Rainier Arms Build of the Week – LWRCI SMG45 Pistol

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Rainier Arms Build of the Week - LWRCI SMG45 Pistol
Rainier Arms Build of the Week – LWRCI SMG45 Pistol

U.S.A.-(Ammoland.com)- It’s been a while, but the build of the week is back. This week we’re bringing out one of the hottest sub guns on the market, the SMG 45 pistol from LWRC International.

This particular SMG 45 was at Range Day at Triggrcon 2019 as well as a range demo for Rainier. With over seven thousand rounds fired, we have had zero malfunctions. We’ve shot numerous types of 45 ACP ammunition through it, both suppressed and unsuppressed and so far this thing has held up like a champ and shoots like a dream. There is a reason why this sub-gun, in particular, is at the top of everyone’s favorite list. But that should be expected from a company like LWRC.


LWRCI SMG45 Pistol
LWRCI SMG45 Pistol
LWRCI SMG45 Pistol
LWRCI SMG45 Pistol

The SMG 45 is not exactly a brand new gun. It was announced 5 years ago to address a contract solicitation. From there the company has been turning them out in limited numbers to fulfill that order, but this year they finally made the move to bring it to the consumer market. It’s up against a plethora of 9mm pistol caliber carbines offered by so many different companies. The 9mm round is great for certain applications and is very cheap, making it easier to shoot more without breaking the bank. But, very few reliable options exist for the 45 ACP platform.

In simple terms, the SMG 45 is the perfect marriage of the standard AR-15 controls we know and love with a short recoil-delayed blowback system. Most pistol caliber carbines utilize a more simple direct blowback system which is easier to produce and considerably cheaper. The cons of this are a heavier bolt system which relies on a buffer with a strong recoil spring which beats up AR15 trigger groups and other internal parts.

The beauty of the delayed blowback system used in the SMG 45 is that it delays opening the bolt until the pressures are lower, allowing them to use a smaller and lighter weight recoil system. This allows the design to be considerably lighter compared to other options. The gun itself weighs 5.9 pounds but feels solid, and durable. The pistol has fully ambidextrous controls and is compatible with AR15 trigger groups as well as safety selectors. The only real departure from typical AR controls is the addition of an HK style paddle mag release, which isn’t a big issue once you start running it.

LWRCI SMG45 Pistol
LWRCI SMG45 Pistol

We’ve set up our SMG 45 with a few extras that up the shooting capability of this weapon even more. Lights on guns is a commonplace nowadays and especially for the home defense weapons, which this would be a great candidate for. We’ve chosen to put on the Cloud Defensive OWL which is flat out the most durable light on the market. With 1250 lumens at 50,000+ Candela, this will light up whatever you need to see. Although a bit big, the light has an integrated pressure pad and mounting system that compliments the SMG 45 nicely.

Our next addition might be a bit controversial for some, but like many things it comes down to personal preference, not just looks. We fitted our SMG with a Unity Tactical FAST Riser Mount and put on a Vortex UH-1 Holographic sight. Yes, it looks a bit funky, but for those of us who have got to run this for a while, it makes a big difference in shootability. A higher mount brings the head up a bit higher which allows for a better heads up profile when on the range.

The suppressor on the end of the weapon is the Sig Sauer SRD45 which features a Grade 9 titanium tube and 17-4PH stainless steel baffles allowing for a lightweight and durable option. Shooting the SMG 45 suppressed is a thing of beauty and with that short delayed blowback system, it is very quiet.

In the end, I do believe the SMG 45 is worth nearly three thousand dollar price tag. Yes, you can find other sub guns for cheaper, but you will be hard-pressed to find something else that shoots 45 ACP and is as relatable and feels as good to shoot. There were a number of us at the shop who were skeptical of the weapon system when we first saw it, but after putting thousands of rounds through it over the last month or so, we can honestly say it is one of the best sub guns on the market.

If you're looking to start your next project, be sure to check out our site. Check out the products below for the parts used in this week's build.

Look out next week for our next build breakdown!

About Rainier ArmsRainier Arms logo

Rainier Arms was started by enthusiasts for enthusiasts. We specialize in high-end AR15s/M16s, parts & accessories. “If we won't use it, we won't sell it.” Founded in 2005, Rainierarms.com already has more than 2547 unique products, and growing. Our technical advisory team consists of enthusiasts, law enforcement, & military personnel that continue to make our offerings unique and desirable in the market place. www.rainierarms.com.

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They need to make this in 10mm. In 10mm, I might be able to overlook that ridiculous price point. LWRC makes really good guns, but $3000 for a pistol caliber carbine in .45 ACP is too much.