Chad Wallace

April 12, 2025

Guns, Gear, review

SRU SARB-15 Bullpup Chassis

Chad Wallace

April 12, 2025

Guns, Gear, review

SRU Bullpup Chassis

Review

SRU Precision has brought out some pretty nice AR bullpup conversion kits. If you have been thinking about getting a bullpup, the SRU kit might be the way to go. The SRU AR15 bullpup chassis comes in a number of configurations to help you choose the right system for you.

To sum up the SRU Bullpup Chassis, it is a 2 piece shell that wraps around an AR15. Not the full AR, just a mil-spec receiver and an upper. There is a stipulation on the style, or type, of upper receiver you use. A standard one can be used, but you will need to get a short recoil system. If you do not want to go this route, any bufferless upper should work. These include the Jakl, BRN-180, or what I used, the Foxtrot Mike Gen 2. The 2 piece shell is made from a carbon fiber infused polymer, which gives it extra strength and rigidity.

Installation of the SRU chassis can be time consuming. There are a lot of screws and pieces that hold the SRU Chassis around the AR lower receiver. Using the Foxtrot Mike upper made it a little bit easier. Luckily SRU has some detailed online instructions. Let’s just say that this is not the easiest kit to assemble. First, you have to take out most of the SRU Chassis’ screws. Then you will have both sides apart to start putting in the parts. Next install the short buffer tube into your lower receiver with the proper parts for your chosen upper. Then install the lower receiver assembly into the chassis. Make sure you have removed the trigger guard from the bottom of your receiver, or the SRU chassis will not work. Adjust the trigger travel screw. The SRU chassis uses a trigger linkage, which is why it needs adjustment. There is also a QD forward mount that needs to be installed and adjusted. This forward mount holds the bottom of the upper receiver in-line with the chassis. Now you can reassemble the two halves. Trust me, I simplified this for the review. I probably had the chassis apart 3 or 4 times to get all the parts adjusted correctly.

The trigger system is what really makes the SRU Bullpup Chassis shine. Since the SRU kit uses an aluminum trigger linkage, you get a good trigger. Bullpups are notorious for having bad trigger pulls, but SRU seemed to solve this problem. Another advantage to the SRU kit is that you can choose any AR15 trigger to install. That is because the trigger is actually in your AR receiver at the rear of the bullpup. The SRU kit does add about 1 pound to the total trigger pull weight. I used a Black Talon Tactical 3.5 pound trigger and it ended up right at 4.5 pounds. SRU made the chassis with a flat trigger and a single sided safety. These are pretty decent. If you do not like them, you can change them out for any mil-spec trigger shoe or any AR safety that you like, including ambi ones. You can also take the triggers pre-travel out by shimming it, the instructions just don't explain how to keep the shim in place.

The SRU Chassis does not come with a pistol grip. This is not a big deal. I installed a Thril pistol grip because I like them. Even though it worked well, I soon realized that a more vertical grip would work much better. This is because there is not much room between the pistol grip and where the chassis drops down to accommodate the magazine, and the magazine itself. It is pretty minor, and I still have the Thril grip on it. I also found the length of pull to be long. SRU states 15.3 inches, which seems about right. If you have short arms, it might be harder to reach the trigger than with a standard AR.

I should probably mention a few differences when using the SRU chassis. The mag release comes to mind first. It uses a lever style behind the magazine, similar to an AK style. It works well for me, but it did take some getting used to. Another thing to note is that you may need a higher than usual optics mount. This is because your cheek rests on top of the receiver, on the little pic rail cover SRU supplies. First I mounted up a red dot. Then I went to the ZeroTech Thrive HD 1-8 in a standard cantilever mount with a riser. Lastly, a 1.93 Geissele mount was added. It put the scope up high enough to use without a riser.

Foxtrot Mike was kind enough to send me the upper for the SRU Bullpup. That way I could just drop in the upper and not have to worry about short stroke kits. The upper Foxtrot sent is their brand new monolithic style upper receiver. It uses their forward charging system and a built-in buffer/spring recoil system. This particular monolithic system uses a 1 piece barrel, gas block, and barrel extension. It also uses a 308 size bolt for more strength. The Foxtrot upper has a full 16 barrel and comes with a threaded on A2 flash hider. This system with the SRU chassis made a really nice bullpup. The barrel sticks out just far enough so that you do not feel like you are going to shoot your hand off.

Now it is time for the love-hate experience. Okay, more love than hate. I was not sure how I would like this bullpup in the beginning. It surprised me. I really like how compact it is. The forward charging upper with the SRU kit makes it easy to cycle with the gun up on your shoulder or while running the gun. Magazine changes are fairly quick, even if I can do an AR mag change faster. The whole thing weighs 7.25 pounds without a mag or optics. So it handled pretty decently for me. Plus the weight is toward the rear, so you are not trying to swing a heavy weight back and forth between targets. Since I did not shim the trigger, there is a bit of take up before you get to the trigger's break. I just did not want to take it apart again to shim the trigger. You will also notice in the pictures that the scope mount is turned around backwards. This was done on purpose so that the physical mount would not get in the way of the forward charging handle. You can turn it around to the normal position and it will work. I just didn’t like my hand rubbing on the mount.

If you like bullpups, or maybe just want to try one out, the SRU Bullpup Chassis kit may be a good fit. The quality of the kit is top notch. It probably has one of the best bullpup trigger systems around, at least in how it feels. The polymer chassis feels good and not cheap. I ended up really liking the SRU bullpup chassis. Head over to SRU and check it out.

Firearms Insider Reviews - Key Points

Claim to Fame:

Bullpup conversion for AR15 rifles

Target Market:

Anyone wanting a top quality bullpup

Features, Benefits, and Specifications of this product:

LOP: 15.3”
OAL with 16” barrel AR15: 26”-29”
Kit OAL: 20” (without handguard) / 25” (with handguard)
Weight: 980g (without handguard) / 1320g (with handguard)
Shell: PA66+CARBON FIBER injection molded
Trigger Linkage System: 6061 T6 CNC machined
Short Buffer / Sling Mount Endplate: 6061 T6 CNC machined
Trigger / Safety Selector / Mag Latch / Rail & Front Adaptor: Metal Polymer
Stock Recoil Pad & Cheek Pad: TPU
Optional Front Handguard: Steel stamping
AR-15 Lower Receiver: Mil-Spec only
AR-15 Upper Receivers:

Bufferless complete upper, e.g., BRN-180 / FM-15 / JAKL
Mil-Spec Upper + short buffer BCG, e.g., DFA MCS 2.5” BUFFER / LAW TACTICAL ARIC / CMMG 5.56 to .22 conversion BCG

What other aesthetic options or finishes are available?

Black, Tan, with or without handguard

What others are saying?:

Nothing notable as of publishing

Link to other reviews:

Recoil Web

Price point:

MSRP = $429.99

Retail = same

I need it now! Availability:

SRU Precision

Our Rating:

Pros:

Uses mil-spec AR lower receivers
Uses any AR15 trigger
Trigger system is top notch
Compact
Decent design

Cons:

Assembly can be tedious
Needs tall optics mount
Long length of pull
Extra safety selector at rear of rifle

Score: 7.50 Good

Favorite Link: Foxtrot Mike FM-15 review

Rusty Odom

March 9, 2025

Gear, Review

TIMBER CREEK ENFORCER 10/22 CHASSIS

Rusty Odom

March 9, 2025

Gear, Review

TIMBER CREEK

ENFORCER 10/22 CHASSIS REVIEW

We all go down rabbit holes sometimes, especially when we start trying to modify our firearms to be a symbol of ourselves. Well I did this with my Ruger 10/22. It took me a year to almost finish the build and I am now close to 100% complete with it. I received a Timber Creek Enforcer Chassis for the 10/22 rifle, as the title entails. Right off the bat I noticed that I had gone out to left field and was in trouble. So I put the chassis on the rifle and noticed that it was a lot lighter than my original wood stock version that came on my varmint edition rifle. I started making a list of things to change that would make the chassis suited for what I thought it deserved. This is the beginning of the rabbit hole.

The Timber Creek chassis itself weighs around 22 ounces. Now I don't know what a wood stock weighs but it is a heck of a lot more. The rifle with the original barrel seemed a little unwieldy. It had a long barrel so the forearm for the chassis system seemed short. This is where I ordered a new barrel from Byers Barrels. This barrel was a liner type, ultralight 16.5” barrel. This made the rifle better. Well I soon realized I needed a trigger system and reached out to TandomKross. I then received a trigger pack from them. I thought the 10/22 was complete, not hardly. Well, I needed an ultra light bolt, lightweight scope mounts, extended charging handle, and a Vortex optic. Now here is the fun part, do I use a buffer tube or does it need a folder on it? So stand by and I will tell you.

The Enforcer chassis is a skeleton style system that is straightforward to install on any of the standard 10/22 rifle systems. Just take the barrel and action out and drop it in the chassis. Use the screws that come with it and you're done. Install your favorite AR style grip, then you get to decide how to finish off the rear of it. It has buffer tube threads on the rear, so you can install a tube and your favorite stock on the rear. I opted for a screw in folding adapter that I ordered for a TC rifle years back. I installed a buffer tube and a stock I had laying around.

Now to the good stuff and out of the rabbit hole. The chassis is machined out of aluminum and machined very well I might add. It has M Lok slots machined at the 3, 6 and 9 o'clock positions for your favorite accessories. The chassis up front has a lot of machined holes to decrease the weight. Where the forearm meets the main body, it is machined at an angle and has 4 lines machined in it. I assume this is for resting the rifle on a barricade, a limb, or what have you to get a stable shooting position. Down the side it is a little thicker, this is where the action drops in, yet it is angled and radiused for a smooth feel. The rear of the system has direct holes machined through it. What for? I am not sure, but it is cool looking. Then the end has the threads for the buffer tube.

The Timber Creek Enforcer 10/22 chassis comes in numerous colors from mild to wild. I opted for just the plain black anodized color. Timber Creek also has systems for numerous other style rifles, like the Remington 700 and AR 15. The website does not have all the specs that I would usually add to the review. I can tell you this chassis turns your rifle to a top notch plinker or something that is ready for your local .22lr precision match. This chassis system is just the base for what you can do. It is a great foundation to build a 10/22 to your heart's content. The only thing lacking here is your imagination for when you get started building. Again, I am not completely done with mine because there is always something more to add to it.

Firearms Insider Reviews - Key Points

Claim to fame:

Lightweight chassis system

Turns the ordinary rifle into a different style rifle

Target Market:

People that want AR style in a non AR rifle

Those that want personality in their rifle

Competitive shooters

Those whose choose quality and value

FNBs (Features & Benefits of this product):

Quality machined aircraft grade aluminum
Hard anodizing or Cerakote finish
Easy installation
Weight: 1.4 pounds
Uses AR buffer Tube
M-Lok mounting slots

What other aesthetic options or finishes are available?

Numerous different colors

What others are saying:

First Impressions

The moment you pick it up, you can feel the premium quality. Made from lightweight, aircraft-grade aluminum, the Enforcer chassis doesn’t just look good—it’s built to perform. And the anodized finishes? Chef’s kiss. Whether you’re into sleek black or want to make a statement with vibrant red or blue, Timber Creek has styles for everyone.

Link to other reviews:

Nothing found as of publishing

Price point:

MSRP - $399.99

I need it now!

Timber Creek Outdoors or Optics Planet

Our Rating:

Pros:

American Made
Lightweight
Great customer service
Easy installation

Cons:

I feel it needs a longer forearm
Website is lacking specs

Score: 8.00 Great

Chad Wallace

July 2, 2023

Review

Strike Modular Chassis (SMC)

Chad Wallace

July 2, 2023

Review

After using the Strike Industries Strike Modular Chassis for the Sig P320, I am finally letting you know my thoughts. The Strike Modular Chassis - Alpha series, or SMC for short, is made to drop in your Sig P320 fire control unit and slide. This gives you a more controllable platform with a bunch of different accessory options.

In the box with the Alpha series Strike Modular Chassis are a bunch of other accessories. You may or may not choose to use them, but they are there. Of course there is the Alpha series SMC. But along with the SMC is an optics platform, a side charger adapter, a set of gray grip panels, and an angled front grip that also will hold an extra magazine. Various screws and allen wrenches are also included to install all that stuff. There are also some added bonuses. Like a mini figure SMC for those brick toys, a SMC patch, and a SMC pin. Those little add-ins are pretty cool.

I’ll try to explain the SMC to you, but the pictures may explain it better. It is machined from 6061-T6 aluminum, so it’s not your Grandma's plastic grip. As it sits, it looks like a pistol frame with an extension running off of the back. The extension has some QD’s on it, along with a vertical picatinny rail for attaching stuff, like a pistol brace, when they become legal again. Along this extension is also where the raised optic platform mounts. Up front is a standard picatinny rail section for attaching lights or the supplied angled foregrip/extra magazine holder. Oddly enough, there is also a hole through the front pic rail which is used to mount compensators, more on that later.

At first, I dropped my P320 FCU and a full length 4.7” slide into the Strike Modular Chassis. The FCU slid in pretty easily, but still fit snug. This slide had an optic already mounted to it, so I left it for the time being. I also installed the charging handle on the rear of the slide. One basically swaps out the backplate and then screws the charging handle on, on whatever side you want to use it on. Strike Industries also sent me their Dual Folding adapter, or folding brace. So I installed this on the rear pic rail. This was before using a brace was a problem. I also installed the foregrip. I shot it a while in this configuration. I might mention that where the rear pic rail is on the SMC, it has a “U” shaped cut-out, so you can see your iron sights or slide mounted red dot easier. While using this config, I did notice that the changing handle rubbed a little bit on the side of my optic. The charging handle moves with the slide, so it doesn't rub along the optic, it just rested up against it, causing the vibration of the firearm to rub a little wear mark in the side of the optic. The charging handle really did make it easy to cycle the slide, I can see why Strike Industries now offers it as a stand alone product. Other than the rub mark, I was pleased with how the SMC was working.

After a bit, Strike Industries sent out some more accessories to attach to the SMC. They sent the Magwell, Blast Shield, and 2 compensators. I immediately installed the Magwell as it makes reloads easier. I also installed the Blast Shield. The blast shield mounts up on the front pic rail. It gives the slide some “shields” to keep muzzle blast at bay. It also protects your hands when using one of the compensators. The Blast Shield has a lower pic rail also, so rail attachments can still be used, they just sit slightly lower on the firearms frame. I couldn’t immediately install the comps, because I needed a carry length slide with the 3.9” barrel. Zaffiri Precision was kind enough to help me out with one so that I could use the compensators.

The compensators come in two sizes, a Small and Large. The Large one has more mass and more ports, but it also is longer so it sticks out past the blast shield or dust cover. The Small comp is flush with the blast shield and barely sticks out past the pistols dust cover. Both of these comps are for non-threaded barrels only. This makes the comps 50 state legal. The comps come with a screw to mount them. They mount through the SMC’s dust cover in that previously mentioned hole. Just slide the comp into the SMC and tighten the screw. These comps will only work with the SMC and a 3.9” slide/barrel. I tried out both the comps and really liked them. The Large version seemed to reduce recoil and muzzle rise better than the Small one. But don’t get me wrong, the Small comp still did an excellent job, the Large one just worked a bit better. I would choose the Zaffiri compact slide and Small comp combo when the SMC is configured as just a stand alone pistol.

The Strike Industries SMC doesn’t come without problems. Since the SMC is a modular style chassis, it screws together in places. Mainly where the backstrap slides in. At the top, there are 2 tiny screws to hold it in place. These 2 screws loosen up and can strip the frame holes out. Strike industries now says to use “red” loctite 272 on these. They still loosened up on me and one of the screw holes completely stripped out. Luckily it was on the side where a longer screw can go. So I put a screw with a nut on it and it works fine now. Once I figure out which backstrap I want to permanently use, I will be doing something semi-permanent. So if you get one of the SMC’s, use a red threadlocker on these screws and check the tightness of them after every use. The backstrap, where the web of your hand meets it, is flat. This flat makes the pistol rub your hand a bit. If Strike Industries were to round this out, the SMC would be way more comfortable in your hand, especially after a day of hard use.

When I switched to the compact slide and compensator, I also started using the raised optics mount. The raised optic mount has mounting holes for just about any mini or micro pistol red dot, like an RMR, Shield, etc. The red dot mounting seems pretty high when you look at it, but when you are using it, it works well and doesn’t seem too tall. I really like how it has the ability to mount just about any optic.

The Strike Modular Chassis is a unique addition to your Sig P320. It gives you abilities that the stock P320’s don't. The fixed, non reciprocating optic mount works well. The compensator options are great. Having an angled front grip that houses an extra magazine is very useful, especially since you can put a 30 rounder in it. The screws that strip out are a big downer for me. But as a whole, the Strike Modular Chassis is a fun and useful addition to a Sig P320.

Firearms Insider Reviews - 8 Key Points

Claim to Fame:

Chassis system for Sig P320 handguns

Target Market:

Those wanting to convert their Sig P320 into a pistol caliber carbine or SMG style pistol

FNBs (Features & Benefits of this product):

SMC ALPHA BASE:

Over 20+ configurations
Included Ambidextrous Side Charging Handle with Slide Cover Mount
SMC Rear Module Backstrap
SMC Multi-Optic Mount (Footprints: C-More, DeltaPoint Pro, Docter/Noblex, RMR, Shield and all SIG SAUER Open Reflex Sights)
Ambidextrous QD sockets located on SMC Rear Module Backstrap
Picatinny rail located at front bottom of chassis and on Rear Module Backstrap for accessories
Spare Magazine Holder for SIG SAUER P320 with SI Modular Magazine Release is included
Uses SIG SAUER P320 OEM fitment takedown lever and P320 magazine release, SI Modular Magazine Release is pre-assembled and included
Machined from 6061-T6 aluminum

SMC COMPS: For use with 3.9” slide and non-threaded barrel