida has to be a couple of days.

Could I have put it together myself – yes. Could I have purchased a built upper from anyone’s inventory – yes. Were the assembly charges less than the cost of all the tools required to put it together – not really sure, but would be very close. The workmanship was first class and backed by Rainier Arms.

Does it shoot? Oh yeah !

I put the new upper on the LWRC SBR Lower running their factory buffer spring and H2 buffer. Sight-in and shooting was done at GriffonSec’s range.

I was actually surprised with the Troy Sights this time. I have them on most of my AR’s, and sight-in is always interesting (remember the box of chocolates line). This time, the vertical alignment of the front sight was “first shot perfect” and the windage was only off a couple of inches to the left at 25 yards. Empties ejected about six feet away between 3 and 4 o’clock. The empties moved a little closer to five o’clock with the suppressor on it, but not enough “over-gassing” to warrant adjusting the Syrac GB.

After adjusting the irons, I put a Leupold Mark AR Mod-1 1.5x4 Scope in a LaRue LT-104 QD mount on it. After a single shot zero (shoot one round, move the cross hairs to the hole) the next five rounds at 25 yards went into a single hole less than a half-inch wide. Grouping at 100 yards with PMC .223 Remington 55 Grain FMJ consistently shot less than ¾”.

We ran a few drills with it on 12” steel at ranges from 35 to 125 yards and there were zero issues of any type with the unit.

I was impressed with the BCM KMR. I had not handled one, and selected it for this upper based on comments posted here about its’ diameter and weight (the great photos didn’t hurt any either). I wanted a rail running full length, as close to the muzzle threads as I could get, and the 13” rail on a 14.5” barrel has the “look” I was after. I tried to come up with an analogy for the size of it in my hand, but couldn’t. Using my thumb and middle finger around the rail, I overlap by a knuckle. I don’t use the “C” grip style, but can hold it like the small end of a baseball bat.

I added a BCM Gunfighter KeyMod short vertical grip – this worked very well for me; I like stubby verticals.

This was an interesting experiment that turned out extremely well. I am very pleased with the upper, and many thanks go to the build team at Rainier Arms.

Bottom line – if you want a custom upper and you fall into any (or all) of the categories a) through e) listed above, pick out your parts and give Rainier a call.

As received from Rainier:



Upper Receiver and BCG:



AAC Brakeout:



With the Leupold and on the LWRC SBR Lower:

[Slippers]

That is really cool. Didn't know they would assemble everything. Nice pictures, too. :)

[SINNER]

Building weapons is my relaxation but what a fantastic option for all the reasons you listed above.

And that turned out perfect. Nothing not to like about that weapon.

[GOST]

+1 on what Jerry said, the work I've had done at Rainier Arms has always been great. And very nice pics Jerry.

[Computalotapus]

That is a sweet looking rig Jerry

[Jerry R]

Thanks Guys - much appreciated. I think it will prove to be a "go-to" rifle. With the Wylde chamber and adjustable GB, I should be able to run just about anything through it.

[six8]

Very nice. How do you like the Fortis Hammer?

[Jerry R]

How do you like the Fortis Hammer?

It functions as designed. I am used to the large latch-handle on the Gunfighter, but close enough for me. Downside of using a scope that overhangs is that no handle is large enough for speed use. Knowing that, I have no complaints on the Hammer. I may try one of the new Avalanche charging handles. Knobbies on both sides may overcome that shortfall. I think the Fortis on a rifle with RDS or irons would be as good as any available.

[Txfilmmaker]

Great looking rifle and a great option for custom work.

Sent from my iPhone using Tapatalk

[BoilerUp]

That is a sweet looking rig Jerry

Should we call it the "Jerry Rig"? <chuckle/>

Nice upper. I really like the KMR. Hard to believe any barrel can get that kind of accuracy out of PMC.

[Aragorn]

THAT is nice!

[UWone77]

Jerry, that is a sweet upper. I remember you talking about getting this together awhile ago. Glad you got it exactly the way you wanted it. I can vouch for the main armorer at Rainier. He does quality work, and has un-fubared a couple of things for me.

The only problem is... there is not enough copper fouling on the 51T Muzzle Brake.

[Jerry R]

there is not enough copper fouling on the 51T Muzzle Brake.

Thanks UW - the "big" pic of the 51T was when it was a virgin; and several platforms needed attention at GriffonSec's that week. Only managed to put a couple hundred through the new upper. Also, the NIB BCG stained more than I thought it would, cleaned easy enough, but the (suppressor?) staining won't come off. Also had a factory defective Wilson TTU in the Sig 716. New trigger from them is in, and function tests fine, but need to range check that one again. Oh, the stress of it all, mandatory trips to the range ---------- will it ever end ????

[SINNER]

Jerry, that is a sweet upper. I remember you talking about getting this together awhile ago. Glad you got it exactly the way you wanted it. I can vouch for the main armorer at Rainier. He does quality work, and has un-fubared a couple of things for me.

The only problem is... there is not enough copper fouling on the 51T Muzzle Brake.

gas tube and brake inversions?

[Aragorn]

Jerry, you may have made my life more difficult. Here I was leaning towards a Mega billet upper and Wedgelock, but now I'm half thinking Rainier Billet upper and KMR! They actually pair quite nicely...